Merge pull request #949 from telemt/me-pool-convergence

ME: Autonomous&Lifecycle-bounded Pool Convergence

Cargo.lock

@@ -2780,7 +2780,7 @@ dependencies = [
 
 [[package]]
 name = "telemt"
-version = "3.5.13"
+version = "3.5.14"
 dependencies = [
  "aes",
  "anyhow",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "telemt"
-version = "3.5.13"
+version = "3.5.14"
 edition = "2024"
 rust-version = "1.88"
 

src/api/config_edit.rs

@@ -158,7 +158,7 @@ async fn prepare_patch_to_path(
 ) -> Result<PreparedConfigPatch, ApiFailure> {
     // 1. optimistic concurrency
     let loaded = load_config_snapshot(config_path, false).await?;
-    let current = compute_snapshot_revision(&loaded);
+    let current = compute_snapshot_revision(&loaded.source_contents);
     if expected_revision.is_some_and(|expected| expected != current) {
         return Err(ApiFailure::new(
             hyper::StatusCode::CONFLICT,
@@ -208,6 +208,8 @@ async fn prepare_patch_to_path(
     let mut merged = Toml::try_from(&old_cfg)
         .map_err(|e| ApiFailure::internal(format!("failed to serialize config: {}", e)))?;
     deep_merge(&mut merged, &patch_toml);
+    ProxyConfig::validate_decoy_source_keys(&merged)
+        .map_err(|error| ApiFailure::bad_request(format!("invalid patched config: {error}")))?;
 
     let requested_cfg: ProxyConfig = merged
         .clone()
@@ -263,7 +265,7 @@ async fn prepare_patch_to_path(
     }
 
     // 4. classify the validated, normalized candidate.
-    let revision = compute_snapshot_revision(&candidate);
+    let revision = compute_snapshot_revision(&candidate.source_contents);
     let new_cfg = candidate.config;
     let class = classify_config_changes(&old_cfg, &new_cfg);
     let deferred_process_fields =
@@ -306,7 +308,7 @@ fn reload_submit_failure(error: ReloadSubmitError) -> ApiFailure {
 /// Returns only the editable config sections and current revision.
 pub(super) async fn read_managed_config(config_path: &Path) -> Result<(Toml, String), ApiFailure> {
     let loaded = load_config_snapshot(config_path, false).await?;
-    let revision = compute_snapshot_revision(&loaded);
+    let revision = compute_snapshot_revision(&loaded.source_contents);
     let parsed = Toml::try_from(&loaded.config)
         .map_err(|error| ApiFailure::internal(format!("failed to serialize config: {error}")))?;
 
@@ -457,3 +459,7 @@ mod tests;
 #[cfg(test)]
 #[path = "config_edit/conveyor_tests.rs"]
 mod conveyor_tests;
+
+#[cfg(test)]
+#[path = "config_edit/decoy_dns_tests.rs"]
+mod decoy_dns_tests;

src/api/config_edit/decoy_dns_tests.rs

@@ -0,0 +1,105 @@
+use super::*;
+
+const SOURCE: &str = r#"
+[access.users]
+alice = "000102030405060708090a0b0c0d0e0f"
+[[server.listeners]]
+ip = "127.0.0.1"
+port = 18080
+transport = "web"
+web_trusted_proxy_cidrs = ["127.0.0.1/32"]
+[web]
+enabled = true
+[[web.vhosts]]
+host = "proxy.example.com"
+public_addr = "203.0.113.10:443"
+[web.vhosts.decoy]
+mode = "http_upstream"
+upstream = "http://localhost:18081"
+resolve = "startup"
+[[web.vhosts.profiles]]
+user = "alice"
+secret_mode = "dd"
+"#;
+
+#[tokio::test]
+async fn decoy_dns_api_get_and_mutation_base_need_no_prepared_runtime() {
+    let directory = tempfile::tempdir().unwrap();
+    let path = directory.path().join("config.toml");
+    std::fs::write(
+        &path,
+        SOURCE.replace("localhost", "unresolvable.example.invalid"),
+    )
+    .unwrap();
+    let (managed, revision) = read_managed_config(&path).await.unwrap();
+    assert_eq!(
+        managed["web"]["vhosts"][0]["decoy"]["resolve"].as_str(),
+        Some("startup")
+    );
+    assert!(managed["web"].get("decoy_dns").is_none());
+    let (base, base_revision) = crate::api::config_store::load_config_for_mutation(&path, None)
+        .await
+        .unwrap();
+    assert_eq!(revision, base_revision);
+    assert!(base.web.runtime.is_none());
+    assert!(base.web.decoy_dns.origins.is_empty());
+}
+
+#[tokio::test]
+async fn decoy_dns_api_patch_without_reload_prepares_before_disk_write() {
+    let directory = tempfile::tempdir().unwrap();
+    let path = directory.path().join("config.toml");
+    std::fs::write(&path, SOURCE).unwrap();
+    // This current-thread runtime exercises the real Tokio resolver without nested block_on.
+    let active = ProxyConfig::load_prepared(path.clone())
+        .await
+        .unwrap()
+        .config;
+    let before = std::fs::read(&path).unwrap();
+    let mut vhosts = serde_json::to_value(&active.web.vhosts).unwrap();
+    vhosts[0]["decoy"]["upstream"] = Json::String("http://localhost:18080".to_string());
+    let error = apply_patch_to_path(&path, &serde_json::json!({"web": {"vhosts": vhosts}}), None)
+        .await
+        .unwrap_err();
+    assert!(error.message.contains("overlaps WEB listener"));
+    assert_eq!(std::fs::read(&path).unwrap(), before);
+    assert!(active.web.runtime.is_some());
+
+    let prepared = prepare_patch_to_path(
+        &path,
+        &serde_json::json!({"web": {"conveyor": false}}),
+        None,
+    )
+    .await
+    .unwrap();
+    assert_eq!(prepared.desired_config.web.decoy_dns.origins.len(), 1);
+    assert!(prepared.desired_config.web.runtime.is_some());
+    assert_eq!(std::fs::read(&path).unwrap(), before);
+    apply_patch_to_path(
+        &path,
+        &serde_json::json!({"web": {"conveyor": false}}),
+        None,
+    )
+    .await
+    .unwrap();
+    let reloaded = ProxyConfig::load_prepared(path).await.unwrap();
+    assert!(!reloaded.config.web.conveyor);
+}
+
+#[tokio::test]
+async fn decoy_dns_api_rejects_resolve_on_static_mode_before_serde_drops_it() {
+    let directory = tempfile::tempdir().unwrap();
+    let path = directory.path().join("config.toml");
+    std::fs::write(&path, SOURCE).unwrap();
+    let base = ProxyConfig::parse_source(&path).unwrap();
+    let mut vhosts = serde_json::to_value(&base.config.web.vhosts).unwrap();
+    vhosts[0]["decoy"] = serde_json::json!({
+        "mode": "static_directory", "directory": directory.path(), "resolve": "startup"
+    });
+    let before = std::fs::read(&path).unwrap();
+    let error = apply_patch_to_path(&path, &serde_json::json!({"web": {"vhosts": vhosts}}), None)
+        .await
+        .unwrap_err();
+    assert!(error.message.contains("only valid for mode=http_upstream"));
+    assert_eq!(std::fs::read(&path).unwrap(), before);
+}

src/api/config_store.rs

@@ -4,7 +4,7 @@ use std::path::{Path, PathBuf};
 use hyper::header::IF_MATCH;
 use sha2::{Digest, Sha256};
 
-use crate::config::{ConfigSourceGraph, LoadedConfig, ProxyConfig};
+use crate::config::{ConfigSourceGraph, LoadedConfig, ParsedConfigSource, ProxyConfig};
 
 use super::model::ApiFailure;
 
@@ -63,7 +63,7 @@ pub(super) async fn load_config_for_mutation(
     expected_revision: Option<&str>,
 ) -> Result<(ProxyConfig, String), ApiFailure> {
     let loaded = load_config_snapshot(config_path, false).await?;
-    let revision = compute_snapshot_revision(&loaded);
+    let revision = compute_snapshot_revision(&loaded.source_contents);
     if expected_revision.is_some_and(|expected| expected != revision) {
         return Err(ApiFailure::new(
             hyper::StatusCode::CONFLICT,
@@ -98,9 +98,10 @@ pub(super) fn compute_revision(content: &str) -> String {
     hex::encode(hasher.finalize())
 }
 
-pub(super) fn compute_snapshot_revision(loaded: &LoadedConfig) -> String {
+/// Hashes source documents only; prepared DNS answers never change a revision.
+pub(super) fn compute_snapshot_revision(source_contents: &BTreeMap<PathBuf, String>) -> String {
     compute_source_revision(&ConfigSourceGraph {
-        source_contents: loaded.source_contents.clone(),
+        source_contents: source_contents.clone(),
         rendered: String::new(),
     })
 }
@@ -118,12 +119,13 @@ pub(super) fn compute_source_revision(graph: &ConfigSourceGraph) -> String {
     hex::encode(hasher.finalize())
 }
 
+/// Reads a normalized source snapshot without resolving decoys or loading static assets.
 pub(super) async fn load_config_snapshot(
     config_path: &Path,
     invalid_is_bad_request: bool,
-) -> Result<LoadedConfig, ApiFailure> {
+) -> Result<ParsedConfigSource, ApiFailure> {
     let config_path = config_path.to_path_buf();
-    tokio::task::spawn_blocking(move || ProxyConfig::load_with_metadata(config_path))
+    tokio::task::spawn_blocking(move || ProxyConfig::parse_source(config_path))
         .await
         .map_err(|error| ApiFailure::internal(format!("failed to join config loader: {error}")))?
         .map_err(|error| {
@@ -135,8 +137,9 @@ pub(super) async fn load_config_snapshot(
         })
 }
 
+/// Selects the single writable source document owning all requested sections.
 pub(super) fn resolve_single_source_owner(
-    loaded: &LoadedConfig,
+    loaded: &ParsedConfigSource,
     config_path: &Path,
     targets: &[&str],
 ) -> Result<PathBuf, ApiFailure> {
@@ -227,6 +230,7 @@ fn has_include_inside_table(content: &str) -> bool {
     false
 }
 
+/// Prepares the entire mutation candidate before any source file may be replaced.
 pub(super) async fn load_candidate_snapshot(
     config_path: &Path,
     base_sources: &BTreeMap<PathBuf, String>,
@@ -236,12 +240,16 @@ pub(super) async fn load_candidate_snapshot(
     let config_path = config_path.to_path_buf();
     let mut overrides = base_sources.clone();
     overrides.insert(owner_path, owner_contents);
-    tokio::task::spawn_blocking(move || {
-        ProxyConfig::load_with_source_overrides(config_path, &overrides)
+    let parsed = tokio::task::spawn_blocking(move || {
+        ProxyConfig::parse_source_with_overrides(config_path, &overrides)
     })
     .await
     .map_err(|error| ApiFailure::internal(format!("failed to join config loader: {error}")))?
-    .map_err(|error| ApiFailure::bad_request(format!("invalid patched config: {error}")))
+    .map_err(|error| ApiFailure::bad_request(format!("invalid patched config: {error}")))?;
+    parsed
+        .prepare()
+        .await
+        .map_err(|error| ApiFailure::bad_request(format!("invalid patched config: {error}")))
 }
 
 fn normalize_source_path(path: &Path) -> PathBuf {
@@ -265,19 +273,23 @@ fn normalize_source_path(path: &Path) -> PathBuf {
     normalized
 }
 
+/// Reads desired user and quota policy without acquiring runtime decoy state.
 pub(super) async fn load_config_from_disk(config_path: &Path) -> Result<ProxyConfig, ApiFailure> {
-    let config_path = config_path.to_path_buf();
-    tokio::task::spawn_blocking(move || ProxyConfig::load(config_path))
+    load_config_snapshot(config_path, false)
         .await
-        .map_err(|e| ApiFailure::internal(format!("failed to join config loader: {}", e)))?
-        .map_err(|e| ApiFailure::internal(format!("failed to load config: {}", e)))
+        .map(|source| source.config)
 }
 
+/// Acquires fresh decoy evidence for an explicit API reload, even at the same revision.
 pub(super) async fn load_config_for_reload(
     config_path: &Path,
 ) -> Result<(ProxyConfig, String), ApiFailure> {
     let loaded = load_config_snapshot(config_path, true).await?;
-    let revision = compute_snapshot_revision(&loaded);
+    let revision = compute_snapshot_revision(&loaded.source_contents);
+    let loaded = loaded
+        .prepare()
+        .await
+        .map_err(|error| ApiFailure::bad_request(format!("invalid runtime config: {error}")))?;
     Ok((loaded.config, revision))
 }
 

src/api/config_store/persistence.rs

@@ -113,7 +113,7 @@ pub(in crate::api) async fn save_access_sections_to_disk_if_revision(
     expected_revision: Option<&str>,
 ) -> Result<String, ApiFailure> {
     let loaded = load_config_snapshot(config_path, false).await?;
-    let loaded_revision = compute_snapshot_revision(&loaded);
+    let loaded_revision = compute_snapshot_revision(&loaded.source_contents);
     if expected_revision.is_some_and(|expected| expected != loaded_revision) {
         return Err(revision_conflict());
     }
@@ -159,7 +159,7 @@ pub(in crate::api) async fn save_access_sections_to_disk_if_revision(
         owner_contents.clone(),
     )
     .await?;
-    let _candidate_revision = compute_snapshot_revision(&candidate);
+    let _candidate_revision = compute_snapshot_revision(&candidate.source_contents);
     let revision = write_atomic_if_unchanged(
         config_path.to_path_buf(),
         loaded_revision,

src/config/hot_reload/watcher.rs

@@ -1,5 +1,8 @@
 use super::*;
 
+// Source polling and explicit reloads have distinct DNS preparation lifecycles.
+mod preparation;
+
 #[derive(Debug, Clone, Default, PartialEq, Eq)]
 pub(super) struct WatchManifest {
     files: BTreeSet<PathBuf>,
@@ -132,9 +135,21 @@ fn apply_watch_manifest<W1: Watcher, W2: Watcher>(
     }
 }
 
-/// Load config, validate, diff against current, and broadcast if changed.
+/// Builds the effective WEB snapshot without changing live state.
+fn prepare_effective_config(
+    old_cfg: &ProxyConfig,
+    new_cfg: &ProxyConfig,
+) -> crate::error::Result<ProxyConfig> {
+    new_cfg.validate()?;
+    let mut applied_cfg = overlay_hot_fields(old_cfg, new_cfg);
+    applied_cfg.validate_effective_web()?;
+    applied_cfg.rebuild_runtime_web()?;
+    Ok(applied_cfg)
+}
+
+/// Diffs and publishes a fully prepared configuration on the watcher owner task.
 fn reload_config_with_resolver(
-    config_path: &PathBuf,
+    prepared: (LoadedConfig, ProxyConfig),
     config_tx: &watch::Sender<Arc<ProxyConfig>>,
     log_tx: &watch::Sender<LogLevel>,
     detected_ip_v4: Option<IpAddr>,
@@ -142,13 +157,7 @@ fn reload_config_with_resolver(
     reload_state: &mut ReloadState,
     dns_resolver: Option<&crate::network::dns_overrides::GenerationDnsResolver>,
 ) -> Option<WatchManifest> {
-    let loaded = match ProxyConfig::load_with_metadata(config_path) {
-        Ok(loaded) => loaded,
-        Err(e) => {
-            error!("config reload: failed to parse {:?}: {}", config_path, e);
-            return None;
-        }
-    };
+    let (loaded, applied_cfg) = prepared;
     let LoadedConfig {
         config: new_cfg,
         source_files,
@@ -157,34 +166,12 @@ fn reload_config_with_resolver(
     } = loaded;
     let next_manifest = WatchManifest::from_source_files(&source_files);
 
-    if let Err(e) = new_cfg.validate() {
-        error!(
-            "config reload: validation failed: {}; keeping old config",
-            e
-        );
-        return Some(next_manifest);
-    }
-
-    if reload_state.is_applied(rendered_hash) {
-        return Some(next_manifest);
-    }
-
     let old_cfg = config_tx.borrow().clone();
-    let mut applied_cfg = overlay_hot_fields(&old_cfg, &new_cfg);
-    if let Err(error) = applied_cfg
-        .validate_effective_web()
-        .and_then(|_| applied_cfg.rebuild_runtime_web())
-    {
-        error!(
-            "config reload: effective WEB validation failed: {}; keeping old config",
-            error
-        );
-        return Some(next_manifest);
-    }
     let old_hot = HotFields::from_config(&old_cfg);
     let applied_hot = HotFields::from_config(&applied_cfg);
     let non_hot_changed = !config_equal(&applied_cfg, &new_cfg);
-    let hot_changed = !config_equal(&old_cfg, &applied_cfg);
+    let hot_changed =
+        !config_equal(&old_cfg, &applied_cfg) || !old_cfg.web_decoy_endpoints_equal(&applied_cfg);
 
     if non_hot_changed {
         warn_non_hot_changes(&old_cfg, &new_cfg, non_hot_changed);
@@ -228,8 +215,13 @@ pub(super) fn reload_config(
     detected_ip_v6: Option<IpAddr>,
     reload_state: &mut ReloadState,
 ) -> Option<WatchManifest> {
+    let loaded = ProxyConfig::load_with_metadata(config_path).ok()?;
+    if reload_state.is_applied(loaded.rendered_hash) {
+        return Some(WatchManifest::from_source_files(&loaded.source_files));
+    }
+    let applied = prepare_effective_config(&config_tx.borrow(), &loaded.config).ok()?;
     reload_config_with_resolver(
-        config_path,
+        (loaded, applied),
         config_tx,
         log_tx,
         detected_ip_v4,
@@ -282,7 +274,7 @@ pub fn spawn_config_watcher(
                 }
             }
         }
-        let initial_loaded = ProxyConfig::load_with_metadata(&config_path).ok();
+        let initial_loaded = preparation::read_source(&config_path).await;
         let initial_manifest = initial_loaded
             .as_ref()
             .map(|loaded| WatchManifest::from_source_files(&loaded.source_files))
@@ -291,7 +283,7 @@ pub fn spawn_config_watcher(
             });
         let initial_matches_disk = initial_loaded
             .as_ref()
-            .is_some_and(|loaded| config_equal(config_tx.borrow().as_ref(), &loaded.config));
+            .is_some_and(|source| preparation::source_matches_active(&config_tx.borrow(), source));
         let initial_snapshot_hash = initial_loaded
             .as_ref()
             .filter(|_| initial_matches_disk)
@@ -384,12 +376,14 @@ pub fn spawn_config_watcher(
         };
 
         loop {
+            let mut force = false;
             #[cfg(unix)]
             tokio::select! {
                 msg = notify_rx.recv() => {
                     if msg.is_none() { break; }
                 }
                 _ = sighup.recv() => {
+                    force = true;
                     info!("SIGHUP received — reloading {:?}", config_path);
                 }
                 _ = cancellation.cancelled() => break,
@@ -406,27 +400,31 @@ pub fn spawn_config_watcher(
             tokio::time::sleep(HOT_RELOAD_DEBOUNCE).await;
             while notify_rx.try_recv().is_ok() {}
 
-            let mut next_manifest = reload_config_with_resolver(
+            let mut next_manifest = preparation::reload(
                 &config_path,
                 &config_tx,
                 &log_tx,
                 detected_ip_v4,
                 detected_ip_v6,
                 &mut reload_state,
-                dns_resolver.as_deref(),
-            );
+                dns_resolver.clone(),
+                force,
+            )
+            .await;
             if next_manifest.is_none() {
                 tokio::time::sleep(HOT_RELOAD_DEBOUNCE).await;
                 while notify_rx.try_recv().is_ok() {}
-                next_manifest = reload_config_with_resolver(
+                next_manifest = preparation::reload(
                     &config_path,
                     &config_tx,
                     &log_tx,
                     detected_ip_v4,
                     detected_ip_v6,
                     &mut reload_state,
-                    dns_resolver.as_deref(),
-                );
+                    dns_resolver.clone(),
+                    force,
+                )
+                .await;
             }
 
             if let Some(next_manifest) = next_manifest {
@@ -460,3 +458,6 @@ mod path_tests {
         assert_eq!(normalize_watch_path(&linked), linked);
     }
 }
+
+#[cfg(test)]
+mod decoy_dns_tests;

src/config/hot_reload/watcher/decoy_dns_tests.rs

@@ -0,0 +1,133 @@
+use super::*;
+
+const SOURCE: &str = r#"
+[access.users]
+alice = "000102030405060708090a0b0c0d0e0f"
+[[server.listeners]]
+ip = "127.0.0.1"
+port = 18080
+transport = "web"
+web_trusted_proxy_cidrs = ["127.0.0.1/32"]
+[web]
+enabled = true
+[[web.vhosts]]
+host = "proxy.example.com"
+public_addr = "203.0.113.10:443"
+[web.vhosts.decoy]
+mode = "http_upstream"
+upstream = "http://localhost:18081"
+resolve = "startup"
+[[web.vhosts.profiles]]
+user = "alice"
+secret_mode = "dd"
+"#;
+
+#[tokio::test]
+async fn decoy_dns_watcher_publishes_dns_only_changes_once() {
+    let dir = tempfile::tempdir().unwrap();
+    let path = dir.path().join("config.toml");
+    std::fs::write(&path, SOURCE).unwrap();
+    let mut loaded = ProxyConfig::load_prepared(path.clone()).await.unwrap();
+    let (config_tx, mut config_rx) = watch::channel(Arc::new(loaded.config.clone()));
+    let (log_tx, _) = watch::channel(loaded.config.general.log_level.clone());
+    let old = config_rx.borrow().clone();
+    let mut state = ReloadState::new(Some(loaded.rendered_hash));
+    Arc::make_mut(&mut loaded.config.web.decoy_dns)
+        .origins
+        .insert(
+            ("localhost".to_string(), 18081),
+            vec!["127.0.0.2:18081".parse().unwrap()],
+        );
+    loaded.config.rebuild_runtime_web().unwrap();
+    let applied = prepare_effective_config(&old, &loaded.config).unwrap();
+    reload_config_with_resolver(
+        (loaded.clone(), applied),
+        &config_tx,
+        &log_tx,
+        None,
+        None,
+        &mut state,
+        None,
+    )
+    .unwrap();
+    assert!(config_rx.has_changed().unwrap());
+    let published = config_rx.borrow_and_update().clone();
+    assert!(!old.web_decoy_endpoints_equal(&published));
+    let applied = prepare_effective_config(&published, &loaded.config).unwrap();
+    reload_config_with_resolver(
+        (loaded, applied),
+        &config_tx,
+        &log_tx,
+        None,
+        None,
+        &mut state,
+        None,
+    )
+    .unwrap();
+    assert!(!config_rx.has_changed().unwrap());
+    assert!(Arc::ptr_eq(&published, &config_rx.borrow()));
+
+    preparation::reload(
+        &path, &config_tx, &log_tx, None, None, &mut state, None, false,
+    )
+    .await
+    .unwrap();
+    assert!(!config_rx.has_changed().unwrap());
+    assert!(Arc::ptr_eq(&published, &config_rx.borrow()));
+
+    // Explicit reload bypasses the unchanged source hash and replaces the injected endpoint.
+    preparation::reload(
+        &path, &config_tx, &log_tx, None, None, &mut state, None, true,
+    )
+    .await
+    .unwrap();
+    assert!(config_rx.has_changed().unwrap());
+    assert!(!published.web_decoy_endpoints_equal(&config_rx.borrow()));
+
+    let current = config_rx.borrow_and_update().clone();
+    std::fs::write(&path, SOURCE.replace("localhost:18081", "localhost:18080")).unwrap();
+    preparation::reload(
+        &path, &config_tx, &log_tx, None, None, &mut state, None, false,
+    )
+    .await
+    .unwrap();
+    assert!(!config_rx.has_changed().unwrap());
+    assert!(Arc::ptr_eq(&current, &config_rx.borrow()));
+}
+
+#[tokio::test]
+async fn decoy_dns_unchanged_watcher_source_skips_resolution() {
+    let dir = tempfile::tempdir().unwrap();
+    let path = dir.path().join("config.toml");
+    std::fs::write(
+        &path,
+        SOURCE.replace("localhost", "unresolvable.example.invalid"),
+    )
+    .unwrap();
+    let source = preparation::read_source(&path).await.unwrap();
+    let initial = Arc::new(source.config.clone());
+    let (config_tx, config_rx) = watch::channel(initial.clone());
+    let (log_tx, _) = watch::channel(initial.general.log_level.clone());
+    let mut state = ReloadState::new(Some(source.rendered_hash));
+    assert!(preparation::source_matches_active(&initial, &source));
+    preparation::reload(
+        &path, &config_tx, &log_tx, None, None, &mut state, None, false,
+    )
+    .await
+    .unwrap();
+    assert!(!config_rx.has_changed().unwrap());
+    assert!(Arc::ptr_eq(&initial, &config_rx.borrow()));
+}
+
+#[tokio::test]
+async fn decoy_dns_watcher_init_ignores_retained_restart_fields() {
+    let dir = tempfile::tempdir().unwrap();
+    let path = dir.path().join("config.toml");
+    std::fs::write(&path, SOURCE).unwrap();
+    let loaded = ProxyConfig::load_prepared(path.clone()).await.unwrap();
+    let mut source = ProxyConfig::parse_source(&path).unwrap();
+    source.config.web.limits.max_static_file_bytes += 1;
+    assert!(preparation::source_matches_active(&loaded.config, &source));
+    source.config.web.conveyor = !source.config.web.conveyor;
+    assert!(!preparation::source_matches_active(&loaded.config, &source));
+}

src/config/hot_reload/watcher/preparation.rs

@@ -0,0 +1,85 @@
+use super::*;
+
+/// Restart-only differences must not enqueue another DNS preparation after activation.
+pub(super) fn source_matches_active(
+    active: &ProxyConfig,
+    source: &crate::config::ParsedConfigSource,
+) -> bool {
+    config_equal(active, &overlay_hot_fields(active, &source.config))
+}
+
+/// Reads only source state; watcher initialization and unchanged events never need DNS.
+pub(super) async fn read_source(path: &PathBuf) -> Option<crate::config::ParsedConfigSource> {
+    let path = path.clone();
+    match tokio::task::spawn_blocking(move || ProxyConfig::parse_source(path)).await {
+        Ok(Ok(source)) => Some(source),
+        Ok(Err(error)) => {
+            error!("config reload: failed to parse: {}", error);
+            None
+        }
+        Err(error) => {
+            error!("config reload: source reader failed: {}", error);
+            None
+        }
+    }
+}
+
+/// Prepares fresh evidence only for changed sources or an explicit reload request.
+pub(super) async fn reload(
+    path: &PathBuf,
+    config_tx: &watch::Sender<Arc<ProxyConfig>>,
+    log_tx: &watch::Sender<LogLevel>,
+    detected_ip_v4: Option<IpAddr>,
+    detected_ip_v6: Option<IpAddr>,
+    reload_state: &mut ReloadState,
+    dns_resolver: Option<Arc<crate::network::dns_overrides::GenerationDnsResolver>>,
+    force: bool,
+) -> Option<WatchManifest> {
+    let source = read_source(path).await?;
+    let manifest = WatchManifest::from_source_files(&source.source_files);
+    if !force && reload_state.is_applied(source.rendered_hash) {
+        return Some(manifest);
+    }
+    let loaded = match source.prepare().await {
+        Ok(loaded) => loaded,
+        Err(error) => {
+            error!(
+                "config reload: preparation failed: {}; keeping old config",
+                error
+            );
+            return Some(manifest);
+        }
+    };
+    let old = config_tx.borrow().clone();
+    // Static-site reconstruction after the listener overlay must not block Tokio workers.
+    // The worker only builds data: cancellation cannot leave a detached publisher behind.
+    let result = tokio::task::spawn_blocking(move || {
+        prepare_effective_config(&old, &loaded.config).map(|applied| (loaded, applied))
+    })
+    .await;
+    match result {
+        Ok(Ok(prepared)) => reload_config_with_resolver(
+            prepared,
+            config_tx,
+            log_tx,
+            detected_ip_v4,
+            detected_ip_v6,
+            reload_state,
+            dns_resolver.as_deref(),
+        ),
+        Ok(Err(error)) => {
+            error!(
+                "config reload: effective WEB validation failed: {}; keeping old config",
+                error
+            );
+            Some(manifest)
+        }
+        Err(error) => {
+            error!(
+                "config reload: runtime builder failed: {}; keeping old config",
+                error
+            );
+            Some(manifest)
+        }
+    }
+}

src/config/load.rs

@@ -29,6 +29,8 @@ mod runtime_web;
 mod decode;
 mod effective;
 mod pipeline;
+// Candidate-owned DNS preparation is separate from pure runtime reconstruction.
+mod decoy_dns;
 mod validate_core;
 mod validate_me;
 mod validate_runtime;
@@ -74,6 +76,19 @@ pub(crate) struct LoadedConfig {
     pub(crate) rendered_hash: u64,
 }
 
+/// Normalized source configuration that has not acquired runtime DNS or static snapshots.
+#[derive(Debug, Clone)]
+pub(crate) struct ParsedConfigSource {
+    /// Source-only configuration; must be prepared before runtime publication.
+    pub(crate) config: ProxyConfig,
+    /// Normalized paths in the captured include graph.
+    pub(crate) source_files: Vec<PathBuf>,
+    /// Exact source documents used for revisions and atomic mutation checks.
+    pub(crate) source_contents: BTreeMap<PathBuf, String>,
+    /// Source-only hash, independent of DNS answers.
+    pub(crate) rendered_hash: u64,
+}
+
 /// Raw recursive source graph captured before typed deserialization.
 #[derive(Debug, Clone)]
 pub(crate) struct ConfigSourceGraph {
@@ -229,6 +244,33 @@ impl ProxyConfig {
         pipeline::load_source_graph(graph)
     }
 
+    /// Parses source without resolving decoys or creating runtime WEB snapshots.
+    pub(crate) fn parse_source<P: AsRef<Path>>(path: P) -> Result<ParsedConfigSource> {
+        Self::parse_source_with_overrides(path, &BTreeMap::new())
+    }
+
+    /// Checks decoy mode-specific keys before a source or API patch loses unknown fields.
+    pub(crate) fn validate_decoy_source_keys(document: &toml::Value) -> Result<()> {
+        decoy_dns::validate_mode_keys(document)
+    }
+
+    /// Parses an atomic mutation candidate without performing DNS.
+    pub(crate) fn parse_source_with_overrides<P: AsRef<Path>>(
+        path: P,
+        overrides: &BTreeMap<PathBuf, String>,
+    ) -> Result<ParsedConfigSource> {
+        pipeline::parse_source_graph(Self::read_source_graph_with_overrides(path, overrides)?)
+    }
+
+    /// Loads and prepares a complete runtime candidate without blocking async workers.
+    pub(crate) async fn load_prepared(path: PathBuf) -> Result<LoadedConfig> {
+        let parsed = tokio::task::spawn_blocking(move || Self::parse_source(path))
+            .await
+            .map_err(|error| ProxyError::Config(format!("config reader failed: {error}")))??;
+        parsed.prepare().await
+    }
+
+    /// Rebuilds immutable credential lookup data for this configuration.
     pub(crate) fn rebuild_runtime_user_auth(&mut self) -> Result<()> {
         let snapshot = UserAuthSnapshot::from_users(&self.access.users)?;
         self.runtime_user_auth = Some(Arc::new(snapshot));
@@ -250,6 +292,7 @@ impl ProxyConfig {
         validate_web::validate_decoy_listener_separation(self)
     }
 
+    /// Returns authentication data owned by this configuration generation.
     pub(crate) fn runtime_user_auth(&self) -> Option<&UserAuthSnapshot> {
         self.runtime_user_auth.as_deref()
     }

src/config/load/decode.rs

@@ -1,5 +1,6 @@
 use super::*;
 
+/// Typed source together with its exact include graph and rendered input.
 pub(super) type DecodedSourceGraph = (
     ProxyConfig,
     BTreeSet<PathBuf>,
@@ -7,6 +8,7 @@ pub(super) type DecodedSourceGraph = (
     String,
 );
 
+/// Decodes source while retaining the metadata needed for atomic mutations.
 pub(super) fn decode_source_graph(graph: ConfigSourceGraph) -> Result<DecodedSourceGraph> {
     let ConfigSourceGraph {
         source_contents,
@@ -17,6 +19,7 @@ pub(super) fn decode_source_graph(graph: ConfigSourceGraph) -> Result<DecodedSou
     let parsed_toml: toml::Value =
         toml::from_str(&processed).map_err(|e| ProxyError::Config(e.to_string()))?;
     handle_unknown_config_keys(&parsed_toml)?;
+    ProxyConfig::validate_decoy_source_keys(&parsed_toml)?;
     let general_table = parsed_toml
         .get("general")
         .and_then(|value| value.as_table());

src/config/load/decoy_dns.rs

@@ -0,0 +1,204 @@
+use std::future::Future;
+use std::time::Duration;
+
+use super::*;
+
+/// Rejects mode-specific keys even when unknown-key handling is permissive.
+pub(super) fn validate_mode_keys(document: &toml::Value) -> Result<()> {
+    if let Some(vhosts) = document
+        .get("web")
+        .and_then(|web| web.get("vhosts"))
+        .and_then(toml::Value::as_array)
+    {
+        for (idx, vhost) in vhosts.iter().enumerate() {
+            if let Some(decoy) = vhost.get("decoy")
+                && decoy.get("resolve").is_some()
+                && decoy.get("mode").and_then(toml::Value::as_str) != Some("http_upstream")
+            {
+                return Err(ProxyError::Config(format!(
+                    "web.vhosts[{idx}].decoy.resolve is only valid for mode=http_upstream"
+                )));
+            }
+        }
+    }
+    Ok(())
+}
+
+/// Parses one origin and preserves the existing literal-address containment policy.
+pub(super) fn parse_origin(
+    idx: usize,
+    upstream: &str,
+    resolve: WebDecoyResolve,
+) -> Result<url::Url> {
+    let parsed = url::Url::parse(upstream).map_err(|error| {
+        ProxyError::Config(format!(
+            "web.vhosts[{idx}].decoy.upstream is invalid: {error}"
+        ))
+    })?;
+    if parsed.scheme() != "http"
+        || parsed.host_str().is_none()
+        || !parsed.username().is_empty()
+        || parsed.password().is_some()
+        || parsed.query().is_some()
+        || parsed.fragment().is_some()
+        || parsed.path() != "/"
+        || parsed.port() == Some(0)
+    {
+        return Err(ProxyError::Config(format!(
+            "web.vhosts[{idx}].decoy.upstream must be an http origin without credentials, path, query, or fragment"
+        )));
+    }
+    match parsed.host() {
+        Some(url::Host::Ipv4(ip)) => validate_address(idx, IpAddr::V4(ip))?,
+        Some(url::Host::Ipv6(ip)) => validate_address(idx, IpAddr::V6(ip))?,
+        Some(url::Host::Domain(_)) if resolve == WebDecoyResolve::Startup => {}
+        _ => {
+            return Err(ProxyError::Config(format!(
+                "web.vhosts[{idx}].decoy.upstream host must be a loopback or private IP literal unless resolve = \"startup\""
+            )));
+        }
+    }
+    Ok(parsed)
+}
+
+fn validate_address(idx: usize, ip: IpAddr) -> Result<()> {
+    let private = match ip {
+        IpAddr::V4(ip) => ip.is_loopback() || ip.is_private() || ip.is_link_local(),
+        IpAddr::V6(ip) => ip.is_loopback() || ip.is_unique_local() || ip.is_unicast_link_local(),
+    };
+    if !private {
+        return Err(ProxyError::Config(format!(
+            "web.vhosts[{idx}].decoy.upstream must remain inside loopback or a private network"
+        )));
+    }
+    Ok(())
+}
+
+/// Returns all captured answers so non-selected addresses cannot hide a listener loop.
+pub(super) fn addresses(
+    config: &ProxyConfig,
+    idx: usize,
+    parsed: &url::Url,
+    require_resolved: bool,
+) -> Result<Vec<SocketAddr>> {
+    let port = parsed
+        .port_or_known_default()
+        .ok_or_else(|| ProxyError::Config("WEB decoy port cannot be resolved".to_string()))?;
+    let answers = match parsed.host() {
+        Some(url::Host::Ipv4(ip)) => vec![SocketAddr::new(IpAddr::V4(ip), port)],
+        Some(url::Host::Ipv6(ip)) => vec![SocketAddr::new(IpAddr::V6(ip), port)],
+        Some(url::Host::Domain(host)) => {
+            let key = (host.to_string(), port);
+            match config.web.decoy_dns.origins.get(&key) {
+                Some(answers) if !answers.is_empty() => answers.clone(),
+                _ if !require_resolved => return Ok(Vec::new()),
+                _ => {
+                    return Err(ProxyError::Config(format!(
+                        "web.vhosts[{idx}].decoy.upstream requires async preparation for resolve = \"startup\""
+                    )));
+                }
+            }
+        }
+        _ => return Err(ProxyError::Config("WEB decoy host is missing".to_string())),
+    };
+    for addr in &answers {
+        validate_address(idx, addr.ip())?;
+        if addr.port() != port {
+            return Err(ProxyError::Config(
+                "WEB decoy DNS snapshot port mismatch".to_string(),
+            ));
+        }
+    }
+    Ok(answers)
+}
+
+/// Captures fresh resolver evidence without publishing any partially prepared configuration.
+pub(super) async fn prepare<F, Fut>(config: &mut ProxyConfig, mut lookup: F) -> Result<()>
+where
+    F: FnMut(String, u16) -> Fut,
+    Fut: Future<Output = std::io::Result<Vec<SocketAddr>>>,
+{
+    let mut snapshot = WebDecoyDnsSnapshot::default();
+    for (idx, vhost) in config.web.vhosts.iter().enumerate() {
+        let WebDecoyConfig::HttpUpstream { upstream, resolve } = &vhost.decoy else {
+            continue;
+        };
+        let parsed = parse_origin(idx, upstream, *resolve)?;
+        let Some(url::Host::Domain(host)) = parsed.host() else {
+            continue;
+        };
+        let port = parsed
+            .port_or_known_default()
+            .ok_or_else(|| ProxyError::Config("WEB decoy port cannot be resolved".to_string()))?;
+        let key = (host.to_string(), port);
+        if snapshot.origins.contains_key(&key) {
+            continue;
+        }
+        // Dropping this wait does not forcibly cancel a running OS resolver call.
+        let answers = tokio::time::timeout(
+            Duration::from_secs(config.web.timeouts.decoy_resolve_secs),
+            lookup(key.0.clone(), port),
+        )
+        .await
+        .map_err(|_| {
+            ProxyError::Config(format!(
+                "web.vhosts[{idx}].decoy.upstream DNS resolution timed out after {} seconds",
+                config.web.timeouts.decoy_resolve_secs
+            ))
+        })?
+        .map_err(|error| {
+            ProxyError::Config(format!(
+                "web.vhosts[{idx}].decoy.upstream DNS resolution failed: {error}"
+            ))
+        })?;
+        if answers.is_empty() {
+            return Err(ProxyError::Config(format!(
+                "web.vhosts[{idx}].decoy.upstream DNS resolution returned no addresses"
+            )));
+        }
+        for addr in &answers {
+            validate_address(idx, addr.ip())?;
+        }
+        snapshot.origins.insert(key, answers);
+    }
+    config.web.decoy_dns = Arc::new(snapshot);
+    validate_web::validate_decoy_listener_separation(config)
+}
+
+/// Builds the unchanged request-time tuple from immutable configuration evidence.
+pub(super) fn build_upstream(
+    config: &ProxyConfig,
+    idx: usize,
+    upstream: &str,
+    resolve: WebDecoyResolve,
+) -> Result<WebRuntimeDecoy> {
+    let parsed = parse_origin(idx, upstream, resolve)?;
+    let addr = addresses(config, idx, &parsed, true)?
+        .first()
+        .copied()
+        .ok_or_else(|| ProxyError::Config("WEB decoy DNS snapshot is empty".to_string()))?;
+    // URL authority keeps the configured hostname and brackets IPv6 literals.
+    let authority = parsed[url::Position::BeforeHost..url::Position::AfterPort].to_string();
+    Ok(WebRuntimeDecoy::HttpUpstream { addr, authority })
+}
+
+impl ProxyConfig {
+    /// Compares selected endpoints separately from source-only configuration equality.
+    pub(crate) fn web_decoy_endpoints_equal(&self, other: &Self) -> bool {
+        fn selected(config: &ProxyConfig) -> impl Iterator<Item = (&String, SocketAddr)> {
+            config
+                .web
+                .runtime
+                .iter()
+                .flat_map(|runtime| runtime.vhosts.iter())
+                .filter_map(|(host, vhost)| match vhost.decoy {
+                    WebRuntimeDecoy::HttpUpstream { addr, .. } => Some((host, addr)),
+                    WebRuntimeDecoy::StaticDirectory(_) => None,
+                })
+        }
+        selected(self).eq(selected(other))
+    }
+}
+
+#[cfg(test)]
+mod tests;

src/config/load/decoy_dns/tests.rs

@@ -0,0 +1,330 @@
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+use super::*;
+
+const SOURCE: &str = r#"
+[access.users]
+alice = "000102030405060708090a0b0c0d0e0f"
+[[server.listeners]]
+ip = "127.0.0.1"
+port = 18080
+transport = "web"
+web_trusted_proxy_cidrs = ["127.0.0.1/32"]
+[web]
+enabled = true
+[[web.vhosts]]
+host = "proxy.example.com"
+public_addr = "203.0.113.10:443"
+[web.vhosts.decoy]
+mode = "http_upstream"
+upstream = "http://Example.COM:18081"
+resolve = "startup"
+[[web.vhosts.profiles]]
+user = "alice"
+secret_mode = "dd"
+"#;
+
+fn source(text: &str) -> ParsedConfigSource {
+    pipeline::parse_source_graph(ConfigSourceGraph {
+        rendered: text.to_string(),
+        source_contents: BTreeMap::new(),
+    })
+    .unwrap()
+}
+
+async fn prepared(answers: &[&str]) -> LoadedConfig {
+    let mut parsed = source(SOURCE);
+    let answers: Vec<SocketAddr> = answers.iter().map(|addr| addr.parse().unwrap()).collect();
+    prepare(&mut parsed.config, |_, _| {
+        std::future::ready(Ok(answers.clone()))
+    })
+    .await
+    .unwrap();
+    pipeline::finish(parsed).unwrap()
+}
+
+fn endpoint(config: &ProxyConfig) -> (SocketAddr, &str) {
+    let runtime = config.web.runtime.as_ref().unwrap();
+    match &runtime.vhosts["proxy.example.com"].decoy {
+        WebRuntimeDecoy::HttpUpstream { addr, authority } => (*addr, authority),
+        _ => panic!("expected HTTP decoy"),
+    }
+}
+
+#[tokio::test]
+async fn decoy_dns_snapshot_deduplicates_normalized_origins_and_preserves_order() {
+    let mut parsed = source(SOURCE);
+    let mut second = parsed.config.web.vhosts[0].clone();
+    second.host = "bsi.bund.de".to_string();
+    second.decoy = WebDecoyConfig::HttpUpstream {
+        upstream: "http://example.com:18081/".to_string(),
+        resolve: WebDecoyResolve::Startup,
+    };
+    parsed.config.web.vhosts.push(second);
+    let calls = AtomicUsize::new(0);
+    prepare(&mut parsed.config, |host, port| {
+        assert_eq!((host.as_str(), port), ("example.com", 18081));
+        calls.fetch_add(1, Ordering::SeqCst);
+        std::future::ready(Ok(vec![
+            "[fd00::2]:18081".parse().unwrap(),
+            "10.0.0.2:18081".parse().unwrap(),
+        ]))
+    })
+    .await
+    .unwrap();
+    let mut loaded = pipeline::finish(parsed).unwrap();
+    for _ in 0..3 {
+        loaded.config.validate_effective_web().unwrap();
+        loaded.config.rebuild_runtime_web().unwrap();
+    }
+    assert_eq!(calls.load(Ordering::SeqCst), 1);
+    assert_eq!(
+        endpoint(&loaded.config),
+        ("[fd00::2]:18081".parse().unwrap(), "example.com:18081")
+    );
+    assert_eq!(
+        loaded
+            .config
+            .web
+            .decoy_dns
+            .origins
+            .values()
+            .next()
+            .unwrap()
+            .len(),
+        2
+    );
+    assert!(
+        !serde_json::to_string(&loaded.config)
+            .unwrap()
+            .contains("fd00::2")
+    );
+}
+
+#[tokio::test]
+async fn decoy_dns_rejects_every_public_answer_including_non_selected() {
+    for disallowed in [
+        "8.8.8.8:18081",
+        "[2001:4860:4860::8888]:18081",
+        "[::ffff:127.0.0.1]:18081",
+    ] {
+        let mut parsed = source(SOURCE);
+        let error = prepare(&mut parsed.config, |_, _| {
+            std::future::ready(Ok(vec![
+                "127.0.0.2:18081".parse().unwrap(),
+                disallowed.parse().unwrap(),
+            ]))
+        })
+        .await
+        .unwrap_err();
+        assert!(error.to_string().contains("must remain inside"));
+        assert!(parsed.config.web.runtime.is_none());
+    }
+}
+
+#[tokio::test]
+async fn decoy_dns_rejects_non_selected_direct_and_wildcard_listener_loops() {
+    for listener in ["127.0.0.1", "0.0.0.0"] {
+        let mut parsed = source(&SOURCE.replace("Example.COM:18081", "example.com:18080"));
+        parsed.config.server.listeners[0].ip = listener.parse().unwrap();
+        let error = prepare(&mut parsed.config, |_, _| {
+            std::future::ready(Ok(vec![
+                "[fd00::2]:18080".parse().unwrap(),
+                "127.0.0.1:18080".parse().unwrap(),
+            ]))
+        })
+        .await
+        .unwrap_err();
+        assert!(error.to_string().contains("overlaps WEB listener"));
+    }
+}
+
+#[tokio::test]
+async fn decoy_dns_empty_answers_and_resolver_errors_fail_closed() {
+    let mut parsed = source(SOURCE);
+    let error = prepare(&mut parsed.config, |_, _| {
+        std::future::ready(Ok(Vec::new()))
+    })
+    .await
+    .unwrap_err();
+    assert!(error.to_string().contains("returned no addresses"));
+    let error = prepare(&mut parsed.config, |_, _| {
+        std::future::ready(Err(std::io::Error::new(
+            std::io::ErrorKind::NotFound,
+            "test resolver failure",
+        )))
+    })
+    .await
+    .unwrap_err();
+    assert!(error.to_string().contains("DNS resolution failed"));
+}
+
+#[tokio::test]
+async fn decoy_dns_timeout_is_bounded() {
+    let mut parsed = source(SOURCE);
+    parsed.config.web.timeouts.decoy_resolve_secs = 1;
+    let error = tokio::time::timeout(
+        Duration::from_secs(3),
+        prepare(&mut parsed.config, |_, _| {
+            std::future::pending::<std::io::Result<Vec<SocketAddr>>>()
+        }),
+    )
+    .await
+    .unwrap()
+    .unwrap_err();
+    assert!(error.to_string().contains("timed out after 1 seconds"));
+}
+
+#[tokio::test]
+async fn decoy_dns_literal_startup_never_looks_up_and_keeps_ipv6_authority() {
+    let mut parsed = source(&SOURCE.replace("Example.COM:18081", "[::1]:18081"));
+    prepare(&mut parsed.config, |_, _| {
+        std::future::ready(Err(std::io::Error::other("IP literals must not reach DNS")))
+    })
+    .await
+    .unwrap();
+    let loaded = pipeline::finish(parsed).unwrap();
+    assert_eq!(
+        endpoint(&loaded.config),
+        ("[::1]:18081".parse().unwrap(), "[::1]:18081")
+    );
+}
+
+#[test]
+fn decoy_dns_source_parse_is_not_a_prepared_runtime() {
+    let parsed = source(SOURCE);
+    assert!(parsed.config.web.runtime.is_none());
+    assert!(parsed.config.web.decoy_dns.origins.is_empty());
+    assert!(
+        pipeline::finish(parsed)
+            .unwrap_err()
+            .to_string()
+            .contains("requires async preparation")
+    );
+}
+
+#[tokio::test]
+async fn decoy_dns_evidence_is_bound_to_origin_and_port() {
+    let loaded = prepared(&["10.0.0.2:18081"]).await;
+    for changed in ["http://telekom.com:18081", "http://example.com:18082"] {
+        let mut config = loaded.config.clone();
+        config.web.vhosts[0].decoy = WebDecoyConfig::HttpUpstream {
+            upstream: changed.to_string(),
+            resolve: WebDecoyResolve::Startup,
+        };
+        assert!(
+            config
+                .validate_effective_web()
+                .unwrap_err()
+                .to_string()
+                .contains("requires async preparation")
+        );
+        assert!(config.rebuild_runtime_web().is_err());
+    }
+}
+
+#[tokio::test]
+async fn decoy_dns_reload_pins_old_generation_and_detects_dns_only_changes() {
+    let old = prepared(&["10.0.0.2:18081"]).await;
+    let new = prepared(&["10.0.0.3:18081"]).await;
+    assert_eq!(old.rendered_hash, new.rendered_hash);
+    assert_eq!(
+        serde_json::to_value(&old.config).unwrap(),
+        serde_json::to_value(&new.config).unwrap()
+    );
+    let resolved =
+        crate::maestro::runtime_build::resolve_reload_config(&old.config, &new.config).unwrap();
+    assert!(resolved.runtime_changed);
+    assert!(!old.config.web_decoy_endpoints_equal(&new.config));
+    assert_eq!(endpoint(&old.config).0, "10.0.0.2:18081".parse().unwrap());
+    let same = prepared(&["10.0.0.3:18081", "10.0.0.4:18081"]).await;
+    assert!(same.config.web_decoy_endpoints_equal(&new.config));
+}
+
+#[tokio::test]
+async fn decoy_dns_effective_listener_overlay_rechecks_every_answer() {
+    let old = prepared(&["10.0.0.2:18081"]).await;
+    let mut parsed = source(SOURCE);
+    parsed.config.server.listeners[0].port = Some(18082);
+    parsed.config.web.vhosts[0].decoy = WebDecoyConfig::HttpUpstream {
+        upstream: "http://example.com:18080".to_string(),
+        resolve: WebDecoyResolve::Startup,
+    };
+    prepare(&mut parsed.config, |_, _| {
+        std::future::ready(Ok(vec![
+            "10.0.0.2:18080".parse().unwrap(),
+            "127.0.0.1:18080".parse().unwrap(),
+        ]))
+    })
+    .await
+    .unwrap();
+    let desired = pipeline::finish(parsed).unwrap();
+    assert!(
+        crate::maestro::runtime_build::resolve_reload_config(&old.config, &desired.config)
+            .err()
+            .unwrap()
+            .contains("overlaps WEB listener")
+    );
+}
+
+#[tokio::test]
+async fn decoy_dns_rejects_ipv6_direct_and_wildcard_listener_loops() {
+    for listener in ["::1", "::"] {
+        let mut parsed = source(&SOURCE.replace("Example.COM:18081", "example.com:18080"));
+        parsed.config.network.ipv6 = Some(true);
+        parsed.config.server.listeners[0].ip = listener.parse().unwrap();
+        let error = prepare(&mut parsed.config, |_, _| {
+            std::future::ready(Ok(vec![
+                "10.0.0.2:18080".parse().unwrap(),
+                "[::1]:18080".parse().unwrap(),
+            ]))
+        })
+        .await
+        .unwrap_err();
+        assert!(error.to_string().contains("overlaps WEB listener"));
+    }
+}
+
+#[test]
+fn decoy_dns_startup_does_not_relax_origin_url_rules() {
+    for url in [
+        "https://example.com",
+        "http://user@example.com",
+        "http://user:pass@example.com",
+        "http://example.com/path",
+        "http://example.com/?q=1",
+        "http://example.com/#fragment",
+        "http://example.com:0",
+    ] {
+        assert!(
+            parse_origin(0, url, WebDecoyResolve::Startup).is_err(),
+            "accepted {url}"
+        );
+    }
+}
+
+#[tokio::test]
+async fn decoy_dns_default_port_authority_and_evidence_port_fence() {
+    let mut parsed = source(&SOURCE.replace("Example.COM:18081", "example.com"));
+    prepare(&mut parsed.config, |_, port| {
+        assert_eq!(port, 80);
+        std::future::ready(Ok(vec!["127.0.0.2:80".parse().unwrap()]))
+    })
+    .await
+    .unwrap();
+    let loaded = pipeline::finish(parsed).unwrap();
+    assert_eq!(endpoint(&loaded.config).1, "example.com");
+    let mut config = loaded.config.clone();
+    Arc::make_mut(&mut config.web.decoy_dns).origins.insert(
+        ("example.com".to_string(), 80),
+        vec!["127.0.0.2:81".parse().unwrap()],
+    );
+    assert!(
+        config
+            .validate_effective_web()
+            .unwrap_err()
+            .to_string()
+            .contains("port mismatch")
+    );
+    assert!(config.rebuild_runtime_web().is_err());
+}

src/config/load/effective.rs

@@ -1,5 +1,6 @@
 use super::*;
 
+/// Normalizes source policy and authentication data before external decoy preparation.
 pub(super) fn apply(config: &mut ProxyConfig) -> Result<()> {
     // Normalize optional TLS fetch scope: whitespace-only values disable scoped routing.
     config.censorship.tls_fetch_scope = config.censorship.tls_fetch_scope.trim().to_string();
@@ -217,6 +218,5 @@ pub(super) fn apply(config: &mut ProxyConfig) -> Result<()> {
     validate_logging_config(&config.logging)?;
     validate_upstreams(config)?;
     config.rebuild_runtime_user_auth()?;
-    config.rebuild_runtime_web()?;
     Ok(())
 }

src/config/load/pipeline.rs

@@ -1,18 +1,51 @@
 use super::*;
 
+/// Completes legacy synchronous loads without performing hostname resolution.
 pub(super) fn load_source_graph(graph: ConfigSourceGraph) -> Result<LoadedConfig> {
+    finish(parse_source_graph(graph)?)
+}
+
+/// Normalizes source while leaving DNS and immutable site acquisition to preparation.
+pub(super) fn parse_source_graph(graph: ConfigSourceGraph) -> Result<ParsedConfigSource> {
     let (mut config, source_files, source_contents, processed) =
         decode::decode_source_graph(graph)?;
     validate_core::validate(&mut config)?;
     validate_runtime::validate(&mut config)?;
     validate_me::validate(&mut config)?;
     validate_server::validate(&mut config)?;
-    validate_web::validate(&mut config)?;
+    validate_web::validate_source(&mut config)?;
     effective::apply(&mut config)?;
-    Ok(LoadedConfig {
+    Ok(ParsedConfigSource {
         config,
         source_files: source_files.into_iter().collect(),
         source_contents,
         rendered_hash: hash_rendered_snapshot(&processed),
     })
 }
+
+/// Completes synchronous validation and static acquisition after DNS is captured.
+pub(super) fn finish(mut parsed: ParsedConfigSource) -> Result<LoadedConfig> {
+    parsed.config.validate_effective_web()?;
+    parsed.config.rebuild_runtime_web()?;
+    Ok(LoadedConfig {
+        config: parsed.config,
+        source_files: parsed.source_files,
+        source_contents: parsed.source_contents,
+        rendered_hash: parsed.rendered_hash,
+    })
+}
+
+impl ParsedConfigSource {
+    /// Resolves each unique decoy origin once, then builds a fully validated candidate.
+    pub(crate) async fn prepare(mut self) -> Result<LoadedConfig> {
+        decoy_dns::prepare(&mut self.config, |host, port| async move {
+            tokio::net::lookup_host((host.as_str(), port))
+                .await
+                .map(|answers| answers.collect())
+        })
+        .await?;
+        tokio::task::spawn_blocking(move || finish(self))
+            .await
+            .map_err(|error| ProxyError::Config(format!("config preparation failed: {error}")))?
+    }
+}

src/config/load/runtime_web.rs

@@ -47,8 +47,10 @@ pub(super) fn rebuild(config: &mut ProxyConfig) -> Result<()> {
     let mut static_bytes = 0usize;
 
     let carrier_candidates: Arc<[WebCarrier]> = config.web.carrier_candidates().into();
-    for vhost in &config.web.vhosts {
+    for (vhost_idx, vhost) in config.web.vhosts.iter().enumerate() {
         let decoy = build_decoy(
+            config,
+            vhost_idx,
             vhost,
             &config.web.limits,
             &mut static_files,
@@ -182,42 +184,16 @@ fn client_secret(secret: [u8; 16], mode: WebSecretMode) -> ([u8; 17], usize) {
 }
 
 fn build_decoy(
+    config: &ProxyConfig,
+    vhost_idx: usize,
     vhost: &WebVhostConfig,
     limits: &WebLimitsConfig,
     static_files: &mut usize,
     static_bytes: &mut usize,
 ) -> Result<WebRuntimeDecoy> {
     match &vhost.decoy {
-        WebDecoyConfig::HttpUpstream { upstream } => {
-            let parsed = url::Url::parse(upstream).map_err(|error| {
-                ProxyError::Config(format!(
-                    "WEB decoy upstream for `{}` is invalid: {error}",
-                    vhost.host
-                ))
-            })?;
-            let ip = match parsed.host() {
-                Some(url::Host::Ipv4(ip)) => std::net::IpAddr::V4(ip),
-                Some(url::Host::Ipv6(ip)) => std::net::IpAddr::V6(ip),
-                _ => {
-                    return Err(ProxyError::Config(
-                        "WEB decoy host must be an IP literal".to_string(),
-                    ));
-                }
-            };
-            let host = ip.to_string();
-            let port = parsed.port_or_known_default().ok_or_else(|| {
-                ProxyError::Config("WEB decoy port cannot be resolved".to_string())
-            })?;
-            let authority = match (ip, parsed.port()) {
-                (std::net::IpAddr::V6(_), Some(_)) => format!("[{host}]:{port}"),
-                (std::net::IpAddr::V6(_), None) => format!("[{host}]"),
-                (std::net::IpAddr::V4(_), Some(_)) => format!("{host}:{port}"),
-                (std::net::IpAddr::V4(_), None) => host.clone(),
-            };
-            Ok(WebRuntimeDecoy::HttpUpstream {
-                addr: SocketAddr::new(ip, port),
-                authority,
-            })
+        WebDecoyConfig::HttpUpstream { upstream, resolve } => {
+            decoy_dns::build_upstream(config, vhost_idx, upstream, *resolve)
         }
         WebDecoyConfig::StaticDirectory { directory, index } => {
             let site = load_static_site(directory, index, limits, static_files, static_bytes)?;

src/config/load/strict_keys.rs

@@ -365,10 +365,11 @@ const WEB_TIMEOUTS_CONFIG_KEYS: &[&str] = &[
     "http_overload_timeout_ms",
     "shutdown_secs",
     "decoy_header_secs",
+    "decoy_resolve_secs",
 ];
 
 const WEB_VHOST_CONFIG_KEYS: &[&str] = &["host", "base_path", "public_addr", "decoy", "profiles"];
-const WEB_DECOY_CONFIG_KEYS: &[&str] = &["mode", "upstream", "directory", "index"];
+const WEB_DECOY_CONFIG_KEYS: &[&str] = &["mode", "upstream", "directory", "index", "resolve"];
 const WEB_PROFILE_CONFIG_KEYS: &[&str] = &[
     "user",
     "secret_mode",

src/config/load/validate_web.rs

@@ -27,6 +27,12 @@ const MAX_WEB_MEMORY_ENVELOPE_BYTES: usize = 4 * 1024 * 1024 * 1024;
 
 /// Validates WEB policy and resource bounds before building runtime state.
 pub(super) fn validate(config: &mut ProxyConfig) -> Result<()> {
+    validate_source(config)?;
+    validate_decoy_listener_separation(config)
+}
+
+/// Validates source policy without requiring DNS evidence for opted-in origins.
+pub(super) fn validate_source(config: &mut ProxyConfig) -> Result<()> {
     let web_listener_count = config
         .server
         .listeners
@@ -83,12 +89,19 @@ pub(super) fn validate(config: &mut ProxyConfig) -> Result<()> {
     timeouts::validate(&config.web.timeouts)?;
     websocket::validate(&carriers, &config.web.limits, &config.web.timeouts)?;
     validate_vhosts(config)?;
-    validate_decoy_listener_separation(config)?;
+    validate_decoy_listener_separation_inner(config, false)?;
     Ok(())
 }
 
 /// Rejects a direct decoy recursion into an effective WEB listener.
 pub(super) fn validate_decoy_listener_separation(config: &ProxyConfig) -> Result<()> {
+    validate_decoy_listener_separation_inner(config, true)
+}
+
+fn validate_decoy_listener_separation_inner(
+    config: &ProxyConfig,
+    require_resolved: bool,
+) -> Result<()> {
     let web_listeners = config
         .server
         .listeners
@@ -101,30 +114,19 @@ pub(super) fn validate_decoy_listener_separation(config: &ProxyConfig) -> Result
         .map(|listener| SocketAddr::new(listener.ip, listener.port.unwrap_or(config.server.port)))
         .collect::<Vec<_>>();
     for (vhost_idx, vhost) in config.web.vhosts.iter().enumerate() {
-        let WebDecoyConfig::HttpUpstream { upstream } = &vhost.decoy else {
+        let WebDecoyConfig::HttpUpstream { upstream, resolve } = &vhost.decoy else {
             continue;
         };
-        let parsed = url::Url::parse(upstream).map_err(|error| {
-            ProxyError::Config(format!(
-                "web.vhosts[{vhost_idx}].decoy.upstream is invalid: {error}"
-            ))
-        })?;
-        let Some(port) = parsed.port_or_known_default() else {
-            continue;
-        };
-        let upstream_ip = match parsed.host() {
-            Some(url::Host::Ipv4(ip)) => IpAddr::V4(ip),
-            Some(url::Host::Ipv6(ip)) => IpAddr::V6(ip),
-            _ => continue,
-        };
-        let upstream_addr = SocketAddr::new(upstream_ip, port);
-        if web_listeners
-            .iter()
-            .any(|listener| listener_covers(*listener, upstream_addr))
-        {
-            return config_error(&format!(
-                "web.vhosts[{vhost_idx}].decoy upstream overlaps WEB listener {upstream_addr}"
-            ));
+        let parsed = decoy_dns::parse_origin(vhost_idx, upstream, *resolve)?;
+        for upstream_addr in decoy_dns::addresses(config, vhost_idx, &parsed, require_resolved)? {
+            if web_listeners
+                .iter()
+                .any(|listener| listener_covers(*listener, upstream_addr))
+            {
+                return config_error(&format!(
+                    "web.vhosts[{vhost_idx}].decoy upstream overlaps WEB listener {upstream_addr}"
+                ));
+            }
         }
     }
     Ok(())

src/config/load/validate_web/timeouts.rs

@@ -26,6 +26,7 @@ pub(super) fn validate(timeouts: &WebTimeoutsConfig) -> Result<()> {
         ("http_idle_secs", timeouts.http_idle_secs),
         ("shutdown_secs", timeouts.shutdown_secs),
         ("decoy_header_secs", timeouts.decoy_header_secs),
+        ("decoy_resolve_secs", timeouts.decoy_resolve_secs),
     ];
     if let Some((field, _)) = values
         .into_iter()

src/config/load/validate_web/vhosts.rs

@@ -150,45 +150,8 @@ pub(super) fn web_host_last_label_is_numeric(host: &str) -> bool {
 
 pub(super) fn validate_decoy(vhost_idx: usize, decoy: &WebDecoyConfig) -> Result<()> {
     match decoy {
-        WebDecoyConfig::HttpUpstream { upstream } => {
-            let parsed = url::Url::parse(upstream).map_err(|error| {
-                ProxyError::Config(format!(
-                    "web.vhosts[{vhost_idx}].decoy.upstream is invalid: {error}"
-                ))
-            })?;
-            if parsed.scheme() != "http"
-                || parsed.host_str().is_none()
-                || !parsed.username().is_empty()
-                || parsed.password().is_some()
-                || parsed.query().is_some()
-                || parsed.fragment().is_some()
-                || parsed.path() != "/"
-                || parsed.port() == Some(0)
-            {
-                return config_error(&format!(
-                    "web.vhosts[{vhost_idx}].decoy.upstream must be an http origin without credentials, path, query, or fragment"
-                ));
-            }
-            let ip = match parsed.host() {
-                Some(url::Host::Ipv4(ip)) => IpAddr::V4(ip),
-                Some(url::Host::Ipv6(ip)) => IpAddr::V6(ip),
-                _ => {
-                    return config_error(&format!(
-                        "web.vhosts[{vhost_idx}].decoy.upstream host must be a loopback or private IP literal"
-                    ));
-                }
-            };
-            let private = match ip {
-                IpAddr::V4(ip) => ip.is_loopback() || ip.is_private() || ip.is_link_local(),
-                IpAddr::V6(ip) => {
-                    ip.is_loopback() || ip.is_unique_local() || ip.is_unicast_link_local()
-                }
-            };
-            if !private {
-                return config_error(&format!(
-                    "web.vhosts[{vhost_idx}].decoy.upstream must remain inside loopback or a private network"
-                ));
-            }
+        WebDecoyConfig::HttpUpstream { upstream, resolve } => {
+            decoy_dns::parse_origin(vhost_idx, upstream, *resolve)?;
         }
         WebDecoyConfig::StaticDirectory { directory, index } => {
             if !directory.is_absolute() {

src/config/mod.rs

@@ -6,5 +6,5 @@ mod load;
 mod types;
 
 pub use load::ProxyConfig;
-pub(crate) use load::{ConfigSourceGraph, LoadedConfig};
+pub(crate) use load::{ConfigSourceGraph, LoadedConfig, ParsedConfigSource};
 pub use types::*;

src/config/tests/load_basic_tests/web_tests.rs

@@ -9,6 +9,8 @@ mod carrier_method_tests;
 
 #[path = "web_tests/conveyor_tests.rs"]
 mod conveyor_tests;
+#[path = "web_tests/decoy_dns_tests.rs"]
+mod decoy_dns_tests;
 
 const WEB_CONFIG: &str = r#"
 [access.users]

src/config/tests/load_basic_tests/web_tests/decoy_dns_tests.rs

@@ -0,0 +1,57 @@
+use super::*;
+
+#[test]
+fn decoy_dns_resolution_defaults_to_never() {
+    let decoy: WebDecoyConfig = serde_json::from_value(serde_json::json!({
+        "mode": "http_upstream",
+        "upstream": "http://127.0.0.1:18081"
+    }))
+    .unwrap();
+    let serialized = serde_json::to_value(decoy).unwrap();
+    assert_eq!(serialized["resolve"], "never");
+}
+
+#[test]
+fn decoy_dns_timeout_defaults_to_five_seconds() {
+    let serialized = serde_json::to_value(WebTimeoutsConfig::default()).unwrap();
+    assert_eq!(serialized["decoy_resolve_secs"], 5);
+}
+
+#[test]
+fn decoy_dns_resolution_is_opt_in_and_mode_specific() {
+    let hostname = WEB_CONFIG.replace("127.0.0.1:18081", "example.com:18081");
+    assert!(load_config_error_from_temp_toml(&hostname).contains("IP literal"));
+    let never = hostname.replace(
+        "mode = \"http_upstream\"",
+        "mode = \"http_upstream\"\nresolve = \"never\"",
+    );
+    assert!(load_config_error_from_temp_toml(&never).contains("IP literal"));
+    let unknown = WEB_CONFIG.replace(
+        "mode = \"http_upstream\"",
+        "mode = \"http_upstream\"\nresolve = \"always\"",
+    );
+    assert!(load_config_error_from_temp_toml(&unknown).contains("unknown variant"));
+    let wrong_mode = WEB_CONFIG.replace(
+        "mode = \"http_upstream\"",
+        "mode = \"static_directory\"\nresolve = \"startup\"\ndirectory = \"/tmp\"",
+    );
+    assert!(
+        load_config_error_from_temp_toml(&wrong_mode).contains("only valid for mode=http_upstream")
+    );
+}
+
+#[test]
+fn decoy_dns_timeout_bounds_are_independent_from_request_deadlines() {
+    for seconds in [0, 3601] {
+        let text = format!("{WEB_CONFIG}\n[web.timeouts]\ndecoy_resolve_secs = {seconds}\n");
+        assert!(load_config_error_from_temp_toml(&text).contains("decoy_resolve_secs"));
+    }
+    let text = format!("{WEB_CONFIG}\n[web.timeouts]\ndecoy_resolve_secs = 3600\n");
+    assert_eq!(
+        load_config_from_temp_toml(&text)
+            .web
+            .timeouts
+            .decoy_resolve_secs,
+        3600
+    );
+}

src/config/types.rs

@@ -54,12 +54,12 @@ pub use server::{
 #[allow(unused_imports)]
 pub use web::{
     WebCarrierNegotiationAggressiveness, WebConfig, WebDecoyConfig, WebDecoyFastTrackMode,
-    WebHttpConnectionCapacityAction, WebLimitsConfig, WebProfileConfig, WebSecretMode,
-    WebTimeoutsConfig, WebVhostConfig,
+    WebDecoyResolve, WebHttpConnectionCapacityAction, WebLimitsConfig, WebProfileConfig,
+    WebSecretMode, WebTimeoutsConfig, WebVhostConfig,
 };
 pub(crate) use web::{
-    WebRuntimeConfig, WebRuntimeDecoy, WebRuntimeProfile, WebRuntimeVhost, WebStaticAsset,
-    WebStaticSite,
+    WebDecoyDnsSnapshot, WebRuntimeConfig, WebRuntimeDecoy, WebRuntimeProfile, WebRuntimeVhost,
+    WebStaticAsset, WebStaticSite,
 };
 pub(crate) use web_carrier::WEB_CARRIER_LEARNING_MIN_ENTRIES;
 #[allow(unused_imports)]

src/config/types/web.rs

@@ -18,6 +18,10 @@ pub use fasttrack::WebDecoyFastTrackMode;
 // Accepted-socket overload policy remains separate from the bulky WEB data model.
 mod overload;
 pub use overload::WebHttpConnectionCapacityAction;
+// DNS evidence belongs to configuration generations, never request-time routing.
+mod decoy_dns;
+pub(crate) use decoy_dns::WebDecoyDnsSnapshot;
+pub use decoy_dns::WebDecoyResolve;
 
 /// Client-facing secret representation used to derive a WEB capability.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
@@ -55,6 +59,9 @@ pub enum WebDecoyConfig {
     HttpUpstream {
         /// Origin URL without a query or fragment.
         upstream: String,
+        /// Opt-in configuration-time resolution; literal addresses never require DNS.
+        #[serde(default)]
+        resolve: WebDecoyResolve,
     },
     /// Serve an immutable, bounded snapshot of a local directory.
     StaticDirectory {
@@ -358,6 +365,9 @@ pub struct WebTimeoutsConfig {
     /// Deadline for connecting to and receiving headers from an HTTP decoy.
     #[serde(default = "default_web_decoy_header_timeout_secs")]
     pub decoy_header_secs: u64,
+    /// Maximum wait for each unique HTTP decoy hostname during preparation.
+    #[serde(default = "default_web_decoy_resolve_secs")]
+    pub decoy_resolve_secs: u64,
 }
 
 impl Default for WebTimeoutsConfig {
@@ -387,6 +397,7 @@ impl Default for WebTimeoutsConfig {
             http_overload_timeout_ms: default_web_http_overload_timeout_ms(),
             shutdown_secs: default_web_shutdown_secs(),
             decoy_header_secs: default_web_decoy_header_timeout_secs(),
+            decoy_resolve_secs: default_web_decoy_resolve_secs(),
         }
     }
 }
@@ -449,6 +460,9 @@ pub struct WebConfig {
     /// Validated immutable runtime snapshot built during configuration loading.
     #[serde(skip)]
     pub(crate) runtime: Option<Arc<WebRuntimeConfig>>,
+    /// Immutable DNS evidence omitted from serialized configuration and revisions.
+    #[serde(skip)]
+    pub(crate) decoy_dns: Arc<WebDecoyDnsSnapshot>,
 }
 
 impl WebConfig {
@@ -489,6 +503,7 @@ impl Default for WebConfig {
             timeouts: WebTimeoutsConfig::default(),
             vhosts: Vec::new(),
             runtime: None,
+            decoy_dns: Arc::default(),
         }
     }
 }

src/config/types/web/decoy_dns.rs

@@ -0,0 +1,22 @@
+use std::collections::BTreeMap;
+use std::net::SocketAddr;
+
+use serde::{Deserialize, Serialize};
+
+/// Configuration-time DNS policy for an HTTP decoy origin.
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum WebDecoyResolve {
+    /// Accept IP literals only, without consulting DNS.
+    #[default]
+    Never,
+    /// Pin validated DNS answers for the lifetime of the prepared configuration.
+    Startup,
+}
+
+/// Complete resolver evidence, retained for validation against effective listeners.
+#[derive(Debug, Clone, Default)]
+pub(crate) struct WebDecoyDnsSnapshot {
+    /// Resolver-order answers keyed by canonical URL hostname and effective port.
+    pub(crate) origins: BTreeMap<(String, u16), Vec<SocketAddr>>,
+}

src/config/types/web/defaults.rs

@@ -115,3 +115,4 @@ u64_default!(default_web_http_idle_secs, 75);
 u64_default!(default_web_http_overload_timeout_ms, 250);
 u64_default!(default_web_shutdown_secs, 15);
 u64_default!(default_web_decoy_header_timeout_secs, 30);
+u64_default!(default_web_decoy_resolve_secs, 5);

src/healthcheck.rs

@@ -8,13 +8,17 @@ use crate::config::ProxyConfig;
 
 const HEALTHCHECK_RESPONSE_MAX_BYTES: u64 = 64 * 1024;
 
+/// API health contract selected by the standalone healthcheck command.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub(crate) enum HealthcheckMode {
+    /// Require a responsive API process.
     Liveness,
+    /// Require the active runtime to report readiness.
     Ready,
 }
 
 impl HealthcheckMode {
+    /// Parses the supported command-line healthcheck modes.
     pub(crate) fn from_cli_arg(value: &str) -> Option<Self> {
         match value {
             "liveness" => Some(Self::Liveness),
@@ -31,6 +35,7 @@ impl HealthcheckMode {
     }
 }
 
+/// Runs the bounded API healthcheck without preparing a new proxy generation.
 pub(crate) fn run(config_path: &str, mode: HealthcheckMode) -> i32 {
     match run_inner(config_path, mode) {
         Ok(()) => 0,
@@ -42,8 +47,9 @@ pub(crate) fn run(config_path: &str, mode: HealthcheckMode) -> i32 {
 }
 
 fn run_inner(config_path: &str, mode: HealthcheckMode) -> Result<(), String> {
-    let config =
-        ProxyConfig::load(config_path).map_err(|error| format!("config load failed: {error}"))?;
+    let config = ProxyConfig::parse_source(config_path)
+        .map_err(|error| format!("config load failed: {error}"))?
+        .config;
     let api_cfg = &config.server.api;
     if !api_cfg.enabled {
         return Ok(());
@@ -229,4 +235,26 @@ mod tests {
 
         assert!(read_response_bounded(&mut payload.as_slice()).is_err());
     }
+
+    #[test]
+    fn decoy_dns_healthcheck_reads_source_without_resolution() {
+        let directory = tempfile::tempdir().unwrap();
+        let path = directory.path().join("config.toml");
+        std::fs::write(
+            &path,
+            r#"
+[server.api]
+enabled = false
+[[web.vhosts]]
+host = "proxy.example.com"
+public_addr = "203.0.113.10:443"
+[web.vhosts.decoy]
+mode = "http_upstream"
+upstream = "http://unresolvable.example.invalid:8080"
+resolve = "startup"
+"#,
+        )
+        .unwrap();
+        super::run_inner(path.to_str().unwrap(), HealthcheckMode::Liveness).unwrap();
+    }
 }

src/maestro/bootstrap.rs

@@ -95,8 +95,8 @@ pub(super) async fn bootstrap(
         std::process::exit(1);
     }
 
-    let mut config = match ProxyConfig::load(&config_path) {
-        Ok(c) => c,
+    let mut config = match ProxyConfig::load_prepared(config_path.clone()).await {
+        Ok(loaded) => loaded.config,
         Err(e) => {
             if config_path.exists() {
                 eprintln!("[telemt] Error: {}", e);

src/maestro/runtime_build.rs

@@ -512,6 +512,7 @@ pub(crate) fn deferred_process_fields(
 
 fn configs_equal(old: &ProxyConfig, new: &ProxyConfig) -> bool {
     serde_json::to_value(old).ok() == serde_json::to_value(new).ok()
+        && old.web_decoy_endpoints_equal(new)
 }
 
 #[cfg(test)]

src/transport/middle_proxy/handshake.rs

@@ -265,7 +265,6 @@ impl MePool {
         let transport_peer_addr = stream.peer_addr().map_err(ProxyError::Io)?;
         let peer_addr = addr;
 
-        let _ = self.maybe_detect_nat_ip(local_addr.ip()).await;
         let family = if local_addr.ip().is_ipv4() {
             IpFamily::V4
         } else {
@@ -324,9 +323,34 @@ impl MePool {
             None
         };
 
-        let local_addr_nat = self.translate_our_addr_with_reflection(local_addr, reflected);
-        let peer_addr_nat =
-            SocketAddr::new(self.translate_ip_for_nat(peer_addr.ip()), peer_addr.port());
+        // Authoritative sources do not wait behind unrelated HTTP discovery. Capture once
+        // before deriving either side of the tuple so a refresh cannot mix observations.
+        let detected = if socks_bound_kdf_addr.is_some()
+            || self.nat_runtime.nat_ip_cfg.is_some()
+            || reflected.is_some()
+        {
+            self.cached_http_nat_ip()
+        } else {
+            self.maybe_detect_nat_ip(local_addr.ip()).await
+        };
+        if self.nat_runtime.nat_probe
+            && local_addr.is_ipv4()
+            && is_bogon(local_addr.ip())
+            && socks_bound_kdf_addr.is_none()
+            && self.nat_runtime.nat_ip_cfg.is_none()
+            && reflected.is_none()
+            && detected.is_none()
+        {
+            return Err(ProxyError::Io(std::io::Error::new(
+                std::io::ErrorKind::WouldBlock,
+                "ME NAT source observation is unavailable or expired",
+            )));
+        }
+        let local_addr_nat = self.translate_our_addr_with_nat(local_addr, reflected, detected);
+        let peer_addr_nat = SocketAddr::new(
+            Self::translate_ip_with_nat(peer_addr.ip(), self.nat_runtime.nat_ip_cfg.or(detected)),
+            peer_addr.port(),
+        );
         let client_addr_for_kdf = socks_bound_kdf_addr.unwrap_or(local_addr_nat);
         if let Some(upstream_info) = upstream_egress {
             record_upstream_bnd_status(

src/transport/middle_proxy/health.rs

@@ -20,6 +20,8 @@ use super::pool::{
     MeFamilyRuntimeState, RefillTargetKey, WriterContour, WriterOpenIntent, WriterRole,
 };
 use super::pool_writer::WriterReplacementPurpose;
+// Bounded cross-family coverage transfers preserve the donor's current base floor.
+mod coverage;
 
 // Bounds reconnect jitter to at most half of the current backoff.
 const JITTER_FRAC_NUM: u64 = 2;
@@ -110,6 +112,8 @@ impl Drop for ScheduledReconnects<'_> {
 
 // Periodic family health monitor orchestration.
 mod monitor;
+// Shared-family fair scheduling and independently tracked writer-operation quanta.
+mod scheduler;
 // Draining-writer deadline enforcement.
 mod drain;
 // Per-family reconnect scheduling and health state.

src/transport/middle_proxy/health/coverage.rs

@@ -0,0 +1,109 @@
+use super::*;
+use std::sync::atomic::Ordering;
+
+/// Selects globally because the Active cap is shared across DCs and address families.
+pub(super) async fn transfer_coverage(
+    pool: &Arc<MePool>,
+    rng: &Arc<SecureRandom>,
+    dc: i32,
+    endpoint: SocketAddr,
+    required: usize,
+) -> Option<bool> {
+    let capacity = pool
+        .reserve_writer_open(
+            WriterContour::Active,
+            WriterOpenIntent::Replacement,
+            dc,
+            endpoint,
+        )
+        .await?;
+    drop(capacity);
+    let authority = pool.floor_authority();
+    let endpoints = pool.endpoint_snapshot.load_full();
+    let generation = pool.current_generation();
+    let writers = pool.writers.read().await;
+    let activity = pool.registry.writer_activity_snapshot().await;
+    let mut counts = HashMap::new();
+    for writer in writers.iter() {
+        if !writer.draining.load(Ordering::Acquire)
+            && writer.generation == generation
+            && WriterContour::from_u8(writer.contour.load(Ordering::Acquire))
+                == WriterContour::Active
+            && endpoints.contains_dc_endpoint(writer.writer_dc, writer.addr)
+        {
+            *counts
+                .entry((writer.writer_dc, writer.addr.is_ipv4()))
+                .or_insert(0usize) += 1;
+        }
+    }
+    let mut candidates = Vec::new();
+    for writer in writers.iter() {
+        if writer.draining.load(Ordering::Acquire)
+            || WriterContour::from_u8(writer.contour.load(Ordering::Acquire))
+                != WriterContour::Active
+        {
+            continue;
+        }
+        let role = WriterRole::from_writer(writer);
+        let obsolete = writer.generation != generation
+            || !endpoints.contains_dc_endpoint(writer.writer_dc, writer.addr);
+        let protected = pool.required_writers_for_dc_with_floor_mode(
+            endpoints
+                .endpoints_for_dc_family(writer.writer_dc, role.family)
+                .len(),
+            false,
+        );
+        if !obsolete
+            && counts
+                .get(&(writer.writer_dc, writer.addr.is_ipv4()))
+                .copied()
+                .unwrap_or(0)
+                <= protected
+        {
+            continue;
+        }
+        let busy = activity
+            .bound_clients_by_writer
+            .get(&writer.id)
+            .copied()
+            .unwrap_or(0)
+            > 0;
+        candidates.push((busy, !obsolete, writer.created_at, writer.id, role));
+    }
+    drop(writers);
+    candidates
+        .sort_unstable_by_key(|candidate| (candidate.0, candidate.1, candidate.2, candidate.3));
+    for (busy, _, _, id, role) in candidates {
+        let reservation = if busy {
+            pool.registry
+                .try_reserve_writer_replacement_preserving_clients(id)
+                .await
+        } else {
+            pool.registry.try_reserve_writer_replacement(id).await
+        };
+        let Some(mut reservation) = reservation else {
+            continue;
+        };
+        return Some(matches!(
+            tokio::time::timeout(
+                pool.reconnect_runtime.me_one_timeout,
+                pool.replace_writer_with_generation_contour_for_dc(
+                    endpoint,
+                    rng.as_ref(),
+                    generation,
+                    WriterContour::Active,
+                    dc,
+                    role,
+                    WriterReplacementPurpose::CoverageTransfer {
+                        authority,
+                        receiver_floor: required
+                    },
+                    &mut reservation,
+                ),
+            )
+            .await,
+            Ok(Ok(()))
+        ));
+    }
+    None
+}

src/transport/middle_proxy/health/family.rs

@@ -1,449 +1,67 @@
+use super::scheduler::HealthObservation;
 use super::*;
 
-pub(super) async fn check_family(
-    family: IpFamily,
-    pool: &Arc<MePool>,
-    rng: &Arc<SecureRandom>,
-    backoff: &mut HashMap<(i32, IpFamily), u64>,
-    next_attempt: &mut HashMap<(i32, IpFamily), Instant>,
-    inflight: &mut HashMap<(i32, IpFamily), usize>,
-    outage_backoff: &mut HashMap<(i32, IpFamily), u64>,
-    outage_next_attempt: &mut HashMap<(i32, IpFamily), Instant>,
-    single_endpoint_outage: &mut HashSet<(i32, IpFamily)>,
-    shadow_rotate_deadline: &mut HashMap<(i32, IpFamily), Instant>,
-    idle_refresh_next_attempt: &mut HashMap<(i32, IpFamily), Instant>,
-    floor_warn_next_allowed: &mut HashMap<(i32, IpFamily), Instant>,
-) -> bool {
-    let enabled = match family {
-        IpFamily::V4 => pool.decision.ipv4_me,
-        IpFamily::V6 => pool.decision.ipv6_me,
+/// Takes a control-plane observation without awaiting any network operation.
+pub(super) async fn check_family(family: IpFamily, pool: &Arc<MePool>) -> HealthObservation {
+    let authority = pool.floor_authority();
+    let generation = pool.current_generation();
+    let snapshot = pool.endpoint_snapshot.load_full();
+    let enabled = if family == IpFamily::V4 {
+        pool.decision.ipv4_me
+    } else {
+        pool.decision.ipv6_me
     };
-    if !enabled {
-        return false;
-    }
-
-    let mut family_degraded = false;
-
-    let mut dc_endpoints = HashMap::<i32, Vec<SocketAddr>>::new();
-    let endpoint_snapshot = pool.endpoint_snapshot.load();
-    let endpoint_revision = endpoint_snapshot.revision;
-    let map_guard = match family {
-        IpFamily::V4 => &endpoint_snapshot.map_v4,
-        IpFamily::V6 => &endpoint_snapshot.map_v6,
+    let source = if family == IpFamily::V4 {
+        &snapshot.map_v4
+    } else {
+        &snapshot.map_v6
     };
-    for (dc, addrs) in map_guard.iter() {
-        let entry = dc_endpoints.entry(*dc).or_default();
-        for (ip, port) in addrs.iter().copied() {
-            entry.push(SocketAddr::new(ip, port));
+    let mut endpoints = HashMap::new();
+    if enabled {
+        for (dc, addresses) in source {
+            let mut addresses: Vec<_> = addresses
+                .iter()
+                .map(|(ip, port)| SocketAddr::new(*ip, *port))
+                .collect();
+            addresses.sort_unstable();
+            addresses.dedup();
+            endpoints.insert(*dc, addresses);
         }
     }
-    drop(endpoint_snapshot);
-    for endpoints in dc_endpoints.values_mut() {
-        endpoints.sort_unstable();
-        endpoints.dedup();
-    }
-    let reconnect_budget = health_reconnect_budget(pool, dc_endpoints.len());
-    let reconnect_sem = Arc::new(Semaphore::new(reconnect_budget));
-
-    if pool.floor_mode() == MeFloorMode::Static {}
-
-    let mut live_addr_counts = HashMap::<(i32, SocketAddr), usize>::new();
-    let mut live_writer_ids_by_addr = HashMap::<(i32, SocketAddr), Vec<u64>>::new();
-    let active_generation = pool.current_generation();
-    for writer in pool
-        .writers
-        .read()
-        .await
-        .iter()
-        .filter(|w| !w.draining.load(std::sync::atomic::Ordering::Relaxed))
-    {
-        if !matches!(
-            crate::transport::middle_proxy::pool::WriterContour::from_u8(
-                writer.contour.load(std::sync::atomic::Ordering::Relaxed),
-            ),
-            crate::transport::middle_proxy::pool::WriterContour::Active
-        ) {
-            continue;
-        }
-        if writer.generation != active_generation {
-            continue;
-        }
-        if !dc_endpoints
-            .get(&writer.writer_dc)
-            .is_some_and(|endpoints| endpoints.contains(&writer.addr))
+    let mut counts = HashMap::new();
+    let mut ids = HashMap::<_, Vec<_>>::new();
+    for writer in pool.writers.read().await.iter() {
+        if !writer.draining.load(std::sync::atomic::Ordering::Acquire)
+            && writer.generation == generation
+            && WriterContour::from_u8(writer.contour.load(std::sync::atomic::Ordering::Acquire))
+                == WriterContour::Active
+            && endpoints
+                .get(&writer.writer_dc)
+                .is_some_and(|addresses| addresses.contains(&writer.addr))
         {
-            continue;
+            *counts
+                .entry((writer.writer_dc, writer.addr))
+                .or_insert(0usize) += 1;
+            ids.entry((writer.writer_dc, writer.addr))
+                .or_default()
+                .push(writer.id);
         }
-        let key = (writer.writer_dc, writer.addr);
-        *live_addr_counts.entry(key).or_insert(0) += 1;
-        live_writer_ids_by_addr
-            .entry(key)
-            .or_default()
-            .push(writer.id);
     }
-    let writer_idle_since = pool.registry.writer_idle_since_snapshot().await;
-    let bound_clients_by_writer = pool
+    let idle = pool.registry.writer_idle_since_snapshot().await;
+    let bound = pool
         .registry
         .writer_activity_snapshot()
         .await
         .bound_clients_by_writer;
-    let floor_plan = build_family_floor_plan(
-        pool,
-        family,
-        &dc_endpoints,
-        &live_addr_counts,
-        &live_writer_ids_by_addr,
-        &bound_clients_by_writer,
-    )
-    .await;
-    pool.set_adaptive_floor_runtime_caps(
-        floor_plan.active_cap_configured_total,
-        floor_plan.active_cap_effective_total,
-        floor_plan.warm_cap_configured_total,
-        floor_plan.warm_cap_effective_total,
-        floor_plan.target_writers_total,
-        floor_plan.active_writers_current,
-        floor_plan.warm_writers_current,
-    );
-    let floor_targets_by_dc = Arc::new(
-        floor_plan
-            .by_dc
-            .iter()
-            .map(|(dc, entry)| (*dc, entry.target_required))
-            .collect::<HashMap<_, _>>(),
-    );
-    let live_writer_ids_by_addr = Arc::new(live_writer_ids_by_addr);
-    let writer_idle_since = Arc::new(writer_idle_since);
-    let bound_clients_by_writer = Arc::new(bound_clients_by_writer);
-    let mut reconnect_set = JoinSet::<FamilyReconnectOutcome>::new();
-    let mut scheduled_reconnects = ScheduledReconnects {
-        inflight,
-        keys: Vec::new(),
-    };
-
-    for (dc, endpoints) in dc_endpoints {
-        if endpoints.is_empty() {
-            continue;
-        }
-        let key = (dc, family);
-        let required = floor_plan
-            .by_dc
-            .get(&dc)
-            .map(|entry| entry.target_required)
-            .unwrap_or_else(|| {
-                pool.required_writers_for_dc_with_floor_mode(endpoints.len(), false)
-            });
-        let alive = endpoints
-            .iter()
-            .map(|addr| *live_addr_counts.get(&(dc, *addr)).unwrap_or(&0))
-            .sum::<usize>();
-
-        if endpoints.len() == 1 && pool.single_endpoint_outage_mode_enabled() && alive == 0 {
-            family_degraded = true;
-            if single_endpoint_outage.insert(key) {
-                pool.stats.increment_me_single_endpoint_outage_enter_total();
-                warn!(
-                    dc = %dc,
-                    ?family,
-                    required,
-                    endpoint_count = endpoints.len(),
-                    "Single-endpoint DC outage detected"
-                );
-            }
-
-            recover_single_endpoint_outage(
-                pool,
-                rng,
-                key,
-                endpoints[0],
-                required,
-                outage_backoff,
-                outage_next_attempt,
-                &reconnect_sem,
-            )
-            .await;
-            continue;
-        }
-
-        if single_endpoint_outage.remove(&key) {
-            pool.stats.increment_me_single_endpoint_outage_exit_total();
-            outage_backoff.remove(&key);
-            outage_next_attempt.remove(&key);
-            shadow_rotate_deadline.remove(&key);
-            idle_refresh_next_attempt.remove(&key);
-            info!(
-                dc = %dc,
-                ?family,
-                alive,
-                required,
-                endpoint_count = endpoints.len(),
-                "Single-endpoint DC outage recovered"
-            );
-        }
-
-        maybe_refresh_idle_writer_for_dc(
-            pool,
-            rng,
-            key,
-            dc,
-            family,
-            &endpoints,
-            alive,
-            required,
-            live_writer_ids_by_addr.as_ref(),
-            writer_idle_since.as_ref(),
-            bound_clients_by_writer.as_ref(),
-            idle_refresh_next_attempt,
-        )
-        .await;
-
-        if alive >= required {
-            maybe_rotate_single_endpoint_shadow(
-                pool,
-                rng,
-                key,
-                dc,
-                family,
-                &endpoints,
-                alive,
-                required,
-                live_writer_ids_by_addr.as_ref(),
-                bound_clients_by_writer.as_ref(),
-                shadow_rotate_deadline,
-            )
-            .await;
-            continue;
-        }
-        let missing = required - alive;
-        family_degraded = true;
-
-        let now = Instant::now();
-        if reconnect_sem.available_permits() == 0 {
-            let base_ms = pool.reconnect_runtime.me_reconnect_backoff_base.as_millis() as u64;
-            let next_ms = (*backoff.get(&key).unwrap_or(&base_ms)).max(base_ms);
-            let jitter = next_ms / JITTER_FRAC_NUM;
-            let wait = Duration::from_millis(next_ms)
-                + Duration::from_millis(rand::rng().random_range(0..=jitter.max(1)));
-            next_attempt.insert(key, now + wait);
-            debug!(
-                dc = %dc,
-                ?family,
-                alive,
-                required,
-                endpoint_count = endpoints.len(),
-                reconnect_budget,
-                "Skipping reconnect due to per-tick health reconnect budget"
-            );
-            continue;
-        }
-        if let Some(ts) = next_attempt.get(&key)
-            && now < *ts
-        {
-            continue;
-        }
-
-        let max_concurrent = pool
-            .reconnect_runtime
-            .me_reconnect_max_concurrent_per_dc
-            .max(1) as usize;
-        if scheduled_reconnects.current(&key) >= max_concurrent {
-            continue;
-        }
-        if pool
-            .has_refill_inflight_for_target(RefillTargetKey {
-                dc,
-                family,
-                generation: pool.current_generation(),
-                endpoint_revision,
-                contour: WriterContour::Active,
-            })
-            .await
-        {
-            debug!(
-                dc = %dc,
-                ?family,
-                alive,
-                required,
-                endpoint_count = endpoints.len(),
-                "Skipping health reconnect: immediate refill is already in flight for this DC group"
-            );
-            continue;
-        }
-        scheduled_reconnects.reserve(key);
-        let pool_for_reconnect = pool.clone();
-        let rng_for_reconnect = rng.clone();
-        let reconnect_sem_for_dc = reconnect_sem.clone();
-        let endpoints_for_dc = endpoints.clone();
-        let live_writer_ids_by_addr_for_dc = live_writer_ids_by_addr.clone();
-        let writer_idle_since_for_dc = writer_idle_since.clone();
-        let bound_clients_by_writer_for_dc = bound_clients_by_writer.clone();
-        let floor_targets_by_dc_for_reconnect = floor_targets_by_dc.clone();
-        let active_cap_effective_total = floor_plan.active_cap_effective_total;
-        reconnect_set.spawn(async move {
-            let mut restored = 0usize;
-            for _ in 0..missing {
-                let Ok(reconnect_permit) = reconnect_sem_for_dc.clone().try_acquire_owned() else {
-                    break;
-                };
-                let base_req = pool_for_reconnect
-                    .required_writers_for_dc_with_floor_mode(endpoints_for_dc.len(), false);
-                if pool_for_reconnect.active_contour_writer_count_total().await
-                    >= active_cap_effective_total
-                {
-                    let swapped = maybe_swap_idle_writer_for_cap(
-                        &pool_for_reconnect,
-                        &rng_for_reconnect,
-                        dc,
-                        family,
-                        &endpoints_for_dc,
-                        required,
-                        floor_targets_by_dc_for_reconnect.as_ref(),
-                        live_writer_ids_by_addr_for_dc.as_ref(),
-                        writer_idle_since_for_dc.as_ref(),
-                        bound_clients_by_writer_for_dc.as_ref(),
-                    )
-                    .await;
-                    if swapped {
-                        pool_for_reconnect
-                            .stats
-                            .increment_me_floor_swap_idle_total();
-                        restored += 1;
-                        continue;
-                    }
-
-                    if alive + restored >= base_req {
-                        pool_for_reconnect
-                            .stats
-                            .increment_me_floor_cap_block_total();
-                        pool_for_reconnect
-                            .stats
-                            .increment_me_floor_swap_idle_failed_total();
-                        debug!(
-                            dc = %dc,
-                            ?family,
-                            alive,
-                            required,
-                            active_cap_effective_total,
-                            "Adaptive floor cap reached, reconnect attempt blocked"
-                        );
-                        break;
-                    }
-                }
-                pool_for_reconnect.stats.increment_me_reconnect_attempt();
-                let intent = if alive + restored < base_req {
-                    WriterOpenIntent::Coverage
-                } else {
-                    WriterOpenIntent::Normal
-                };
-                let res = tokio::time::timeout(
-                    pool_for_reconnect.reconnect_runtime.me_one_timeout,
-                    pool_for_reconnect.connect_endpoints_round_robin_with_generation_contour(
-                        dc,
-                        &endpoints_for_dc,
-                        rng_for_reconnect.as_ref(),
-                        pool_for_reconnect.current_generation(),
-                        WriterContour::Active,
-                        intent,
-                    ),
-                )
-                .await;
-                match res {
-                    Ok(true) => {
-                        restored += 1;
-                        pool_for_reconnect.stats.increment_me_reconnect_success();
-                    }
-                    Ok(false) => {
-                        debug!(dc = %dc, ?family, "ME round-robin reconnect failed")
-                    }
-                    Err(_) => {
-                        debug!(dc = %dc, ?family, "ME reconnect timed out");
-                    }
-                }
-                drop(reconnect_permit);
-            }
-
-            FamilyReconnectOutcome {
-                key,
-                dc,
-                family,
-                required,
-                endpoint_count: endpoints_for_dc.len(),
-            }
-        });
+    let floor = build_family_floor_plan(pool, family, &endpoints, &counts, &ids, &bound).await;
+    HealthObservation {
+        authority,
+        generation,
+        floor,
+        ids,
+        idle,
+        bound,
     }
-
-    while let Some(joined) = reconnect_set.join_next().await {
-        let outcome = match joined {
-            Ok(outcome) => outcome,
-            Err(join_error) => {
-                debug!(error = %join_error, "Health reconnect task failed");
-                continue;
-            }
-        };
-        let now = Instant::now();
-        let now_alive = live_active_writers_for_dc_family(pool, outcome.dc, outcome.family).await;
-        if now_alive >= outcome.required {
-            info!(
-                dc = %outcome.dc,
-                family = ?outcome.family,
-                alive = now_alive,
-                required = outcome.required,
-                endpoint_count = outcome.endpoint_count,
-                "ME writer floor restored for DC"
-            );
-            backoff.insert(
-                outcome.key,
-                pool.reconnect_runtime.me_reconnect_backoff_base.as_millis() as u64,
-            );
-            let jitter = pool.reconnect_runtime.me_reconnect_backoff_base.as_millis() as u64
-                / JITTER_FRAC_NUM;
-            let wait = pool.reconnect_runtime.me_reconnect_backoff_base
-                + Duration::from_millis(rand::rng().random_range(0..=jitter.max(1)));
-            next_attempt.insert(outcome.key, now + wait);
-        } else {
-            let curr = *backoff
-                .get(&outcome.key)
-                .unwrap_or(&(pool.reconnect_runtime.me_reconnect_backoff_base.as_millis() as u64));
-            let next_ms = (curr.saturating_mul(2))
-                .min(pool.reconnect_runtime.me_reconnect_backoff_cap.as_millis() as u64);
-            backoff.insert(outcome.key, next_ms);
-            let jitter = next_ms / JITTER_FRAC_NUM;
-            let wait = Duration::from_millis(next_ms)
-                + Duration::from_millis(rand::rng().random_range(0..=jitter.max(1)));
-            next_attempt.insert(outcome.key, now + wait);
-            if pool.is_runtime_ready() {
-                let warn_cooldown = pool.warn_rate_limit_duration();
-                if should_emit_rate_limited_warn(
-                    floor_warn_next_allowed,
-                    outcome.key,
-                    now,
-                    warn_cooldown,
-                ) {
-                    warn!(
-                        dc = %outcome.dc,
-                        family = ?outcome.family,
-                        alive = now_alive,
-                        required = outcome.required,
-                        endpoint_count = outcome.endpoint_count,
-                        backoff_ms = next_ms,
-                        "DC writer floor is below required level, scheduled reconnect"
-                    );
-                }
-            } else {
-                info!(
-                    dc = %outcome.dc,
-                    family = ?outcome.family,
-                    alive = now_alive,
-                    required = outcome.required,
-                    endpoint_count = outcome.endpoint_count,
-                    backoff_ms = next_ms,
-                    "DC writer floor is below required level during startup, scheduled reconnect"
-                );
-            }
-        }
-    }
-
-    family_degraded
 }
 
 pub(super) fn health_reconnect_budget(pool: &Arc<MePool>, dc_groups: usize) -> usize {

src/transport/middle_proxy/health/monitor.rs

@@ -1,59 +1,293 @@
+use super::scheduler::{
+    HealthJob, HealthObservation, HealthScheduler, JobKind, JobOutcome, idle_refresh_ready, run_job,
+};
 use super::*;
 
+/// Observes family health independently of bounded, lifecycle-owned network operations.
 pub async fn me_health_monitor(pool: Arc<MePool>, rng: Arc<SecureRandom>, _min_connections: usize) {
-    let mut backoff: HashMap<(i32, IpFamily), u64> = HashMap::new();
-    let mut next_attempt: HashMap<(i32, IpFamily), Instant> = HashMap::new();
-    let mut inflight: HashMap<(i32, IpFamily), usize> = HashMap::new();
-    let mut outage_backoff: HashMap<(i32, IpFamily), u64> = HashMap::new();
-    let mut outage_next_attempt: HashMap<(i32, IpFamily), Instant> = HashMap::new();
-    let mut single_endpoint_outage: HashSet<(i32, IpFamily)> = HashSet::new();
-    let mut shadow_rotate_deadline: HashMap<(i32, IpFamily), Instant> = HashMap::new();
-    let mut idle_refresh_next_attempt: HashMap<(i32, IpFamily), Instant> = HashMap::new();
-    let mut floor_warn_next_allowed: HashMap<(i32, IpFamily), Instant> = HashMap::new();
-    let mut drain_warn_next_allowed: HashMap<u64, Instant> = HashMap::new();
-    let mut degraded_interval = true;
+    let mut scheduler = HealthScheduler::default();
+    let mut tasks = JoinSet::new();
+    let mut observations = HashMap::<IpFamily, Arc<HealthObservation>>::new();
+    let mut drain_warn_next_allowed = HashMap::new();
+    let mut observe = true;
+    let mut health_tick = true;
+    let mut next_tick = tokio::time::Instant::now();
+
     loop {
-        let interval = if degraded_interval {
-            pool.health_interval_unhealthy()
-        } else {
-            pool.health_interval_healthy()
-        };
-        tokio::time::sleep(interval).await;
-        pool.prune_closed_writers().await;
-        pool.sweep_endpoint_quarantine().await;
-        reap_draining_writers(&pool, &mut drain_warn_next_allowed).await;
-        let v4_degraded = check_family(
-            IpFamily::V4,
-            &pool,
-            &rng,
-            &mut backoff,
-            &mut next_attempt,
-            &mut inflight,
-            &mut outage_backoff,
-            &mut outage_next_attempt,
-            &mut single_endpoint_outage,
-            &mut shadow_rotate_deadline,
-            &mut idle_refresh_next_attempt,
-            &mut floor_warn_next_allowed,
-        )
-        .await;
-        let v6_degraded = check_family(
-            IpFamily::V6,
-            &pool,
-            &rng,
-            &mut backoff,
-            &mut next_attempt,
-            &mut inflight,
-            &mut outage_backoff,
-            &mut outage_next_attempt,
-            &mut single_endpoint_outage,
-            &mut shadow_rotate_deadline,
-            &mut idle_refresh_next_attempt,
-            &mut floor_warn_next_allowed,
-        )
-        .await;
-        update_family_runtime_state(&pool, IpFamily::V4, v4_degraded);
-        update_family_runtime_state(&pool, IpFamily::V6, v6_degraded);
-        degraded_interval = v4_degraded || v6_degraded;
+        if observe {
+            if health_tick {
+                pool.prune_closed_writers().await;
+                pool.sweep_endpoint_quarantine().await;
+                reap_draining_writers(&pool, &mut drain_warn_next_allowed).await;
+            }
+            let mut target_total = 0usize;
+            let mut effective_cap = 0usize;
+            let mut cap_observation = None;
+            let mut degraded = false;
+            for family in [IpFamily::V4, IpFamily::V6] {
+                let observation = Arc::new(check_family(family, &pool).await);
+                let family_degraded = observation
+                    .floor
+                    .by_dc
+                    .values()
+                    .any(|entry| entry.alive < entry.target_required);
+                if health_tick {
+                    update_family_runtime_state(&pool, family, family_degraded);
+                }
+                degraded |= family_degraded;
+                target_total += observation
+                    .floor
+                    .by_dc
+                    .values()
+                    .map(|entry| entry.target_required)
+                    .sum::<usize>();
+                effective_cap = effective_cap.max(observation.floor.active_cap_effective_total);
+                if cap_observation.is_none() {
+                    cap_observation = Some(observation.clone());
+                }
+                observations.insert(family, observation);
+            }
+            if let Some(observation) = cap_observation
+                && observations
+                    .values()
+                    .all(|other| other.authority == observation.authority)
+            {
+                let floor = &observation.floor;
+                pool.set_adaptive_floor_runtime_caps(
+                    observation.authority,
+                    floor.active_cap_configured_total,
+                    effective_cap.max(target_total),
+                    floor.warm_cap_configured_total,
+                    floor.warm_cap_effective_total,
+                    target_total,
+                    floor.active_writers_current,
+                    floor.warm_writers_current,
+                );
+            }
+            scheduler.observe(&observations);
+            for (key, state) in &mut scheduler.groups {
+                if health_tick {
+                    state.deferred = false;
+                }
+                let Some(entry) = observations
+                    .get(&key.1)
+                    .and_then(|o| o.floor.by_dc.get(&key.0))
+                else {
+                    continue;
+                };
+                let outage = entry.endpoints.len() == 1
+                    && entry.alive == 0
+                    && pool.single_endpoint_outage_mode_enabled();
+                if outage != state.outage {
+                    if outage {
+                        pool.stats.increment_me_single_endpoint_outage_enter_total();
+                        warn!(dc = key.0, family = ?key.1, required = entry.target_required,
+                            endpoint_count = entry.endpoints.len(), "Single-endpoint DC outage detected");
+                    } else {
+                        pool.stats.increment_me_single_endpoint_outage_exit_total();
+                        info!(dc = key.0, family = ?key.1, alive = entry.alive, required = entry.target_required,
+                            endpoint_count = entry.endpoints.len(), "Single-endpoint DC outage recovered");
+                    }
+                    state.outage = outage;
+                    // Outage retries and ordinary missing-floor rounds use different bounds.
+                    // A successful first writer must not inherit an outage failure delay.
+                    state.backoff_ms = 0;
+                    state.due = None;
+                    state.round_left = 0;
+                    state.round_active = false;
+                }
+                if state.round_active
+                    && (state.round_left == 0 || entry.alive >= entry.target_required)
+                {
+                    let (base, cap) = if state.outage {
+                        pool.single_endpoint_outage_backoff_bounds_ms()
+                    } else {
+                        (
+                            pool.reconnect_runtime.me_reconnect_backoff_base.as_millis() as u64,
+                            pool.reconnect_runtime.me_reconnect_backoff_cap.as_millis() as u64,
+                        )
+                    };
+                    let restored = entry.alive >= entry.target_required;
+                    state.backoff_ms = if restored {
+                        base
+                    } else {
+                        state.backoff_ms.max(base).saturating_mul(2).min(cap)
+                    };
+                    let wait = Duration::from_millis(state.backoff_ms)
+                        + Duration::from_millis(
+                            rand::rng()
+                                .random_range(0..=(state.backoff_ms / JITTER_FRAC_NUM).max(1)),
+                        );
+                    state.due = Some(Instant::now() + wait);
+                    state.round_active = false;
+                    if restored {
+                        info!(dc = key.0, family = ?key.1, alive = entry.alive, required = entry.target_required,
+                            endpoint_count = entry.endpoints.len(), "ME writer floor restored for DC");
+                    }
+                    if !restored && state.warn_due.is_none_or(|due| due <= Instant::now()) {
+                        state.warn_due = Some(Instant::now() + pool.warn_rate_limit_duration());
+                        if state.outage {
+                            warn!(dc = key.0, family = ?key.1, endpoint = %entry.endpoints[0], required = entry.target_required,
+                                backoff_ms = state.backoff_ms, "Single-endpoint outage reconnect scheduled");
+                        } else if pool.is_runtime_ready() {
+                            warn!(dc = key.0, family = ?key.1, alive = entry.alive, required = entry.target_required,
+                                endpoint_count = entry.endpoints.len(), backoff_ms = state.backoff_ms,
+                                "DC writer floor is below required level, scheduled reconnect");
+                        } else {
+                            info!(dc = key.0, family = ?key.1, alive = entry.alive, required = entry.target_required,
+                                endpoint_count = entry.endpoints.len(), backoff_ms = state.backoff_ms,
+                                "DC writer floor is below required level during startup, scheduled reconnect");
+                        }
+                    }
+                }
+            }
+            if health_tick {
+                next_tick = tokio::time::Instant::now()
+                    + if degraded {
+                        pool.health_interval_unhealthy()
+                    } else {
+                        pool.health_interval_healthy()
+                    };
+            }
+            observe = false;
+            health_tick = false;
+        }
+
+        let budget = family::health_reconnect_budget(&pool, scheduler.groups.len());
+        for _ in 0..scheduler.queue.len() {
+            if tasks.len() >= budget {
+                break;
+            }
+            let Some(key) = scheduler.queue.pop_front() else {
+                break;
+            };
+            scheduler.queue.push_back(key);
+            if scheduler.busy(key) {
+                continue;
+            }
+            let Some(observation) = observations.get(&key.1).cloned() else {
+                continue;
+            };
+            if pool.floor_authority() != observation.authority
+                || pool.current_generation() != observation.generation
+            {
+                continue;
+            }
+            let Some(entry) = observation.floor.by_dc.get(&key.0).cloned() else {
+                continue;
+            };
+            if entry.endpoints.is_empty() {
+                continue;
+            }
+            let Some(state) = scheduler.groups.get_mut(&key) else {
+                continue;
+            };
+            if state.deferred {
+                continue;
+            }
+            let now = Instant::now();
+            let recover =
+                entry.alive < entry.target_required && state.due.is_none_or(|due| due <= now);
+            let refresh = state.refresh_due.is_none_or(|due| due <= now)
+                && idle_refresh_ready(&observation, &entry);
+            let mut kind = if refresh && (!recover || state.prefer_refresh) {
+                JobKind::Refresh
+            } else if recover {
+                JobKind::Recover
+            } else if entry.alive >= entry.target_required
+                && entry.endpoints.len() == 1
+                && pool.single_endpoint_shadow_rotate_interval().is_some()
+                && state.shadow_due.is_none_or(|due| due <= now)
+            {
+                JobKind::Shadow
+            } else {
+                continue;
+            };
+            if kind == JobKind::Recover {
+                if pool
+                    .has_refill_inflight_for_target(RefillTargetKey {
+                        dc: key.0,
+                        family: key.1,
+                        generation: observation.generation,
+                        endpoint_revision: observation.authority.0,
+                        contour: WriterContour::Active,
+                    })
+                    .await
+                {
+                    continue;
+                }
+                // Preflight distinguishes capacity pressure from unreachable endpoints without
+                // retaining an opening token while a group waits in the fair queue.
+                let reservation = pool
+                    .reserve_writer_open(
+                        WriterContour::Active,
+                        WriterOpenIntent::Coverage,
+                        key.0,
+                        entry.endpoints[0],
+                    )
+                    .await;
+                if reservation.is_none() {
+                    kind = JobKind::Transfer;
+                }
+                drop(reservation);
+                if !state.round_active {
+                    state.round = state.round.wrapping_add(1);
+                    state.round_left = if state.outage {
+                        1
+                    } else {
+                        entry.target_required.saturating_sub(entry.alive)
+                    };
+                    state.round_active = true;
+                }
+                state.prefer_refresh = true;
+            } else if kind == JobKind::Refresh {
+                state.prefer_refresh = false;
+            }
+            let job = HealthJob {
+                key,
+                kind,
+                observation,
+                entry,
+                round: state.round,
+            };
+            let future = run_job(pool.clone(), rng.clone(), job.clone());
+            let Ok(tracked) = pool.lifecycle.track_producer(future) else {
+                return;
+            };
+            let id = tasks.spawn(tracked).id();
+            scheduler.owners.insert(id, job);
+        }
+
+        let now = Instant::now();
+        let deadline = scheduler
+            .groups
+            .values()
+            .flat_map(|state| [state.due, state.refresh_due, state.shadow_due])
+            .flatten()
+            .filter(|due| *due > now)
+            .min()
+            .map(tokio::time::Instant::from_std)
+            .map_or(next_tick, |due| due.min(next_tick));
+        tokio::select! {
+            joined = tasks.join_next_with_id(), if !tasks.is_empty() => {
+                let Some(joined) = joined else { continue; };
+                let (id, output) = match joined {
+                    Ok((id, output)) => (id, output),
+                    Err(error) => {
+                        debug!(error = %error, "Health writer operation failed");
+                        (error.id(), Some(JobOutcome::Completed(None)))
+                    }
+                };
+                if let Some(job) = scheduler.owners.remove(&id)
+                    && let Some(deadline) = output {
+                    scheduler.completed(&pool, job, deadline);
+                }
+                observe = true;
+            }
+            _ = tokio::time::sleep_until(deadline) => {
+                observe = true;
+                health_tick = tokio::time::Instant::now() >= next_tick;
+            }
+        }
     }
 }

src/transport/middle_proxy/health/scheduler.rs

@@ -0,0 +1,311 @@
+use super::*;
+use std::collections::VecDeque;
+use tokio::task::Id;
+#[cfg(test)]
+mod tests;
+
+/// Exact fairness and single-owner domain; DC sign remains part of the identity.
+pub(super) type Group = (i32, IpFamily);
+
+/// Immutable observation is fenced again before dispatch and when accepting completion.
+pub(super) struct HealthObservation {
+    /// Endpoint and floor-policy revisions used to derive this plan.
+    pub(super) authority: (u64, u64),
+    /// Active generation whose writers contribute coverage.
+    pub(super) generation: u64,
+    /// Family-local targets and global capacity projection.
+    pub(super) floor: FamilyFloorPlan,
+    /// Current non-draining writer IDs grouped by DC and endpoint.
+    pub(super) ids: HashMap<(i32, SocketAddr), Vec<u64>>,
+    /// Registry idle timestamps used only for refresh selection.
+    pub(super) idle: HashMap<u64, u64>,
+    /// Captured bindings; commit revalidates victim idleness when required.
+    pub(super) bound: HashMap<u64, usize>,
+}
+
+/// Mutually exclusive network work selected for one group quantum.
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub(super) enum JobKind {
+    /// Restores one missing writer through ordinary bounded admission.
+    Recover,
+    /// Restores coverage by replacing an eligible donor.
+    Transfer,
+    /// Replaces an idle writer before upstream expiry.
+    Refresh,
+    /// Applies the configured single-endpoint rotation cadence.
+    Shadow,
+}
+
+/// Resource deferral consumes no network retry budget and preserves the eligibility deadline.
+pub(super) enum JobOutcome {
+    /// Work consumed its quantum and may return a refresh or shadow deadline.
+    Completed(Option<Instant>),
+    /// Capacity or authority prevented an operation; do not charge network backoff.
+    Deferred,
+}
+
+/// Captured authority accompanies both successful results and JoinError ownership.
+#[derive(Clone)]
+pub(super) struct HealthJob {
+    /// Group holding the unique inflight slot.
+    pub(super) key: Group,
+    /// Determines which deadline or round may change on completion.
+    pub(super) kind: JobKind,
+    /// Immutable selection evidence shared by jobs from one observation.
+    pub(super) observation: Arc<HealthObservation>,
+    /// The selected group's target and endpoint candidates.
+    pub(super) entry: DcFloorPlanEntry,
+    /// Recovery round identity; refresh and shadow operations do not consume it.
+    pub(super) round: u64,
+}
+
+/// Retry and cooldown state owned exclusively by the monitor.
+#[derive(Default)]
+pub(super) struct GroupState {
+    /// Endpoint, policy and generation fence for every mutable field below.
+    pub(super) authority: Option<((u64, u64), u64)>,
+    /// Earliest recovery eligibility; resource deferral leaves it unchanged.
+    pub(super) due: Option<Instant>,
+    /// Idle-refresh cooldown independent of missing-floor recovery.
+    pub(super) refresh_due: Option<Instant>,
+    /// Single-endpoint rotation cooldown.
+    pub(super) shadow_due: Option<Instant>,
+    /// Backoff advances once per completed recovery round.
+    pub(super) backoff_ms: u64,
+    /// Remaining writer operations in the current round.
+    pub(super) round_left: usize,
+    /// Distinguishes a finalized round from one that has no operations left yet.
+    pub(super) round_active: bool,
+    /// Monotonic identity prevents late outcomes from changing a newer round.
+    pub(super) round: u64,
+    /// Alternates independently eligible refresh and recovery work.
+    pub(super) prefer_refresh: bool,
+    /// Selects the single-endpoint outage retry namespace.
+    pub(super) outage: bool,
+    /// Rate limit for missing-floor warnings.
+    pub(super) warn_due: Option<Instant>,
+    /// Resource-blocked groups wait until the next health tick.
+    pub(super) deferred: bool,
+}
+
+/// One queue and one owner table bound work across both address families.
+#[derive(Default)]
+pub(super) struct HealthScheduler {
+    /// Persistent cursor order survives observations and worker completions.
+    pub(super) queue: VecDeque<Group>,
+    /// Coalesced work and deadlines for configured groups only.
+    pub(super) groups: HashMap<Group, GroupState>,
+    /// Task IDs release group ownership even after panic or abort.
+    pub(super) owners: HashMap<Id, HealthJob>,
+}
+
+impl HealthScheduler {
+    /// Refreshes desired groups without resetting the round-robin cursor.
+    pub(super) fn observe(&mut self, observations: &HashMap<IpFamily, Arc<HealthObservation>>) {
+        let mut current = HashSet::new();
+        for (family, observation) in observations {
+            for dc in observation.floor.by_dc.keys() {
+                let key = (*dc, *family);
+                current.insert(key);
+                let state = self.groups.entry(key).or_default();
+                let authority = (observation.authority, observation.generation);
+                if state.authority != Some(authority) {
+                    *state = GroupState {
+                        authority: Some(authority),
+                        ..GroupState::default()
+                    };
+                }
+                if !self.queue.contains(&key) {
+                    self.queue.push_back(key);
+                }
+            }
+        }
+        self.queue.retain(|key| current.contains(key));
+        self.groups.retain(|key, _| current.contains(key));
+    }
+
+    /// Includes obsolete tasks until their actual completion releases ownership.
+    pub(super) fn busy(&self, key: Group) -> bool {
+        self.owners.values().any(|job| job.key == key)
+    }
+
+    /// Accepts only an authoritative outcome from a still-active recovery round.
+    pub(super) fn completed(&mut self, pool: &Arc<MePool>, job: HealthJob, outcome: JobOutcome) {
+        let Some(state) = self.groups.get_mut(&job.key) else {
+            return;
+        };
+        if state.authority != Some((job.observation.authority, job.observation.generation))
+            || pool.floor_authority() != job.observation.authority
+            || pool.current_generation() != job.observation.generation
+        {
+            return;
+        }
+        if matches!(job.kind, JobKind::Recover | JobKind::Transfer)
+            && (!state.round_active || state.round != job.round)
+        {
+            return;
+        }
+        let JobOutcome::Completed(deadline) = outcome else {
+            state.deferred = true;
+            return;
+        };
+        match job.kind {
+            JobKind::Refresh => {
+                state.refresh_due = Some(deadline.unwrap_or_else(|| {
+                    Instant::now() + Duration::from_secs(IDLE_REFRESH_RETRY_SECS)
+                }))
+            }
+            JobKind::Shadow => {
+                state.shadow_due = Some(deadline.unwrap_or_else(|| {
+                    Instant::now() + Duration::from_secs(SHADOW_ROTATE_RETRY_SECS)
+                }))
+            }
+            JobKind::Recover | JobKind::Transfer => {
+                state.round_left = state.round_left.saturating_sub(1);
+                // Round finalization uses the next fresh observation, never the job's old count.
+                state.due = None;
+            }
+        }
+    }
+}
+
+/// Finds refresh work without waiting for another group's network operation.
+pub(super) fn idle_refresh_ready(
+    observation: &HealthObservation,
+    entry: &DcFloorPlanEntry,
+) -> bool {
+    let now = MePool::now_epoch_secs();
+    entry.endpoints.iter().any(|endpoint| {
+        observation
+            .ids
+            .get(&(entry.dc, *endpoint))
+            .is_some_and(|ids| {
+                ids.iter().any(|id| {
+                    observation.bound.get(id).copied().unwrap_or(0) == 0
+                        && observation.idle.get(id).is_some_and(|since| {
+                            now.saturating_sub(*since)
+                                >= IDLE_REFRESH_TRIGGER_BASE_SECS
+                                    + id % (IDLE_REFRESH_TRIGGER_JITTER_SECS + 1)
+                        })
+                })
+            })
+    })
+}
+
+/// Executes at most one bounded writer operation, never a whole missing-writer batch.
+pub(super) async fn run_job(
+    pool: Arc<MePool>,
+    rng: Arc<SecureRandom>,
+    job: HealthJob,
+) -> JobOutcome {
+    if pool.floor_authority() != job.observation.authority
+        || pool.current_generation() != job.observation.generation
+    {
+        return JobOutcome::Deferred;
+    }
+    let key = job.key;
+    let entry = &job.entry;
+    let observation = &job.observation;
+    let mut deadlines = HashMap::new();
+    match job.kind {
+        JobKind::Refresh => {
+            maybe_refresh_idle_writer_for_dc(
+                &pool,
+                &rng,
+                key,
+                key.0,
+                key.1,
+                &entry.endpoints,
+                entry.alive,
+                entry.target_required,
+                &observation.ids,
+                &observation.idle,
+                &observation.bound,
+                &mut deadlines,
+            )
+            .await
+        }
+        JobKind::Shadow => {
+            maybe_rotate_single_endpoint_shadow(
+                &pool,
+                &rng,
+                key,
+                key.0,
+                key.1,
+                &entry.endpoints,
+                entry.alive,
+                entry.target_required,
+                &observation.ids,
+                &observation.bound,
+                &mut deadlines,
+            )
+            .await
+        }
+        JobKind::Transfer => {
+            if coverage::transfer_coverage(
+                &pool,
+                &rng,
+                key.0,
+                entry.endpoints[0],
+                entry.target_required,
+            )
+            .await
+            .is_none()
+            {
+                return JobOutcome::Deferred;
+            }
+        }
+        JobKind::Recover => {
+            let outage = entry.endpoints.len() == 1
+                && entry.alive == 0
+                && pool.single_endpoint_outage_mode_enabled();
+            pool.stats.increment_me_reconnect_attempt();
+            if outage {
+                pool.stats
+                    .increment_me_single_endpoint_outage_reconnect_attempt_total();
+            }
+            let base = pool.required_writers_for_dc_with_floor_mode(entry.endpoints.len(), false);
+            let intent = if entry.alive < base {
+                WriterOpenIntent::Coverage
+            } else {
+                WriterOpenIntent::Normal
+            };
+            let connected = tokio::time::timeout(pool.reconnect_runtime.me_one_timeout, async {
+                if outage && pool.single_endpoint_outage_disable_quarantine() {
+                    pool.stats
+                        .increment_me_single_endpoint_quarantine_bypass_total();
+                    pool.connect_one_with_generation_contour_for_dc_with_intent(
+                        entry.endpoints[0],
+                        rng.as_ref(),
+                        observation.generation,
+                        WriterContour::Active,
+                        key.0,
+                        intent,
+                    )
+                    .await
+                    .is_ok()
+                } else {
+                    pool.connect_endpoints_round_robin_with_generation_contour(
+                        key.0,
+                        &entry.endpoints,
+                        rng.as_ref(),
+                        observation.generation,
+                        WriterContour::Active,
+                        intent,
+                    )
+                    .await
+                }
+            })
+            .await
+            .unwrap_or(false);
+            if connected {
+                pool.stats.increment_me_reconnect_success();
+                if outage {
+                    pool.stats
+                        .increment_me_single_endpoint_outage_reconnect_success_total();
+                }
+            }
+        }
+    }
+    JobOutcome::Completed(deadlines.remove(&key))
+}

src/transport/middle_proxy/health/scheduler/tests.rs

@@ -0,0 +1,67 @@
+use super::*;
+use crate::transport::middle_proxy::pool_writer_security_tests::make_pool;
+
+#[tokio::test]
+async fn deferred_and_stale_completions_preserve_round_budget_and_deadlines() {
+    let pool = make_pool().await;
+    let addr: SocketAddr = "127.0.0.1:443".parse().unwrap();
+    pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+        .await;
+    let observation = Arc::new(check_family(IpFamily::V4, &pool).await);
+    let mut scheduler = HealthScheduler::default();
+    scheduler.observe(&HashMap::from([(IpFamily::V4, observation.clone())]));
+    let key = (2, IpFamily::V4);
+    let entry = observation.floor.by_dc[&2].clone();
+    let job = HealthJob {
+        key,
+        kind: JobKind::Transfer,
+        observation,
+        entry,
+        round: 4,
+    };
+    let due = Instant::now() - Duration::from_secs(1);
+    let state = scheduler.groups.get_mut(&key).unwrap();
+    state.round = 4;
+    state.round_left = 3;
+    state.round_active = true;
+    state.due = Some(due);
+    scheduler.completed(&pool, job.clone(), JobOutcome::Deferred);
+    let state = &scheduler.groups[&key];
+    assert!(state.deferred);
+    assert_eq!(state.round_left, 3);
+    assert_eq!(state.due, Some(due));
+    let state = scheduler.groups.get_mut(&key).unwrap();
+    state.deferred = false;
+    state.round_active = false;
+    scheduler.completed(&pool, job.clone(), JobOutcome::Completed(None));
+    scheduler.completed(&pool, job, JobOutcome::Deferred);
+    let state = &scheduler.groups[&key];
+    assert!(!state.deferred);
+    assert_eq!(state.round_left, 3);
+    assert_eq!(state.due, Some(due));
+}
+
+#[tokio::test]
+async fn queue_survives_repeated_observations_without_starving_later_groups() {
+    let pool = make_pool().await;
+    pool.update_proxy_maps(
+        (1..=12)
+            .map(|dc| (dc, vec![("127.0.0.1".parse().unwrap(), 443)]))
+            .collect(),
+        None,
+    )
+    .await;
+    let observation = Arc::new(check_family(IpFamily::V4, &pool).await);
+    let observations = HashMap::from([(IpFamily::V4, observation)]);
+    let mut scheduler = HealthScheduler::default();
+    scheduler.observe(&observations);
+    let expected = scheduler.queue.iter().copied().collect::<HashSet<_>>();
+    let mut visited = HashSet::new();
+    for _ in 0..expected.len() {
+        let key = scheduler.queue.pop_front().unwrap();
+        scheduler.queue.push_back(key);
+        visited.insert(key);
+        scheduler.observe(&observations);
+    }
+    assert_eq!(visited, expected);
+}

src/transport/middle_proxy/pool.rs

@@ -342,6 +342,8 @@ pub(super) struct ReinitCoordinatorState {
     /// Latest endpoint authority revision accepted by the coordinator.
     pub(super) endpoint_revision: u64,
     pub(super) pending: Option<ReinitPendingState>,
+    /// Revision of the coherent floor and capacity policy.
+    pub(super) floor_policy_revision: u64,
     pub(super) attempts: HashMap<u64, ReinitAttemptState>,
 }
 
@@ -409,7 +411,7 @@ pub(super) struct BindingPolicyCore {
 pub(super) struct NatRuntimeCore {
     pub(super) discovery: super::pool_nat::NatDiscovery,
     pub(super) nat_ip_cfg: Option<IpAddr>,
-    pub(super) nat_ip_detected: Arc<RwLock<Option<IpAddr>>>,
+    pub(super) nat_ip_detected: Arc<RwLock<Option<super::pool_nat::HttpNatObservation>>>,
     pub(super) nat_probe: bool,
     pub(super) nat_stun: Option<String>,
     pub(super) nat_stun_servers: Vec<String>,
@@ -503,10 +505,10 @@ pub struct MePool {
     pub(super) proxy_secret: Arc<RwLock<SecretSnapshot>>,
     pub(super) default_dc: AtomicI32,
     pub(super) next_writer_id: AtomicU64,
-    pub(super) writer_connect_active_reserved: AtomicUsize,
-    pub(super) writer_connect_warm_reserved: AtomicUsize,
-    /// Replacement connections opened but not yet committed to writer visibility.
-    pub(super) writer_replacement_open_reserved: AtomicUsize,
+    pub(super) writer_connect_active_reserved: Arc<AtomicUsize>,
+    pub(super) writer_connect_warm_reserved: Arc<AtomicUsize>,
+    /// Physical replacement overlap: preparation plus victims awaiting transport destruction.
+    pub(super) writer_replacement_open_reserved: Arc<AtomicUsize>,
     pub(super) rtt_stats: Arc<Mutex<HashMap<u64, (f64, f64)>>>,
     /// Coalesced refill state keyed by exact generation and contour ownership.
     pub(super) refill_states: Arc<ParkingMutex<HashMap<RefillTargetKey, RefillTargetState>>>,
@@ -545,6 +547,8 @@ mod transport_policy;
 mod selection_policy;
 // Bounded writer-open admission and coverage accounting.
 mod writer_admission;
+// Coherent policy revisions fence derived health plans and replacement decisions.
+mod floor_authority;
 pub(super) use writer_admission::{WriterOpenIntent, WriterOpenReservation, WriterRole};
 // Endpoint-to-DC routing and health timing policy.
 mod routing;

src/transport/middle_proxy/pool/construction.rs

@@ -165,6 +165,7 @@ impl MePool {
                     active_generation: 1,
                     desired_map_hash: 0,
                     endpoint_revision: 1,
+                    floor_policy_revision: 1,
                     pending: None,
                     attempts: HashMap::new(),
                 }),
@@ -395,9 +396,9 @@ impl MePool {
             pool_size: 2,
             default_dc: AtomicI32::new(default_dc.unwrap_or(2)),
             next_writer_id: AtomicU64::new(1),
-            writer_connect_active_reserved: AtomicUsize::new(0),
-            writer_connect_warm_reserved: AtomicUsize::new(0),
-            writer_replacement_open_reserved: AtomicUsize::new(0),
+            writer_connect_active_reserved: Arc::new(AtomicUsize::new(0)),
+            writer_connect_warm_reserved: Arc::new(AtomicUsize::new(0)),
+            writer_replacement_open_reserved: Arc::new(AtomicUsize::new(0)),
             rtt_stats: Arc::new(Mutex::new(HashMap::new())),
             refill_states: Arc::new(ParkingMutex::new(HashMap::new())),
             refill_running: AtomicUsize::new(0),

src/transport/middle_proxy/pool/floor_authority.rs

@@ -0,0 +1,59 @@
+use super::*;
+#[cfg(test)]
+mod tests;
+
+impl MePool {
+    /// Captures the two independent authorities used by a health plan.
+    pub(in crate::transport::middle_proxy) fn floor_authority(&self) -> (u64, u64) {
+        let coordinator = self.reinit.coordinator.lock();
+        (
+            coordinator.endpoint_revision,
+            coordinator.floor_policy_revision,
+        )
+    }
+
+    /// Captures floor-affecting values under the coordinator without recursively acquiring it.
+    pub(super) fn floor_policy_values(&self) -> [u64; 14] {
+        let floor = &self.floor_runtime;
+        [
+            self.single_endpoint_runtime
+                .me_single_endpoint_shadow_writers
+                .load(Ordering::Relaxed) as u64,
+            floor.me_floor_mode.load(Ordering::Relaxed) as u64,
+            floor.me_adaptive_floor_idle_secs.load(Ordering::Relaxed),
+            floor
+                .me_adaptive_floor_min_writers_single_endpoint
+                .load(Ordering::Relaxed) as u64,
+            floor
+                .me_adaptive_floor_min_writers_multi_endpoint
+                .load(Ordering::Relaxed) as u64,
+            floor
+                .me_adaptive_floor_recover_grace_secs
+                .load(Ordering::Relaxed),
+            floor
+                .me_adaptive_floor_writers_per_core_total
+                .load(Ordering::Relaxed) as u64,
+            floor
+                .me_adaptive_floor_cpu_cores_override
+                .load(Ordering::Relaxed) as u64,
+            floor
+                .me_adaptive_floor_max_extra_writers_single_per_core
+                .load(Ordering::Relaxed) as u64,
+            floor
+                .me_adaptive_floor_max_extra_writers_multi_per_core
+                .load(Ordering::Relaxed) as u64,
+            floor
+                .me_adaptive_floor_max_active_writers_per_core
+                .load(Ordering::Relaxed) as u64,
+            floor
+                .me_adaptive_floor_max_warm_writers_per_core
+                .load(Ordering::Relaxed) as u64,
+            floor
+                .me_adaptive_floor_max_active_writers_global
+                .load(Ordering::Relaxed) as u64,
+            floor
+                .me_adaptive_floor_max_warm_writers_global
+                .load(Ordering::Relaxed) as u64,
+        ]
+    }
+}

src/transport/middle_proxy/pool/floor_authority/tests.rs

@@ -0,0 +1,96 @@
+use super::*;
+use crate::config::GeneralConfig;
+use crate::transport::middle_proxy::pool_writer_security_tests::make_pool;
+
+fn reload(pool: &MePool, cfg: &GeneralConfig) {
+    pool.update_runtime_reinit_policy(
+        cfg.hardswap,
+        cfg.me_pool_drain_ttl_secs,
+        cfg.me_instadrain,
+        cfg.me_pool_drain_threshold,
+        cfg.me_pool_drain_soft_evict_enabled,
+        cfg.me_pool_drain_soft_evict_grace_secs,
+        cfg.me_pool_drain_soft_evict_per_writer,
+        cfg.me_pool_drain_soft_evict_budget_per_core,
+        cfg.me_pool_drain_soft_evict_cooldown_ms,
+        cfg.effective_me_pool_force_close_secs(),
+        cfg.me_pool_min_fresh_ratio,
+        cfg.me_hardswap_warmup_delay_min_ms,
+        cfg.me_hardswap_warmup_delay_max_ms,
+        cfg.me_hardswap_warmup_extra_passes,
+        cfg.me_hardswap_warmup_pass_backoff_base_ms,
+        cfg.me_bind_stale_mode,
+        cfg.me_bind_stale_ttl_secs,
+        cfg.me_secret_atomic_snapshot,
+        cfg.me_deterministic_writer_sort,
+        cfg.me_writer_pick_mode,
+        cfg.me_writer_pick_sample_size,
+        cfg.me_single_endpoint_shadow_writers,
+        cfg.me_single_endpoint_outage_mode_enabled,
+        cfg.me_single_endpoint_outage_disable_quarantine,
+        cfg.me_single_endpoint_outage_backoff_min_ms,
+        cfg.me_single_endpoint_outage_backoff_max_ms,
+        cfg.me_single_endpoint_shadow_rotate_every_secs,
+        cfg.me_floor_mode,
+        cfg.me_adaptive_floor_idle_secs,
+        cfg.me_adaptive_floor_min_writers_single_endpoint,
+        cfg.me_adaptive_floor_min_writers_multi_endpoint,
+        cfg.me_adaptive_floor_recover_grace_secs,
+        cfg.me_adaptive_floor_writers_per_core_total,
+        cfg.me_adaptive_floor_cpu_cores_override,
+        cfg.me_adaptive_floor_max_extra_writers_single_per_core,
+        cfg.me_adaptive_floor_max_extra_writers_multi_per_core,
+        cfg.me_adaptive_floor_max_active_writers_per_core,
+        cfg.me_adaptive_floor_max_warm_writers_per_core,
+        cfg.me_adaptive_floor_max_active_writers_global,
+        cfg.me_adaptive_floor_max_warm_writers_global,
+        cfg.me_health_interval_ms_unhealthy,
+        cfg.me_health_interval_ms_healthy,
+        cfg.me_warn_rate_limit_ms,
+    );
+}
+
+#[tokio::test]
+async fn policy_reload_invalidates_old_caps_and_rejects_stale_plan_publication() {
+    let pool = make_pool().await;
+    let mut cfg = GeneralConfig::default();
+    reload(&pool, &cfg);
+    let authority = pool.floor_authority();
+    pool.set_adaptive_floor_runtime_caps(authority, 10, 12, 10, 12, 6, 6, 0);
+    assert_eq!(
+        pool.floor_runtime
+            .me_adaptive_floor_active_cap_effective
+            .load(Ordering::Acquire),
+        12
+    );
+    cfg.me_single_endpoint_shadow_writers += 1;
+    reload(&pool, &cfg);
+    assert_ne!(pool.floor_authority(), authority);
+    assert_eq!(
+        pool.floor_runtime
+            .me_adaptive_floor_active_cap_effective
+            .load(Ordering::Acquire),
+        0
+    );
+    pool.set_adaptive_floor_runtime_caps(authority, 10, 128, 10, 128, 100, 6, 0);
+    assert_eq!(
+        pool.floor_runtime
+            .me_adaptive_floor_active_cap_effective
+            .load(Ordering::Acquire),
+        0
+    );
+    let new_authority = pool.floor_authority();
+    reload(&pool, &cfg);
+    assert_eq!(
+        pool.floor_authority(),
+        new_authority,
+        "unchanged reload must not supersede work"
+    );
+    pool.set_adaptive_floor_runtime_caps(new_authority, 10, 11, 10, 11, 6, 6, 0);
+    assert_eq!(
+        pool.floor_runtime
+            .me_adaptive_floor_active_cap_effective
+            .load(Ordering::Acquire),
+        11
+    );
+}

src/transport/middle_proxy/pool/runtime_policy.rs

@@ -305,6 +305,8 @@ impl MePool {
         if previous_writer_pick_mode != writer_pick_mode {
             self.stats.increment_me_writer_pick_mode_switch_total();
         }
+        let mut coordinator = self.reinit.coordinator.lock();
+        let previous_floor_policy = self.floor_policy_values();
         self.single_endpoint_runtime
             .me_single_endpoint_shadow_writers
             .store(single_endpoint_shadow_writers, Ordering::Relaxed);
@@ -381,6 +383,17 @@ impl MePool {
         self.floor_runtime
             .me_adaptive_floor_max_warm_writers_global
             .store(adaptive_floor_max_warm_writers_global, Ordering::Relaxed);
+        if previous_floor_policy != self.floor_policy_values() {
+            coordinator.floor_policy_revision = coordinator.floor_policy_revision.wrapping_add(1);
+            // Cached caps belong to the old policy until a new health plan is accepted.
+            self.floor_runtime
+                .me_adaptive_floor_active_cap_effective
+                .store(0, Ordering::Release);
+            self.floor_runtime
+                .me_adaptive_floor_warm_cap_effective
+                .store(0, Ordering::Release);
+        }
+        drop(coordinator);
         self.health_runtime
             .me_health_interval_ms_unhealthy
             .store(me_health_interval_ms_unhealthy.max(1), Ordering::Relaxed);

src/transport/middle_proxy/pool/selection_policy.rs

@@ -230,8 +230,10 @@ impl MePool {
         configured
     }
 
+    /// Publishes derived caps only while both endpoint and floor-policy authority remain current.
     pub(in crate::transport::middle_proxy) fn set_adaptive_floor_runtime_caps(
         &self,
+        authority: (u64, u64),
         active_cap_configured: usize,
         active_cap_effective: usize,
         warm_cap_configured: usize,
@@ -240,6 +242,15 @@ impl MePool {
         active_writers_current: usize,
         warm_writers_current: usize,
     ) {
+        let coordinator = self.reinit.coordinator.lock();
+        if authority
+            != (
+                coordinator.endpoint_revision,
+                coordinator.floor_policy_revision,
+            )
+        {
+            return;
+        }
         self.floor_runtime
             .me_adaptive_floor_global_cap_raw
             .store(active_cap_configured as u64, Ordering::Relaxed);

src/transport/middle_proxy/pool/writer_admission.rs

@@ -48,13 +48,13 @@ pub(in crate::transport::middle_proxy) enum WriterOpenIntent {
 }
 
 /// RAII ownership of one bounded in-flight writer open.
-pub(in crate::transport::middle_proxy) struct WriterOpenReservation<'a> {
-    counter: Option<&'a AtomicUsize>,
+pub(in crate::transport::middle_proxy) struct WriterOpenReservation {
+    counter: Option<Arc<AtomicUsize>>,
 }
 
-impl Drop for WriterOpenReservation<'_> {
+impl Drop for WriterOpenReservation {
     fn drop(&mut self) {
-        if let Some(counter) = self.counter {
+        if let Some(counter) = &self.counter {
             counter.fetch_sub(1, Ordering::AcqRel);
         }
     }
@@ -172,7 +172,7 @@ impl MePool {
         intent: WriterOpenIntent,
         writer_dc: i32,
         target_addr: SocketAddr,
-    ) -> Option<WriterOpenReservation<'_>> {
+    ) -> Option<WriterOpenReservation> {
         let counter = match contour {
             WriterContour::Active => &self.writer_connect_active_reserved,
             WriterContour::Warm => &self.writer_connect_warm_reserved,
@@ -182,6 +182,8 @@ impl MePool {
         };
 
         if intent == WriterOpenIntent::Replacement {
+            // Policy reload and replacement admission share the same linearization point.
+            let _coordinator = self.reinit.coordinator.lock();
             let configured_cap = match contour {
                 WriterContour::Active => self.adaptive_floor_active_cap_configured_total(),
                 WriterContour::Warm => self.adaptive_floor_warm_cap_configured_total(),
@@ -220,7 +222,7 @@ impl MePool {
                     .is_ok()
                 {
                     return Some(WriterOpenReservation {
-                        counter: Some(&self.writer_replacement_open_reserved),
+                        counter: Some(self.writer_replacement_open_reserved.clone()),
                     });
                 }
             }
@@ -266,7 +268,7 @@ impl MePool {
                 .is_ok()
             {
                 return Some(WriterOpenReservation {
-                    counter: Some(counter),
+                    counter: Some(counter.clone()),
                 });
             }
         }

src/transport/middle_proxy/pool_lifecycle.rs

@@ -111,6 +111,31 @@ impl MePoolLifecycle {
         self.admission.try_register()
     }
 
+    /// Registers a cancellation-aware producer for a caller-owned JoinSet without a second spawn.
+    pub(super) fn track_producer<F>(
+        &self,
+        future: F,
+    ) -> Result<impl Future<Output = Option<F::Output>> + Send + 'static + use<F>, F>
+    where
+        F: Future + Send + 'static,
+        F::Output: Send + 'static,
+    {
+        let Some(registration) = self.try_register() else {
+            return Err(future);
+        };
+        let cancel = self.producer_cancel.clone();
+        let tracked = self.producer_tasks.track_future(async move {
+            tokio::select! {
+                biased;
+                _ = cancel.cancelled() => None,
+                output = future => Some(output),
+            }
+        });
+        // The tracker owns destruction before shutdown can observe no registrations.
+        drop(registration);
+        Ok(tracked)
+    }
+
     /// Registers and spawns one cancellation-aware ME producer.
     pub(super) fn spawn_producer<F>(&self, future: F) -> Result<(), F>
     where

src/transport/middle_proxy/pool_nat.rs

@@ -26,6 +26,9 @@ const HTTP_FAILURE_TTL: Duration = Duration::from_secs(60);
 // Discovery ownership and source-bound cache admission for this pool generation.
 mod state;
 pub(super) use state::NatDiscovery;
+// Successful HTTP observations expire independently of failure backoff.
+mod http;
+pub(super) use http::HttpNatObservation;
 
 // Local network regressions exercise cancellation before discovery publication.
 #[cfg(test)]
@@ -167,14 +170,16 @@ impl MePool {
 
     /// Applies the configured or HTTP-detected NAT IP to non-public addresses.
     pub(super) fn translate_ip_for_nat(&self, ip: IpAddr) -> IpAddr {
-        let nat_ip = self.nat_runtime.nat_ip_cfg.or_else(|| {
+        Self::translate_ip_with_nat(
+            ip,
             self.nat_runtime
-                .nat_ip_detected
-                .try_read()
-                .ok()
-                .and_then(|g| *g)
-        });
+                .nat_ip_cfg
+                .or_else(|| self.cached_http_nat_ip()),
+        )
+    }
 
+    /// Applies a captured NAT observation without rereading mutable discovery state.
+    pub(super) fn translate_ip_with_nat(ip: IpAddr, nat_ip: Option<IpAddr>) -> IpAddr {
         let Some(nat_ip) = nat_ip else {
             return ip;
         };
@@ -197,6 +202,16 @@ impl MePool {
         &self,
         addr: std::net::SocketAddr,
         reflected: Option<std::net::SocketAddr>,
+    ) -> std::net::SocketAddr {
+        self.translate_our_addr_with_nat(addr, reflected, self.cached_http_nat_ip())
+    }
+
+    /// Retains the actual TCP port while using one handshake-local NAT snapshot.
+    pub(super) fn translate_our_addr_with_nat(
+        &self,
+        addr: std::net::SocketAddr,
+        reflected: Option<std::net::SocketAddr>,
+        detected: Option<IpAddr>,
     ) -> std::net::SocketAddr {
         let ip = if let Some(nat_ip) = self.nat_runtime.nat_ip_cfg {
             match (addr.ip(), nat_ip) {
@@ -209,63 +224,16 @@ impl MePool {
             if is_bogon(addr.ip()) || addr.ip().is_loopback() || addr.ip().is_unspecified() {
                 r.ip()
             } else {
-                self.translate_ip_for_nat(addr.ip())
+                Self::translate_ip_with_nat(addr.ip(), detected)
             }
         } else {
-            self.translate_ip_for_nat(addr.ip())
+            Self::translate_ip_with_nat(addr.ip(), detected)
         };
 
         // Keep the kernel-assigned TCP source port; STUN port can differ.
         std::net::SocketAddr::new(ip, addr.port())
     }
 
-    /// Waits for pool-owned HTTP discovery without owning its cancellation.
-    pub(super) async fn maybe_detect_nat_ip(self: &Arc<Self>, local_ip: IpAddr) -> Option<IpAddr> {
-        if self.nat_runtime.nat_ip_cfg.is_some() {
-            return self.nat_runtime.nat_ip_cfg;
-        }
-
-        if !self.nat_runtime.nat_probe {
-            return None;
-        }
-
-        if !(is_bogon(local_ip) || local_ip.is_loopback() || local_ip.is_unspecified()) {
-            return None;
-        }
-
-        if let Some(ip) = *self.nat_runtime.nat_ip_detected.read().await {
-            return Some(ip);
-        }
-
-        let mut flight = self.nat_runtime.discovery.http.clone().lock_owned().await;
-        if let Some(ip) = *self.nat_runtime.nat_ip_detected.read().await {
-            return Some(ip);
-        }
-        if flight.is_some_and(|until| Instant::now() < until) {
-            return None;
-        }
-
-        let pool = self.clone();
-        let (send, receive) = oneshot::channel();
-        // Transfer singleflight ownership before the producer can be cancelled or polled.
-        self.lifecycle
-            .spawn_producer(async move {
-                let detected = detect_public_ipv4_http(&pool.nat_runtime.http_ip_detect_urls)
-                    .await
-                    .map(IpAddr::V4);
-                if let Some(ip) = detected {
-                    *pool.nat_runtime.nat_ip_detected.write().await = Some(ip);
-                    *flight = None;
-                    info!(public_ip = %ip, "Auto-detected public IP for NAT translation");
-                } else {
-                    *flight = Some(Instant::now() + HTTP_FAILURE_TTL);
-                }
-                let _ = send.send(detected);
-            })
-            .ok()?;
-        receive.await.ok().flatten()
-    }
-
     /// Waits for a pool-owned STUN refresh in the exact source-address context.
     pub(super) async fn maybe_reflect_public_addr(
         self: &Arc<Self>,

src/transport/middle_proxy/pool_nat/http.rs

@@ -0,0 +1,108 @@
+use super::*;
+
+const HTTP_FRESH_TTL: Duration = Duration::from_secs(600);
+const HTTP_MAX_AGE: Duration = Duration::from_secs(1200);
+
+/// A successful HTTP observation has an immutable monotonic timestamp.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(in crate::transport::middle_proxy) struct HttpNatObservation {
+    /// Successful detector result, never updated by a failed refresh.
+    pub(in crate::transport::middle_proxy) ip: IpAddr,
+    /// Original observation time used for both freshness and bounded stale fallback.
+    pub(super) observed_at: tokio::time::Instant,
+}
+
+impl HttpNatObservation {
+    fn usable(self) -> Option<IpAddr> {
+        (self.observed_at.elapsed() < HTTP_MAX_AGE).then_some(self.ip)
+    }
+
+    fn fresh(self) -> bool {
+        self.observed_at.elapsed() < HTTP_FRESH_TTL
+    }
+}
+
+impl MePool {
+    /// Reads a bounded cache snapshot without discovery or data-plane waiting.
+    pub(in crate::transport::middle_proxy) fn cached_http_nat_ip(&self) -> Option<IpAddr> {
+        self.nat_runtime
+            .nat_ip_detected
+            .try_read()
+            .ok()
+            .and_then(|cache| cache.and_then(HttpNatObservation::usable))
+    }
+
+    /// Refreshes once per pool, retaining stale success only within its original grace period.
+    pub(in crate::transport::middle_proxy) async fn maybe_detect_nat_ip(
+        self: &Arc<Self>,
+        local_ip: IpAddr,
+    ) -> Option<IpAddr> {
+        if self.nat_runtime.nat_ip_cfg.is_some() {
+            return self.nat_runtime.nat_ip_cfg;
+        }
+        if !self.nat_runtime.nat_probe
+            || !local_ip.is_ipv4()
+            || !(is_bogon(local_ip) || local_ip.is_loopback() || local_ip.is_unspecified())
+        {
+            return None;
+        }
+        if let Some(cached) = *self.nat_runtime.nat_ip_detected.read().await
+            && cached.fresh()
+        {
+            return Some(cached.ip);
+        }
+        let mut flight = self.nat_runtime.discovery.http.clone().lock_owned().await;
+        let cached = *self.nat_runtime.nat_ip_detected.read().await;
+        if let Some(cached) = cached
+            && cached.fresh()
+        {
+            return Some(cached.ip);
+        }
+        if flight.is_some_and(|until| Instant::now() < until) {
+            return cached.and_then(HttpNatObservation::usable);
+        }
+        let pool = self.clone();
+        let (send, receive) = oneshot::channel();
+        // Discovery owns the flight; cancellation of a handshake cannot cancel publication.
+        self.lifecycle
+            .spawn_producer(async move {
+                let detected = detect_public_ipv4_http(&pool.nat_runtime.http_ip_detect_urls)
+                    .await
+                    .map(IpAddr::V4);
+                if let Some(ip) = detected {
+                    *pool.nat_runtime.nat_ip_detected.write().await = Some(HttpNatObservation {
+                        ip,
+                        observed_at: tokio::time::Instant::now(),
+                    });
+                    *flight = None;
+                    info!(public_ip = %ip, "Auto-detected public IP for NAT translation");
+                } else {
+                    *flight = Some(Instant::now() + HTTP_FAILURE_TTL);
+                }
+                let _ = send.send(());
+            })
+            .ok()?;
+        let _ = receive.await;
+        self.cached_http_nat_ip()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test(start_paused = true)]
+    async fn observation_age_is_not_renewed_by_reads_or_failure() {
+        let cached = HttpNatObservation {
+            ip: "91.108.56.1".parse().unwrap(),
+            observed_at: tokio::time::Instant::now(),
+        };
+        tokio::time::advance(HTTP_FRESH_TTL).await;
+        assert!(!cached.fresh());
+        for _ in 0..100 {
+            assert_eq!(cached.usable(), Some(cached.ip));
+        }
+        tokio::time::advance(HTTP_MAX_AGE - HTTP_FRESH_TTL).await;
+        assert_eq!(cached.usable(), None);
+    }
+}

src/transport/middle_proxy/pool_nat/tests.rs

@@ -18,6 +18,7 @@ pub(super) const PUBLIC_IP: Ipv4Addr = Ipv4Addr::new(91, 108, 56, 1);
 pub(super) const TEST_DEADLINE: Duration = Duration::from_secs(2);
 
 // Concurrency and end-to-end regressions share gated local discovery servers.
+mod freshness;
 pub(super) mod lifecycle;
 mod recovery;
 
@@ -243,7 +244,11 @@ async fn http_discovery_survives_reconnect_timeout() {
     .await
     .expect("pool-owned HTTP discovery must publish after caller cancellation");
     assert_eq!(
-        *pool.nat_runtime.nat_ip_detected.read().await,
+        pool.nat_runtime
+            .nat_ip_detected
+            .read()
+            .await
+            .map(|observation| observation.ip),
         Some(PUBLIC_IP.into())
     );
     assert_eq!(http.requests.load(Ordering::Relaxed), 1);

src/transport/middle_proxy/pool_nat/tests/freshness.rs

@@ -0,0 +1,75 @@
+use super::*;
+
+#[tokio::test]
+async fn failed_refresh_retains_original_age_but_never_expired_material() {
+    let http = http_server("invalid address").await;
+    http.release.add_permits(8);
+    let pool = nat_pool(vec![], vec![format!("http://{}/", http.addr)]).await;
+    let observed_at = tokio::time::Instant::now() - Duration::from_secs(601);
+    *pool.nat_runtime.nat_ip_detected.write().await = Some(HttpNatObservation {
+        ip: PUBLIC_IP.into(),
+        observed_at,
+    });
+    assert_eq!(
+        pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()).await,
+        Some(PUBLIC_IP.into())
+    );
+    assert_eq!(
+        pool.nat_runtime
+            .nat_ip_detected
+            .read()
+            .await
+            .unwrap()
+            .observed_at,
+        observed_at
+    );
+    assert_eq!(http.requests.load(Ordering::Acquire), 1);
+    assert_eq!(
+        pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()).await,
+        Some(PUBLIC_IP.into())
+    );
+    assert_eq!(
+        http.requests.load(Ordering::Acquire),
+        1,
+        "failure backoff remains singleflight"
+    );
+    pool.nat_runtime
+        .nat_ip_detected
+        .write()
+        .await
+        .as_mut()
+        .unwrap()
+        .observed_at = tokio::time::Instant::now() - Duration::from_secs(1201);
+    assert_eq!(
+        pool.maybe_detect_nat_ip(Ipv4Addr::LOCALHOST.into()).await,
+        None
+    );
+    assert_eq!(
+        pool.translate_ip_for_nat(Ipv4Addr::LOCALHOST.into()),
+        IpAddr::V4(Ipv4Addr::LOCALHOST)
+    );
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}
+
+#[tokio::test]
+async fn expired_http_observation_defers_handshake_before_sending_kdf_material() {
+    let pool = nat_pool(vec![], vec![]).await;
+    *pool.nat_runtime.nat_ip_detected.write().await = Some(HttpNatObservation {
+        ip: PUBLIC_IP.into(),
+        observed_at: tokio::time::Instant::now() - Duration::from_secs(1201),
+    });
+    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let addr = listener.local_addr().unwrap();
+    let stream = tokio::net::TcpStream::connect(addr).await.unwrap();
+    let (mut peer, _) = listener.accept().await.unwrap();
+    let error = pool
+        .handshake_only(stream, addr, None, pool.rng.as_ref())
+        .await
+        .err()
+        .unwrap();
+    assert!(
+        matches!(error, ProxyError::Io(ref error) if error.kind() == std::io::ErrorKind::WouldBlock)
+    );
+    assert_eq!(peer.read(&mut [0u8; 1]).await.unwrap(), 0);
+    assert!(pool.shutdown_until(TEST_DEADLINE).await);
+}

src/transport/middle_proxy/pool_nat/tests/recovery.rs

@@ -24,7 +24,11 @@ impl Drop for MiddlePeer {
 
 impl MiddlePeer {
     async fn new(server_ip: Ipv4Addr) -> Self {
-        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        Self::with_bind("127.0.0.1:0", server_ip.into(), PUBLIC_IP.into()).await
+    }
+
+    async fn with_bind(bind: &str, server_ip: IpAddr, client_ip: IpAddr) -> Self {
+        let listener = TcpListener::bind(bind).await.unwrap();
         let addr = listener.local_addr().unwrap();
         let handshakes = Arc::new(AtomicUsize::new(0));
         let cancelled = Arc::new(AtomicUsize::new(0));
@@ -37,7 +41,7 @@ impl MiddlePeer {
                 tokio::select! {
                     accepted = listener.accept() => {
                         let (stream, _) = accepted.unwrap();
-                        pending.spawn(accept_handshake(stream, server_ip));
+                        pending.spawn(accept_handshake(stream, server_ip, client_ip));
                     }
                     completed = pending.join_next(), if !pending.is_empty() => {
                         match completed.unwrap().expect("fake ME handshake task must not panic") {
@@ -60,7 +64,11 @@ impl MiddlePeer {
     }
 }
 
-async fn accept_handshake(mut stream: TcpStream, server_ip: Ipv4Addr) -> Option<TcpStream> {
+async fn accept_handshake(
+    mut stream: TcpStream,
+    server_ip: IpAddr,
+    client_ip: IpAddr,
+) -> Option<TcpStream> {
     let client_port = stream.peer_addr().unwrap().port();
     let server_port = stream.local_addr().unwrap().port();
     let (seq, payload) = match read_rpc_frame_plaintext(&mut stream).await {
@@ -79,35 +87,43 @@ async fn accept_handshake(mut stream: TcpStream, server_ip: Ipv4Addr) -> Option<
         .write_all(&build_rpc_frame(-2, &nonce, RpcChecksumMode::Crc32))
         .await
         .unwrap();
-    let mut client_ip = PUBLIC_IP.octets();
-    client_ip.reverse();
-    let mut server_ip = server_ip.octets();
-    server_ip.reverse();
+    let split = |ip: IpAddr| match ip {
+        IpAddr::V4(ip) => {
+            let mut octets = ip.octets();
+            octets.reverse();
+            (Some(octets), None)
+        }
+        IpAddr::V6(ip) => (None, Some(ip.octets())),
+    };
+    let (client_v4, client_v6) = split(client_ip);
+    let (server_v4, server_v6) = split(server_ip);
+    let client_ip = client_v4.unwrap_or([0; 4]);
+    let server_ip = server_v4.unwrap_or([0; 4]);
     let (read_key, read_iv) = derive_middleproxy_keys(
         &server_nonce,
         &client_nonce,
         &timestamp.to_le_bytes(),
-        Some(&server_ip),
+        server_v4.as_ref().map(|ip| ip.as_slice()),
         &client_port.to_le_bytes(),
         b"CLIENT",
-        Some(&client_ip),
+        client_v4.as_ref().map(|ip| ip.as_slice()),
         &server_port.to_le_bytes(),
         &[1u8; 32],
-        None,
-        None,
+        client_v6.as_ref(),
+        server_v6.as_ref(),
     );
     let (write_key, write_iv) = derive_middleproxy_keys(
         &server_nonce,
         &client_nonce,
         &timestamp.to_le_bytes(),
-        Some(&server_ip),
+        server_v4.as_ref().map(|ip| ip.as_slice()),
         &client_port.to_le_bytes(),
         b"SERVER",
-        Some(&client_ip),
+        client_v4.as_ref().map(|ip| ip.as_slice()),
         &server_port.to_le_bytes(),
         &[1u8; 32],
-        None,
-        None,
+        client_v6.as_ref(),
+        server_v6.as_ref(),
     );
     let mut encrypted = [0u8; 48];
     stream.read_exact(&mut encrypted).await.unwrap();
@@ -151,12 +167,8 @@ async fn suppressed_pool_recovers_after_delayed_discovery(http_slow: bool) {
     let http = http_server_with_delay("91.108.56.1", delay).await;
     stun.release.add_permits(64);
     http.release.add_permits(64);
-    let peer = MiddlePeer::new(if http_slow {
-        PUBLIC_IP
-    } else {
-        Ipv4Addr::LOCALHOST
-    })
-    .await;
+    // A valid STUN source bypasses HTTP; the peer remains the configured loopback endpoint.
+    let peer = MiddlePeer::new(Ipv4Addr::LOCALHOST).await;
     let urls = if http_slow {
         vec![format!("http://{}/", http.addr)]
     } else {
@@ -178,6 +190,9 @@ async fn suppressed_pool_recovers_after_delayed_discovery(http_slow: bool) {
     pool.single_endpoint_runtime
         .me_single_endpoint_shadow_writers
         .store(0, Ordering::Relaxed);
+    pool.single_endpoint_runtime
+        .me_single_endpoint_shadow_rotate_every_secs
+        .store(0, Ordering::Relaxed);
     pool.update_proxy_maps(
         HashMap::from([(2, vec![(peer.addr.ip(), peer.addr.port())])]),
         None,
@@ -206,20 +221,18 @@ async fn suppressed_pool_recovers_after_delayed_discovery(http_slow: bool) {
         Arc::new(SecureRandom::new()),
         0,
     ));
-    if http_slow {
-        http.received().await;
-    } else {
+    if !http_slow {
         stun.received().await;
+        timeout(Duration::from_secs(5), async {
+            while peer.cancelled.load(Ordering::Acquire) == 0 {
+                assert!(!peer.task.is_finished());
+                tokio::time::sleep(Duration::from_millis(10)).await;
+            }
+        })
+        .await
+        .expect("the actual 1200ms reconnect must cancel a pre-KDF TCP connection");
+        assert_eq!(peer.handshakes.load(Ordering::Acquire), 0);
     }
-    timeout(Duration::from_secs(5), async {
-        while peer.cancelled.load(Ordering::Acquire) == 0 {
-            assert!(!peer.task.is_finished());
-            tokio::time::sleep(Duration::from_millis(10)).await;
-        }
-    })
-    .await
-    .expect("the actual 1200ms reconnect must cancel at least one pre-KDF TCP connection");
-    assert_eq!(peer.handshakes.load(Ordering::Acquire), 0);
     let expected = 2 * pool.required_writers_for_dc(1);
     timeout(Duration::from_secs(10), async {
         while !pool.admission_ready_full_floor().await
@@ -244,10 +257,7 @@ async fn suppressed_pool_recovers_after_delayed_discovery(http_slow: bool) {
     );
     assert_eq!(pool.writers.read().await.len(), expected);
     assert!(peer.handshakes.load(Ordering::Acquire) >= expected);
-    assert_eq!(
-        http.requests.load(Ordering::Relaxed),
-        usize::from(http_slow)
-    );
+    assert_eq!(http.requests.load(Ordering::Relaxed), 0);
     assert_eq!(
         stun.requests.load(Ordering::Relaxed),
         usize::from(!http_slow)
@@ -264,3 +274,58 @@ async fn suppressed_pool_recovers_full_floor_after_expired_stun_refresh() {
 async fn suppressed_pool_recovers_full_floor_after_slow_http_with_fresh_stun() {
     suppressed_pool_recovers_after_delayed_discovery(true).await;
 }
+
+#[tokio::test]
+async fn stalled_ipv4_does_not_delay_real_ipv6_handshakes() {
+    let stalled = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let stalled_addr = stalled.local_addr().unwrap();
+    let healthy =
+        MiddlePeer::with_bind("[::1]:0", "::1".parse().unwrap(), "::1".parse().unwrap()).await;
+    let mut pool = make_pool_with_decision(NetworkDecision {
+        ipv4_me: true,
+        ipv6_me: true,
+        ..NetworkDecision::default()
+    })
+    .await;
+    Arc::get_mut(&mut Arc::get_mut(&mut pool).unwrap().reconnect_runtime)
+        .unwrap()
+        .me_one_timeout = Duration::from_secs(5);
+    pool.health_runtime
+        .me_health_interval_ms_unhealthy
+        .store(10, Ordering::Relaxed);
+    pool.single_endpoint_runtime
+        .me_single_endpoint_shadow_rotate_every_secs
+        .store(0, Ordering::Relaxed);
+    pool.update_proxy_maps(
+        HashMap::from([(2, vec![(stalled_addr.ip(), stalled_addr.port())])]),
+        Some(HashMap::from([(
+            2,
+            vec![(healthy.addr.ip(), healthy.addr.port())],
+        )])),
+    )
+    .await;
+    let monitor = tokio::spawn(me_health_monitor(pool.clone(), pool.rng.clone(), 0));
+    let (blocked_stream, _) = timeout(TEST_DEADLINE, stalled.accept())
+        .await
+        .unwrap()
+        .unwrap();
+    timeout(TEST_DEADLINE, async {
+        while healthy.handshakes.load(Ordering::Acquire) < pool.required_writers_for_dc(1) {
+            assert!(!healthy.task.is_finished());
+            tokio::time::sleep(Duration::from_millis(10)).await;
+        }
+    })
+    .await
+    .expect("IPv6 must restore coverage while IPv4 still owns a stalled handshake");
+    monitor.abort();
+    let _ = monitor.await;
+    assert!(
+        pool.shutdown_until(TEST_DEADLINE).await,
+        "tracked child transports must join on shutdown"
+    );
+    drop(blocked_stream);
+    assert_eq!(
+        pool.writer_connect_active_reserved.load(Ordering::Acquire),
+        0
+    );
+}

src/transport/middle_proxy/pool_reinit/coordination.rs

@@ -491,7 +491,11 @@ impl MePool {
         rand::rng().random_range(min_ms..=max_ms)
     }
 
-    pub(super) fn hardswap_warmup_backoff_ms(&self, pass_idx: usize) -> u64 {
+    /// Returns capped exponential retry delay with bounded positive jitter.
+    pub(in crate::transport::middle_proxy) fn hardswap_warmup_backoff_ms(
+        &self,
+        pass_idx: usize,
+    ) -> u64 {
         let base_ms = self
             .reinit
             .me_hardswap_warmup_pass_backoff_base_ms

src/transport/middle_proxy/pool_reinit/reconcile.rs

@@ -169,11 +169,21 @@ impl MePool {
         }
     }
 
+    /// Reconciles one immutable endpoint snapshot without draining uncovered groups.
     pub async fn zero_downtime_reinit_after_map_change(
         self: &Arc<Self>,
         rng: &SecureRandom,
     ) -> bool {
         let endpoint_snapshot = self.endpoint_snapshot.load_full();
+        self.reinit_endpoint_snapshot(rng, endpoint_snapshot).await
+    }
+
+    /// Reconciles exactly the revision owned by the scheduler's retry objective.
+    pub(in crate::transport::middle_proxy) async fn reinit_endpoint_snapshot(
+        self: &Arc<Self>,
+        rng: &SecureRandom,
+        endpoint_snapshot: Arc<EndpointSnapshot>,
+    ) -> bool {
         let desired_by_dc = self.desired_dc_endpoints_from_snapshot(&endpoint_snapshot);
         let now_epoch_secs = Self::now_epoch_secs();
         let v4_suppressed = self.is_family_temporarily_suppressed(IpFamily::V4, now_epoch_secs);
@@ -407,6 +417,7 @@ impl MePool {
         true
     }
 
+    /// Applies periodic rotation using the same coverage and generation fences as map changes.
     pub async fn zero_downtime_reinit_periodic(self: &Arc<Self>, rng: &SecureRandom) -> bool {
         self.zero_downtime_reinit_after_map_change(rng).await
     }

src/transport/middle_proxy/pool_reinit/tests.rs

@@ -149,6 +149,7 @@ fn stale_concurrent_attempt_cannot_regress_active_generation() {
         active_generation: 1,
         desired_map_hash: 22,
         endpoint_revision: 7,
+        floor_policy_revision: 1,
         pending: Some(ReinitPendingState {
             generation: 3,
             started_at_epoch_secs: 1,

src/transport/middle_proxy/pool_writer.rs

@@ -32,6 +32,9 @@ use super::wire::build_proxy_req_payload;
 mod publication;
 mod replacement;
 mod runtime;
+// Physical replacement overlap survives logical writer removal until transport destruction.
+pub(super) mod overlap;
+use overlap::WriterTransport;
 
 // Recovery regressions exercise the serialized production publication boundary.
 #[cfg(test)]
@@ -42,9 +45,8 @@ struct PreparedWriter<'a> {
     tx: mpsc::Sender<WriterCommand>,
     byte_budget: Arc<tokio::sync::Semaphore>,
     task_registration: MeTaskRegistration<'a>,
-    writer_task: Pin<Box<dyn Future<Output = ()> + Send + 'static>>,
+    writer_task: WriterTransport,
     intent: WriterOpenIntent,
-    _open_reservation: WriterOpenReservation<'a>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -59,6 +61,13 @@ pub(super) enum WriterReplacementPurpose {
         /// Target count above which the receiver no longer needs the slot.
         receiver_floor: usize,
     },
+    /// Transfers one slot without taking a current donor below its protected base floor.
+    CoverageTransfer {
+        /// Endpoint and floor-policy authority captured before selecting the donor.
+        authority: (u64, u64),
+        /// Planned receiver target, revalidated against current policy at commit.
+        receiver_floor: usize,
+    },
     /// Replaces a stale-generation writer with an active-generation writer.
     GenerationConvergence,
     /// Rotates a single-endpoint shadow while retaining coverage.
@@ -72,6 +81,7 @@ impl WriterReplacementPurpose {
         match self {
             Self::IdleRefresh => "idle_refresh",
             Self::FloorRebalance { .. } => "floor_rebalance",
+            Self::CoverageTransfer { .. } => "coverage_transfer",
             Self::GenerationConvergence => "generation_convergence",
             Self::ShadowRotation => "shadow_rotation",
             Self::SecretRotation => "secret_rotation",

src/transport/middle_proxy/pool_writer/overlap.rs

@@ -0,0 +1,87 @@
+use super::*;
+use std::task::{Context, Poll};
+
+/// Writer-local physical lifetime, independent of registry visibility.
+pub(in crate::transport::middle_proxy) struct ReplacementHandoff {
+    state: parking_lot::Mutex<HandoffState>,
+}
+
+enum HandoffState {
+    Open(Option<WriterOpenReservation>),
+    Closed,
+}
+
+impl ReplacementHandoff {
+    /// Creates a handoff that may accept one physical-overlap token.
+    pub(in crate::transport::middle_proxy) fn new() -> Arc<Self> {
+        Arc::new(Self {
+            state: parking_lot::Mutex::new(HandoffState::Open(None)),
+        })
+    }
+
+    fn close(&self) {
+        *self.state.lock() = HandoffState::Closed;
+    }
+
+    /// Keeps attachment reversible until the final registry validation has succeeded.
+    pub(super) fn commit(
+        &self,
+        permit: &mut Option<WriterOpenReservation>,
+        validate: impl FnOnce() -> bool,
+    ) -> bool {
+        let mut state = self.state.lock();
+        match &mut *state {
+            HandoffState::Open(slot) if slot.is_none() && permit.is_some() && validate() => {
+                *slot = permit.take();
+                true
+            }
+            _ => false,
+        }
+    }
+}
+
+/// Destroys transport futures before releasing either opening or retiring capacity.
+pub(super) struct WriterTransport {
+    future: Option<Pin<Box<dyn Future<Output = ()> + Send + 'static>>>,
+    /// Shared with the registry but closed only by transport destruction.
+    pub(super) lifetime: Arc<ReplacementHandoff>,
+    /// Moves to the victim on replacement or is released after normal publication.
+    pub(super) opening: Option<WriterOpenReservation>,
+}
+
+impl WriterTransport {
+    /// Owns prepared transports even if their task is never polled or published.
+    pub(super) fn new(
+        future: Pin<Box<dyn Future<Output = ()> + Send + 'static>>,
+        opening: WriterOpenReservation,
+    ) -> Self {
+        Self {
+            future: Some(future),
+            lifetime: ReplacementHandoff::new(),
+            opening: Some(opening),
+        }
+    }
+}
+
+impl Future for WriterTransport {
+    type Output = ();
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<()> {
+        match self.future.as_mut() {
+            Some(future) => future.as_mut().poll(cx),
+            None => Poll::Ready(()),
+        }
+    }
+}
+
+impl Drop for WriterTransport {
+    fn drop(&mut self) {
+        // Explicit order also applies to unpolled futures, panic unwinding and abort.
+        drop(self.future.take());
+        self.lifetime.close();
+        drop(self.opening.take());
+    }
+}
+
+#[cfg(test)]
+mod tests;

src/transport/middle_proxy/pool_writer/overlap/tests.rs

@@ -0,0 +1,238 @@
+use super::*;
+use crate::transport::middle_proxy::pool_writer_security_tests::make_pool;
+use std::sync::atomic::AtomicUsize;
+
+struct DestructionProbe {
+    counter: Arc<AtomicUsize>,
+    destroyed: Arc<AtomicBool>,
+}
+
+impl Drop for DestructionProbe {
+    fn drop(&mut self) {
+        assert!(
+            self.counter.load(Ordering::Acquire) > 0,
+            "transport must be destroyed before its overlap token"
+        );
+        self.destroyed.store(true, Ordering::Release);
+    }
+}
+
+async fn transport(pool: &Arc<MePool>, destroyed: Arc<AtomicBool>) -> WriterTransport {
+    let permit = pool
+        .reserve_writer_open(
+            WriterContour::Active,
+            WriterOpenIntent::Replacement,
+            2,
+            "127.0.0.1:443".parse().unwrap(),
+        )
+        .await
+        .unwrap();
+    let probe = DestructionProbe {
+        counter: pool.writer_replacement_open_reserved.clone(),
+        destroyed,
+    };
+    WriterTransport::new(
+        Box::pin(async move {
+            let _probe = probe;
+            std::future::pending::<()>().await;
+        }),
+        permit,
+    )
+}
+
+#[tokio::test]
+async fn unpolled_transport_and_aborted_task_release_after_destruction() {
+    let pool = make_pool().await;
+    for abort in [false, true] {
+        let destroyed = Arc::new(AtomicBool::new(false));
+        let task = transport(&pool, destroyed.clone()).await;
+        if abort {
+            let task = tokio::spawn(task);
+            task.abort();
+            let _ = task.await;
+        } else {
+            drop(task);
+        }
+        assert!(destroyed.load(Ordering::Acquire));
+        assert_eq!(
+            pool.writer_replacement_open_reserved
+                .load(Ordering::Acquire),
+            0
+        );
+    }
+}
+
+#[tokio::test]
+async fn retiring_transport_owns_capacity_after_logical_removal() {
+    let pool = make_pool().await;
+    let destroyed = Arc::new(AtomicBool::new(false));
+    let mut victim = transport(&pool, destroyed.clone()).await;
+    drop(victim.opening.take());
+    let lifetime = victim.lifetime.clone();
+    let mut successor = transport(&pool, Arc::new(AtomicBool::new(false))).await;
+    successor.future = Some(Box::pin(std::future::pending()));
+    assert!(lifetime.commit(&mut successor.opening, || true));
+    assert!(successor.opening.is_none());
+    // Registry removal only drops its handle; the real transport retains the token.
+    drop(lifetime);
+    assert_eq!(
+        pool.writer_replacement_open_reserved
+            .load(Ordering::Acquire),
+        1
+    );
+    drop(victim);
+    assert!(destroyed.load(Ordering::Acquire));
+    assert_eq!(
+        pool.writer_replacement_open_reserved
+            .load(Ordering::Acquire),
+        0
+    );
+    // Successor is no longer overlap after its victim has physically gone.
+    drop(successor);
+}
+
+#[tokio::test]
+async fn failed_or_closed_handoff_keeps_the_prepared_token() {
+    let pool = make_pool().await;
+    let mut prepared = transport(&pool, Arc::new(AtomicBool::new(false))).await;
+    let lifetime = ReplacementHandoff::new();
+    assert!(!lifetime.commit(&mut prepared.opening, || false));
+    assert!(prepared.opening.is_some());
+    lifetime.close();
+    assert!(!lifetime.commit(&mut prepared.opening, || true));
+    assert!(prepared.opening.is_some());
+    drop(prepared);
+    assert_eq!(
+        pool.writer_replacement_open_reserved
+            .load(Ordering::Acquire),
+        0
+    );
+}
+
+#[tokio::test]
+async fn overlap_limit_survives_commit_and_cap_shrink_until_teardown() {
+    let pool = make_pool().await;
+    pool.floor_runtime
+        .me_adaptive_floor_cpu_cores_override
+        .store(1, Ordering::Relaxed);
+    pool.floor_runtime
+        .me_adaptive_floor_max_active_writers_per_core
+        .store(1, Ordering::Relaxed);
+    pool.floor_runtime
+        .me_adaptive_floor_max_active_writers_global
+        .store(1, Ordering::Relaxed);
+    pool.set_adaptive_floor_runtime_caps(pool.floor_authority(), 1, 2, 1, 1, 1, 0, 0);
+    let mut victim = transport(&pool, Arc::new(AtomicBool::new(false))).await;
+    drop(victim.opening.take());
+    let mut successor = transport(&pool, Arc::new(AtomicBool::new(false))).await;
+    successor.future = Some(Box::pin(std::future::pending()));
+    assert!(victim.lifetime.commit(&mut successor.opening, || true));
+    let second = transport(&pool, Arc::new(AtomicBool::new(false))).await;
+    pool.set_adaptive_floor_runtime_caps(pool.floor_authority(), 1, 1, 1, 1, 1, 1, 0);
+    let addr = "127.0.0.1:443".parse().unwrap();
+    assert!(
+        pool.reserve_writer_open(
+            WriterContour::Active,
+            WriterOpenIntent::Replacement,
+            2,
+            addr
+        )
+        .await
+        .is_none()
+    );
+    drop(second);
+    assert!(
+        pool.reserve_writer_open(
+            WriterContour::Active,
+            WriterOpenIntent::Replacement,
+            2,
+            addr
+        )
+        .await
+        .is_none()
+    );
+    drop(victim);
+    assert!(
+        pool.reserve_writer_open(
+            WriterContour::Active,
+            WriterOpenIntent::Replacement,
+            2,
+            addr
+        )
+        .await
+        .is_some()
+    );
+    drop(successor);
+    assert_eq!(
+        pool.writer_replacement_open_reserved
+            .load(Ordering::Acquire),
+        0
+    );
+}
+
+#[tokio::test]
+async fn panicking_transport_releases_capacity_after_unwinding_its_resources() {
+    let pool = make_pool().await;
+    let permit = pool
+        .reserve_writer_open(
+            WriterContour::Active,
+            WriterOpenIntent::Replacement,
+            2,
+            "127.0.0.1:443".parse().unwrap(),
+        )
+        .await
+        .unwrap();
+    let destroyed = Arc::new(AtomicBool::new(false));
+    let probe = DestructionProbe {
+        counter: pool.writer_replacement_open_reserved.clone(),
+        destroyed: destroyed.clone(),
+    };
+    let task = WriterTransport::new(
+        Box::pin(async move {
+            let _probe = probe;
+            panic!("injected transport panic");
+        }),
+        permit,
+    );
+    assert!(tokio::spawn(task).await.unwrap_err().is_panic());
+    assert!(destroyed.load(Ordering::Acquire));
+    assert_eq!(
+        pool.writer_replacement_open_reserved
+            .load(Ordering::Acquire),
+        0
+    );
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn racing_commit_and_close_release_each_token_exactly_once() {
+    let pool = make_pool().await;
+    for _ in 0..128 {
+        let permit = pool
+            .reserve_writer_open(
+                WriterContour::Active,
+                WriterOpenIntent::Replacement,
+                2,
+                "127.0.0.1:443".parse().unwrap(),
+            )
+            .await
+            .unwrap();
+        let lifetime = ReplacementHandoff::new();
+        let closing = lifetime.clone();
+        let close = tokio::spawn(async move {
+            tokio::task::yield_now().await;
+            closing.close();
+        });
+        let commit = tokio::spawn(async move {
+            let mut permit = Some(permit);
+            lifetime.commit(&mut permit, || true);
+            drop(permit);
+        });
+        close.await.unwrap();
+        commit.await.unwrap();
+        assert_eq!(
+            pool.writer_replacement_open_reserved
+                .load(Ordering::Acquire),
+            0
+        );
+    }
+}

src/transport/middle_proxy/pool_writer/publication.rs

@@ -11,9 +11,8 @@ impl MePool {
             tx,
             byte_budget,
             task_registration,
-            writer_task,
+            mut writer_task,
             intent,
-            _open_reservation,
         } = prepared;
         let writer_id = writer.id;
         let mut writers = self.writers.write().await;
@@ -22,9 +21,15 @@ impl MePool {
         let contour = self.authorize_writer_publication(&writer, &coordinator)?;
         self.authorize_writer_publication_capacity(&writer, contour, intent, writers.as_slice())?;
         writer.contour.store(contour.as_u8(), Ordering::Release);
-        registry_registration.install(writer_id, tx, byte_budget);
+        registry_registration.install_with_lifetime(
+            writer_id,
+            tx,
+            byte_budget,
+            writer_task.lifetime.clone(),
+        );
         writers.push(writer);
         self.conn_count.fetch_add(1, Ordering::Relaxed);
+        drop(writer_task.opening.take());
         self.lifecycle
             .spawn_registered_writer(task_registration, writer_task);
         drop(coordinator);

src/transport/middle_proxy/pool_writer/recovery_tests.rs

@@ -36,7 +36,7 @@ fn prepared<'a>(
     pool: &'a Arc<MePool>,
     writer: MeWriter,
     intent: WriterOpenIntent,
-    reservation: WriterOpenReservation<'a>,
+    reservation: WriterOpenReservation,
     task_started: Arc<AtomicBool>,
 ) -> PreparedWriter<'a> {
     let cancel = writer.cancel.clone();
@@ -45,12 +45,14 @@ fn prepared<'a>(
         byte_budget: writer.byte_budget.clone(),
         writer,
         task_registration: pool.lifecycle.try_register().unwrap(),
-        writer_task: Box::pin(async move {
-            task_started.store(true, Ordering::Release);
-            cancel.cancelled().await;
-        }),
+        writer_task: WriterTransport::new(
+            Box::pin(async move {
+                task_started.store(true, Ordering::Release);
+                cancel.cancelled().await;
+            }),
+            reservation,
+        ),
         intent,
-        _open_reservation: reservation,
     }
 }
 

src/transport/middle_proxy/pool_writer/replacement.rs

@@ -44,9 +44,8 @@ impl MePool {
             tx,
             byte_budget,
             task_registration,
-            writer_task,
-            intent,
-            _open_reservation,
+            mut writer_task,
+            intent: _,
         } = prepared;
         let replacement_writer_id = writer.id;
         let victim_writer_id = reservation.writer_id();
@@ -57,7 +56,25 @@ impl MePool {
         let mut registry_registration = self.registry.prepare_writer_registration().await;
         let coordinator = self.reinit.coordinator.lock();
         let contour = self.authorize_writer_publication(&writer, &coordinator)?;
-        self.authorize_writer_publication_capacity(&writer, contour, intent, writers.as_slice())?;
+        // Only this victim-backed transaction may replace Active coverage during suppression.
+        let family = if writer.addr.is_ipv4() {
+            crate::network::IpFamily::V4
+        } else {
+            crate::network::IpFamily::V6
+        };
+        let configured = if writer.addr.is_ipv4() {
+            self.decision.ipv4_me
+        } else {
+            self.decision.ipv6_me
+        };
+        if !configured
+            || (contour != WriterContour::Active
+                && self.is_family_temporarily_suppressed(family, Self::now_epoch_secs()))
+        {
+            return Err(ProxyError::Proxy(
+                "ME replacement family lost publication authority".into(),
+            ));
+        }
         writer.contour.store(contour.as_u8(), Ordering::Release);
         let Some(victim_pos) = writers
             .iter()
@@ -73,6 +90,17 @@ impl MePool {
                 "ME replacement victim changed role before commit".into(),
             ));
         }
+        if !matches!(
+            purpose,
+            WriterReplacementPurpose::FloorRebalance { .. }
+                | WriterReplacementPurpose::CoverageTransfer { .. }
+        ) && (expected_victim_role.dc != writer.writer_dc
+            || expected_victim_role.family != family)
+        {
+            return Err(ProxyError::Proxy(
+                "ME replacement purpose cannot move coverage between groups".into(),
+            ));
+        }
         if let WriterReplacementPurpose::FloorRebalance {
             donor_floor,
             receiver_floor,
@@ -122,19 +150,103 @@ impl MePool {
                         }) == receiver_family
                 })
                 .count();
-            if donor_count <= donor_floor || receiver_count >= receiver_floor {
+            let protected_floor = self.required_writers_for_dc_with_floor_mode(
+                endpoint_snapshot
+                    .endpoints_for_dc_family(expected_victim_role.dc, expected_victim_role.family)
+                    .len(),
+                false,
+            );
+            let current_receiver_floor = self.required_writers_for_dc_with_floor_mode(
+                endpoint_snapshot
+                    .endpoints_for_dc_family(writer.writer_dc, receiver_family)
+                    .len(),
+                false,
+            );
+            if donor_count <= donor_floor.max(protected_floor)
+                || receiver_count >= receiver_floor.min(current_receiver_floor)
+            {
                 return Err(ProxyError::Proxy(
                     "ME floor rebalance became unnecessary before commit".into(),
                 ));
             }
         }
-        if !registry_registration.prepare_replacement_commit(reservation) {
+        if let WriterReplacementPurpose::CoverageTransfer {
+            authority,
+            receiver_floor,
+        } = purpose
+        {
+            if authority
+                != (
+                    coordinator.endpoint_revision,
+                    coordinator.floor_policy_revision,
+                )
+                || contour != WriterContour::Active
+                || expected_victim_role.contour != WriterContour::Active
+            {
+                return Err(ProxyError::Proxy(
+                    "ME coverage transfer lost policy authority".into(),
+                ));
+            }
+            let endpoints = self.endpoint_snapshot.load();
+            let count = |dc, family| {
+                writers
+                    .iter()
+                    .filter(|candidate| {
+                        !candidate.draining.load(Ordering::Acquire)
+                            && candidate.generation == coordinator.active_generation
+                            && candidate.writer_dc == dc
+                            && WriterContour::from_u8(candidate.contour.load(Ordering::Acquire))
+                                == WriterContour::Active
+                            && candidate.addr.is_ipv4()
+                                == matches!(family, crate::network::IpFamily::V4)
+                            && endpoints.contains_dc_endpoint(dc, candidate.addr)
+                    })
+                    .count()
+            };
+            let donor_is_current = victim.generation == coordinator.active_generation
+                && endpoints.contains_dc_endpoint(victim.writer_dc, victim.addr);
+            let donor_floor = self.required_writers_for_dc_with_floor_mode(
+                endpoints
+                    .endpoints_for_dc_family(victim.writer_dc, expected_victim_role.family)
+                    .len(),
+                false,
+            );
+            if (donor_is_current
+                && count(victim.writer_dc, expected_victim_role.family) <= donor_floor)
+                || count(writer.writer_dc, family)
+                    >= receiver_floor.min(
+                        self.required_writers_for_dc_with_floor_mode(
+                            endpoints
+                                .endpoints_for_dc_family(writer.writer_dc, family)
+                                .len(),
+                            false,
+                        ),
+                    )
+            {
+                return Err(ProxyError::Proxy(
+                    "ME coverage transfer no longer preserves floors".into(),
+                ));
+            }
+        }
+        let lifetime = registry_registration
+            .writer_lifetime(victim_writer_id)
+            .ok_or_else(|| {
+                ProxyError::Proxy("ME replacement victim transport disappeared".into())
+            })?;
+        if !lifetime.commit(&mut writer_task.opening, || {
+            registry_registration.prepare_replacement_commit(reservation)
+        }) {
             return Err(ProxyError::Proxy(
                 "ME replacement victim became active before commit".into(),
             ));
         }
 
-        registry_registration.install(replacement_writer_id, tx, byte_budget);
+        registry_registration.install_with_lifetime(
+            replacement_writer_id,
+            tx,
+            byte_budget,
+            writer_task.lifetime.clone(),
+        );
         writers.push(writer);
         self.conn_count.fetch_add(1, Ordering::Relaxed);
         writers.publish_current();
@@ -158,6 +270,7 @@ impl MePool {
 
 #[cfg(test)]
 mod tests {
+    mod convergence;
     use std::collections::HashMap;
     use std::net::{IpAddr, Ipv4Addr};
 
@@ -248,14 +361,54 @@ mod tests {
             tx,
             byte_budget,
             task_registration,
-            writer_task: Box::pin(async move {
-                drop(rx);
-            }),
+            writer_task: WriterTransport::new(
+                Box::pin(async move {
+                    drop(rx);
+                }),
+                open_reservation,
+            ),
             intent: WriterOpenIntent::Replacement,
-            _open_reservation: open_reservation,
         }
     }
 
+    #[tokio::test]
+    async fn suppressed_victim_backed_replacement_keeps_coverage() {
+        let pool = make_pool().await;
+        let addr = endpoint(8);
+        pool.update_proxy_maps(HashMap::from([(2, vec![(addr.ip(), addr.port())])]), None)
+            .await;
+        let victim = install_writer(&pool, 8001, 2, addr).await;
+        pool.set_family_runtime_state(
+            crate::network::IpFamily::V4,
+            crate::transport::middle_proxy::pool::MeFamilyRuntimeState::Suppressed,
+            MePool::now_epoch_secs(),
+            MePool::now_epoch_secs() + 3600,
+            5,
+            0,
+        );
+        let mut reservation = pool
+            .registry
+            .try_reserve_writer_replacement(victim.id)
+            .await
+            .unwrap();
+        let prepared = prepared_writer(&pool, 8002, 2, addr).await;
+        pool.publish_prepared_replacement_writer(
+            prepared,
+            WriterRole::from_writer(&victim),
+            WriterReplacementPurpose::IdleRefresh,
+            &mut reservation,
+        )
+        .await
+        .expect("a reserved active victim must remain replaceable during suppression");
+        assert!(victim.draining.load(Ordering::Acquire));
+        assert_eq!(
+            pool.writer_replacement_open_reserved
+                .load(Ordering::Acquire),
+            1,
+            "overlap is owned until the victim transport is destroyed"
+        );
+    }
+
     #[tokio::test]
     async fn replacement_commit_publishes_successor_before_draining_victim() {
         let pool = make_pool().await;

src/transport/middle_proxy/pool_writer/replacement/tests/convergence.rs

@@ -0,0 +1,198 @@
+use super::*;
+use crate::transport::middle_proxy::registry::ConnMeta;
+
+#[tokio::test]
+async fn busy_obsolete_donor_preserves_clients_and_rechecks_policy() {
+    for stale in [false, true] {
+        let pool = make_pool().await;
+        let obsolete = endpoint(21);
+        let receiver = endpoint(22);
+        pool.update_proxy_maps(
+            HashMap::from([(2, vec![(receiver.ip(), receiver.port())])]),
+            None,
+        )
+        .await;
+        let victim = install_writer(&pool, 9001, 1, obsolete).await;
+        let (client, _messages) = pool.registry.register().await;
+        assert!(
+            pool.registry
+                .bind_writer(
+                    client,
+                    victim.id,
+                    ConnMeta {
+                        target_dc: 1,
+                        client_addr: obsolete,
+                        our_addr: obsolete,
+                        proto_flags: 0,
+                    }
+                )
+                .await
+        );
+        let authority = pool.floor_authority();
+        let mut reservation = pool
+            .registry
+            .try_reserve_writer_replacement_preserving_clients(victim.id)
+            .await
+            .unwrap();
+        let prepared = prepared_writer(&pool, 9002, 2, receiver).await;
+        if stale {
+            pool.reinit.coordinator.lock().floor_policy_revision += 1;
+        }
+        let result = pool
+            .publish_prepared_replacement_writer(
+                prepared,
+                WriterRole::from_writer(&victim),
+                WriterReplacementPurpose::CoverageTransfer {
+                    authority,
+                    receiver_floor: pool.required_writers_for_dc(1),
+                },
+                &mut reservation,
+            )
+            .await;
+        assert_eq!(result.is_ok(), !stale);
+        assert_eq!(victim.draining.load(Ordering::Acquire), !stale);
+        assert_eq!(
+            pool.registry.get_writer(client).await.unwrap().writer_id,
+            victim.id
+        );
+        assert_eq!(
+            pool.writer_replacement_open_reserved
+                .load(Ordering::Acquire),
+            usize::from(!stale)
+        );
+    }
+}
+
+#[tokio::test]
+async fn transfer_commit_matches_independent_donor_floor_model() {
+    // The model counts only current endpoints; obsolete sockets contribute no coverage.
+    for obsolete in [false, true] {
+        for donor_delta in [0usize, 1] {
+            for receiver_full in [false, true] {
+                let pool = make_pool().await;
+                let donor = endpoint(31);
+                let receiver = endpoint(32);
+                pool.update_proxy_maps(
+                    HashMap::from([
+                        (1, vec![(donor.ip(), donor.port())]),
+                        (2, vec![(receiver.ip(), receiver.port())]),
+                    ]),
+                    None,
+                )
+                .await;
+                let floor = pool.required_writers_for_dc(1);
+                let mut victim = None;
+                for id in 0..(floor + donor_delta) {
+                    let writer = install_writer(&pool, 10000 + id as u64, 1, donor).await;
+                    if id == 0 {
+                        victim = Some(writer);
+                    }
+                }
+                let mut victim = victim.unwrap();
+                if obsolete {
+                    let mut writers = pool.writers.write().await;
+                    writers
+                        .iter_mut()
+                        .find(|writer| writer.id == victim.id)
+                        .unwrap()
+                        .addr = endpoint(33);
+                    victim.addr = endpoint(33);
+                }
+                if receiver_full {
+                    for id in 0..floor {
+                        install_writer(&pool, 11000 + id as u64, 2, receiver).await;
+                    }
+                }
+                let mut reservation = pool
+                    .registry
+                    .try_reserve_writer_replacement(victim.id)
+                    .await
+                    .unwrap();
+                let prepared = prepared_writer(&pool, 12000, 2, receiver).await;
+                let result = pool
+                    .publish_prepared_replacement_writer(
+                        prepared,
+                        WriterRole::from_writer(&victim),
+                        WriterReplacementPurpose::CoverageTransfer {
+                            authority: pool.floor_authority(),
+                            receiver_floor: floor,
+                        },
+                        &mut reservation,
+                    )
+                    .await;
+                assert_eq!(
+                    result.is_ok(),
+                    !receiver_full && (obsolete || donor_delta > 0),
+                    "obsolete={obsolete}, surplus={donor_delta}, receiver_full={receiver_full}"
+                );
+            }
+        }
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn concurrent_transfers_cannot_overfill_receiver_or_steal_donor_floor() {
+    let pool = make_pool().await;
+    let donor = endpoint(41);
+    let receiver = endpoint(42);
+    pool.update_proxy_maps(
+        HashMap::from([
+            (1, vec![(donor.ip(), donor.port())]),
+            (2, vec![(receiver.ip(), receiver.port())]),
+        ]),
+        None,
+    )
+    .await;
+    pool.set_adaptive_floor_runtime_caps(pool.floor_authority(), 128, 128, 128, 128, 6, 0, 0);
+    let floor = pool.required_writers_for_dc(1);
+    let count = floor + 8;
+    let mut victims = Vec::new();
+    for id in 0..count {
+        victims.push(install_writer(&pool, 20000 + id as u64, 1, donor).await);
+    }
+    let mut tasks = tokio::task::JoinSet::new();
+    for (index, victim) in victims.into_iter().enumerate() {
+        let pool = pool.clone();
+        tasks.spawn(async move {
+            let authority = pool.floor_authority();
+            let mut reservation = pool
+                .registry
+                .try_reserve_writer_replacement(victim.id)
+                .await
+                .unwrap();
+            let prepared = prepared_writer(&pool, 21000 + index as u64, 2, receiver).await;
+            tokio::task::yield_now().await;
+            pool.publish_prepared_replacement_writer(
+                prepared,
+                WriterRole::from_writer(&victim),
+                WriterReplacementPurpose::CoverageTransfer {
+                    authority,
+                    receiver_floor: floor,
+                },
+                &mut reservation,
+            )
+            .await
+            .is_ok()
+        });
+    }
+    let mut committed = 0;
+    while let Some(result) = tasks.join_next().await {
+        committed += usize::from(result.unwrap());
+    }
+    assert_eq!(committed, floor);
+    let writers = pool.writers.read().await;
+    let live = |dc| {
+        writers
+            .iter()
+            .filter(|writer| writer.writer_dc == dc && !writer.draining.load(Ordering::Acquire))
+            .count()
+    };
+    assert_eq!(live(2), floor);
+    assert_eq!(live(1), count - floor);
+    assert!(live(1) >= floor);
+    assert_eq!(
+        pool.writer_replacement_open_reserved
+            .load(Ordering::Acquire),
+        committed
+    );
+}

src/transport/middle_proxy/pool_writer/runtime.rs

@@ -291,9 +291,8 @@ impl MePool {
             tx,
             byte_budget,
             task_registration,
-            writer_task,
+            writer_task: WriterTransport::new(writer_task, writer_open_reservation),
             intent,
-            _open_reservation: writer_open_reservation,
         })
     }
 

src/transport/middle_proxy/registry.rs

@@ -81,6 +81,7 @@ struct WriterRoute {
     tx: mpsc::Sender<WriterCommand>,
     byte_budget: Arc<Semaphore>,
     replacement_state: Arc<AtomicU8>,
+    lifetime: Arc<super::pool_writer::overlap::ReplacementHandoff>,
 }
 
 #[derive(Clone)]

src/transport/middle_proxy/registry/publication.rs

@@ -99,6 +99,34 @@ impl WriterRegistrationGuard<'_> {
         writer_id: u64,
         tx: mpsc::Sender<WriterCommand>,
         byte_budget: Arc<Semaphore>,
+    ) {
+        self.install_with_lifetime(
+            writer_id,
+            tx,
+            byte_budget,
+            super::super::pool_writer::overlap::ReplacementHandoff::new(),
+        );
+    }
+
+    /// Retrieves the physical lifetime while binding ownership fences victim replacement.
+    pub(in crate::transport::middle_proxy) fn writer_lifetime(
+        &self,
+        writer_id: u64,
+    ) -> Option<Arc<super::super::pool_writer::overlap::ReplacementHandoff>> {
+        self.registry
+            .writers
+            .map
+            .get(&writer_id)
+            .map(|route| route.lifetime.clone())
+    }
+
+    /// Publishes a route associated with its transport destruction authority.
+    pub(in crate::transport::middle_proxy) fn install_with_lifetime(
+        &mut self,
+        writer_id: u64,
+        tx: mpsc::Sender<WriterCommand>,
+        byte_budget: Arc<Semaphore>,
+        lifetime: Arc<super::super::pool_writer::overlap::ReplacementHandoff>,
     ) {
         self.binding.conns_for_writer.entry(writer_id).or_default();
         self.registry
@@ -117,6 +145,7 @@ impl WriterRegistrationGuard<'_> {
                 tx,
                 byte_budget,
                 replacement_state: Arc::new(AtomicU8::new(WriterReplacementState::Open as u8)),
+                lifetime,
             },
         );
     }

src/transport/middle_proxy/registry/writer.rs

@@ -415,15 +415,10 @@ impl ConnRegistry {
             .map
             .get(&conn_id)
             .map(|entry| entry.writer_id)?;
-        let writer = self
-            .writers
-            .map
-            .get(&writer_id)
-            .map(|entry| entry.value().clone())?;
-        Some(ConnWriter {
+        self.writers.map.get(&writer_id).map(|entry| ConnWriter {
             writer_id,
-            tx: writer.tx,
-            byte_budget: writer.byte_budget,
+            tx: entry.tx.clone(),
+            byte_budget: entry.byte_budget.clone(),
         })
     }
 
@@ -436,19 +431,12 @@ impl ConnRegistry {
         let hot = self.hot_binding.map.get(&conn_id)?;
         let writer_id = hot.writer_id;
         let meta = hot.meta.clone();
-        let writer = self
-            .writers
-            .map
-            .get(&writer_id)
-            .map(|entry| entry.value().clone())?;
-        Some((
-            ConnWriter {
-                writer_id,
-                tx: writer.tx,
-                byte_budget: writer.byte_budget,
-            },
-            meta,
-        ))
+        let writer = self.writers.map.get(&writer_id).map(|entry| ConnWriter {
+            writer_id,
+            tx: entry.tx.clone(),
+            byte_budget: entry.byte_budget.clone(),
+        })?;
+        Some((writer, meta))
     }
 
     pub async fn active_conn_ids(&self) -> Vec<u64> {

src/transport/middle_proxy/rotation.rs

@@ -9,10 +9,17 @@ use crate::config::ProxyConfig;
 use crate::crypto::SecureRandom;
 
 use super::MePool;
+// Durable scheduler intent is independent of pending generation creation.
+mod objective;
+#[cfg(test)]
+mod retry_tests;
 
+/// External causes that request generation reconciliation.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum MeReinitTrigger {
+    /// The configured rotation interval elapsed.
     Periodic,
+    /// Endpoint authority changed.
     MapChanged,
 }
 
@@ -25,6 +32,7 @@ impl MeReinitTrigger {
     }
 }
 
+/// Coalesces an external request; endpoint epochs independently preserve map-change intent.
 pub fn enqueue_reinit_trigger(tx: &mpsc::Sender<MeReinitTrigger>, trigger: MeReinitTrigger) {
     match tx.try_send(trigger) {
         Ok(()) => {}
@@ -82,6 +90,7 @@ fn trigger_reason(pending: u8) -> &'static str {
     }
 }
 
+/// Retries durable reinitialization objectives until their exact endpoint revision converges.
 pub async fn me_reinit_scheduler(
     pool: Arc<MePool>,
     rng: Arc<SecureRandom>,
@@ -90,9 +99,14 @@ pub async fn me_reinit_scheduler(
     me_ready_tx: watch::Sender<u64>,
 ) {
     info!("ME reinit scheduler started");
-    let mut tasks = JoinSet::<bool>::new();
-    let mut pending = 0u8;
-    let mut pending_deadline = None;
+    let mut tasks = JoinSet::<Option<bool>>::new();
+    let mut owners = std::collections::HashMap::new();
+    let mut objective: Option<objective::RetryObjective> = None;
+    let mut next_id = 1u64;
+    let mut epochs = pool.writer_epoch.subscribe();
+    let mut epoch_open = true;
+    let mut observed_revision = pool.endpoint_snapshot.load().revision;
+    let mut completed_revision = None;
     let mut trigger_channel_open = true;
 
     loop {
@@ -101,73 +115,152 @@ pub async fn me_reinit_scheduler(
         pool.reinit
             .max_concurrency_effective
             .store(max_concurrency, std::sync::atomic::Ordering::Release);
-
-        let pending_ready = pending != 0
-            && pending_deadline.is_none_or(|deadline| deadline <= tokio::time::Instant::now());
-        if pending_ready && tasks.len() < max_concurrency {
-            let reason = trigger_reason(pending);
-            pending = 0;
-            pending_deadline = None;
-            debug!(reason, max_concurrency, "ME reinit scheduled");
+        let snapshot = pool.endpoint_snapshot.load_full();
+        if snapshot.revision != observed_revision {
+            observed_revision = snapshot.revision;
+            objective = Some(objective::RetryObjective::new(
+                next_id,
+                observed_revision,
+                REINIT_TRIGGER_MAP_CHANGED,
+                Duration::from_millis(cfg.general.me_reinit_coalesce_window_ms),
+            ));
+            next_id = next_id.wrapping_add(1);
+        }
+        let owned = objective
+            .as_ref()
+            .is_some_and(|current| owners.values().any(|identity| current.matches(*identity)));
+        if let Some(current) = objective.as_mut()
+            && !owned
+            && current.attempt > 0
+        {
+            let status = pool.reinit.status.load_full();
+            let authority = pool.floor_authority();
+            let readiness = pool.api_hardswap_snapshot().await;
+            // An API projection is usable only while its exact publication and policy survive
+            // the await. A changed snapshot is unknown, not a not-ready transition.
+            if Arc::ptr_eq(&status, &pool.reinit.status.load_full())
+                && authority == pool.floor_authority()
+            {
+                if status.pending_hardswap_endpoint_revision == current.revision
+                    && readiness.pending_map_current == Some(true)
+                    && readiness.pending_writer_deficit == 0
+                {
+                    current.ready((
+                        status.pending_hardswap_generation,
+                        status.pending_hardswap_map_hash,
+                        status.pending_hardswap_endpoint_revision,
+                    ));
+                } else {
+                    current.not_ready();
+                }
+            }
+        }
+        let can_launch = !owned
+            && tasks.len() < max_concurrency
+            && objective
+                .as_ref()
+                .is_some_and(|current| current.attempt == 0 || tasks.is_empty());
+        if can_launch
+            && objective.as_ref().is_some_and(|current| {
+                current
+                    .deadline
+                    .is_some_and(|deadline| deadline <= tokio::time::Instant::now())
+            })
+        {
+            if pool.endpoint_snapshot.load().revision != snapshot.revision {
+                continue;
+            }
+            let Some(current) = objective.as_mut() else {
+                continue;
+            };
+            let identity = (current.id, current.revision);
+            current.deadline = None;
+            debug!(
+                reason = trigger_reason(current.triggers),
+                attempt = current.attempt,
+                endpoint_revision = current.revision,
+                "ME reinit scheduled"
+            );
             let pool_clone = pool.clone();
             let rng_clone = rng.clone();
             pool.reinit
                 .scheduler_inflight
                 .fetch_add(1, std::sync::atomic::Ordering::AcqRel);
             let inflight = ReinitInflightGuard {
-                pool: Arc::clone(&pool_clone),
+                pool: pool_clone.clone(),
             };
-            tasks.spawn(async move {
+            let future = async move {
                 let _inflight = inflight;
                 pool_clone
-                    .zero_downtime_reinit_periodic(rng_clone.as_ref())
+                    .reinit_endpoint_snapshot(rng_clone.as_ref(), snapshot)
                     .await
-            });
+            };
+            // Pool shutdown joins destruction of attempts as well as their writer transports.
+            let Ok(tracked) = pool.lifecycle.track_producer(future) else {
+                return;
+            };
+            let task = tasks.spawn(tracked);
+            owners.insert(task.id(), identity);
             continue;
         }
-
-        if !trigger_channel_open && pending == 0 && tasks.is_empty() {
-            warn!("ME reinit scheduler stopped: trigger channel closed");
+        if !trigger_channel_open && objective.is_none() && tasks.is_empty() {
             return;
         }
-
-        let timer_enabled = pending != 0 && tasks.len() < max_concurrency;
+        let deadline = objective.as_ref().and_then(|current| current.deadline);
         tokio::select! {
             trigger = trigger_rx.recv(), if trigger_channel_open => {
                 match trigger {
                     Some(trigger) => {
-                        if pending == 0 {
-                            pending_deadline = Some(
-                                tokio::time::Instant::now()
-                                    + Duration::from_millis(
-                                        cfg.general.me_reinit_coalesce_window_ms,
-                                    ),
-                            );
+                        let revision = pool.endpoint_snapshot.load().revision;
+                        if trigger == MeReinitTrigger::MapChanged && completed_revision == Some(revision) {
+                            continue;
                         }
-                        pending |= trigger_bit(trigger);
+                        if let Some(current) = objective.as_mut()
+                            && current.revision == revision
+                            && (trigger == MeReinitTrigger::MapChanged
+                                || !owners.values().any(|identity| current.matches(*identity))) {
+                            // Endpoint epochs and updater notifications describe the same objective.
+                            current.triggers |= trigger_bit(trigger);
+                        } else {
+                            objective = Some(objective::RetryObjective::new(next_id, revision,
+                                trigger_bit(trigger), Duration::from_millis(cfg.general.me_reinit_coalesce_window_ms)));
+                            next_id = next_id.wrapping_add(1);
+                        }
+                        observed_revision = revision;
                     }
                     None => trigger_channel_open = false,
                 }
             }
-            joined = tasks.join_next(), if !tasks.is_empty() => {
-                match joined {
-                    Some(Ok(true)) => {
-                        me_ready_tx.send_modify(|version| {
-                            *version = version.saturating_add(1);
-                        });
-                    }
-                    Some(Ok(false)) => {}
-                    Some(Err(error)) => {
+            changed = epochs.changed(), if epoch_open => {
+                if changed.is_err() { epoch_open = false; }
+            }
+            joined = tasks.join_next_with_id(), if !tasks.is_empty() => {
+                let Some(joined) = joined else { continue; };
+                let (id, succeeded) = match joined {
+                    Ok((id, Some(succeeded))) => (id, succeeded),
+                    Ok((_, None)) => return,
+                    Err(error) => {
                         warn!(error = %error, "ME reinit task failed");
+                        (error.id(), false)
+                    }
+                };
+                let Some(identity) = owners.remove(&id) else { continue; };
+                if succeeded {
+                    me_ready_tx.send_modify(|version| *version = version.saturating_add(1));
+                }
+                if let Some(current) = objective.as_mut()
+                    && current.matches(identity) {
+                    if succeeded {
+                        completed_revision = Some(current.revision);
+                        objective = None;
+                    } else {
+                        current.failed(Duration::from_millis(pool.hardswap_warmup_backoff_ms(current.attempt)));
                     }
-                    None => {}
                 }
             }
             _ = async {
-                if let Some(deadline) = pending_deadline {
-                    tokio::time::sleep_until(deadline).await;
-                }
-            }, if timer_enabled => {}
+                if let Some(deadline) = deadline { tokio::time::sleep_until(deadline).await; }
+            }, if can_launch && deadline.is_some() => {}
         }
     }
 }

src/transport/middle_proxy/rotation/objective.rs

@@ -0,0 +1,55 @@
+use std::time::Duration;
+use tokio::time::Instant;
+
+/// Durable intent exists even if a reinit returns before creating a pending generation.
+pub(super) struct RetryObjective {
+    /// Distinguishes separate external requests for the same endpoint revision.
+    pub(super) id: u64,
+    /// Exact endpoint snapshot to reconcile.
+    pub(super) revision: u64,
+    /// Coalesced external causes used for diagnostic logging.
+    pub(super) triggers: u8,
+    /// Completed failures; the count saturates but never terminates recovery.
+    pub(super) attempt: usize,
+    /// A missing deadline means the objective currently owns a running task.
+    pub(super) deadline: Option<Instant>,
+    ready_wake: Option<(u64, u64, u64)>,
+}
+
+impl RetryObjective {
+    /// Creates retryable intent before any asynchronous attempt can fail.
+    pub(super) fn new(id: u64, revision: u64, triggers: u8, delay: Duration) -> Self {
+        Self {
+            id,
+            revision,
+            triggers,
+            attempt: 0,
+            deadline: Some(Instant::now() + delay),
+            ready_wake: None,
+        }
+    }
+
+    /// Rejects completions from superseded objectives, including the same endpoint revision.
+    pub(super) fn matches(&self, identity: (u64, u64)) -> bool {
+        (self.id, self.revision) == identity
+    }
+
+    /// Measures backoff from completion and never caps the number of retry attempts.
+    pub(super) fn failed(&mut self, delay: Duration) {
+        self.attempt = self.attempt.saturating_add(1);
+        self.deadline = Some(Instant::now() + delay);
+    }
+
+    /// Accelerates once per observed ready tuple without allowing an epoch storm to spin.
+    pub(super) fn ready(&mut self, key: (u64, u64, u64)) {
+        if self.ready_wake != Some(key) {
+            self.ready_wake = Some(key);
+            self.deadline = Some(Instant::now());
+        }
+    }
+
+    /// Re-arms acceleration only after a coherent observation of lost readiness.
+    pub(super) fn not_ready(&mut self) {
+        self.ready_wake = None;
+    }
+}

src/transport/middle_proxy/rotation/retry_tests.rs

@@ -0,0 +1,188 @@
+use super::objective::RetryObjective;
+use super::*;
+
+#[tokio::test(start_paused = true)]
+async fn retry_objective_survives_unlimited_failures_and_ready_storms() {
+    let mut objective = RetryObjective::new(1, 2, REINIT_TRIGGER_PERIODIC, Duration::ZERO);
+    assert!(objective.deadline.is_some());
+    for _ in 0..100 {
+        objective.deadline = None;
+        tokio::time::advance(Duration::from_secs(70)).await;
+        let completed = tokio::time::Instant::now();
+        objective.failed(Duration::from_secs(30));
+        assert_eq!(
+            objective.deadline,
+            Some(completed + Duration::from_secs(30))
+        );
+    }
+    objective.ready((3, 4, 2));
+    objective.failed(Duration::from_secs(30));
+    let deadline = objective.deadline;
+    for _ in 0..100 {
+        objective.ready((3, 4, 2));
+    }
+    assert_eq!(objective.deadline, deadline);
+    objective.not_ready();
+    objective.ready((3, 4, 2));
+    assert!(
+        objective.deadline < deadline,
+        "a genuine loss and recovery of the same floor re-arms wakeup"
+    );
+    assert!(!objective.matches((1, 1)));
+    assert!(!objective.matches((2, 2)));
+}
+
+#[tokio::test]
+async fn pre_pending_failure_remains_live_without_a_periodic_trigger() {
+    let pool = crate::transport::middle_proxy::pool_writer_security_tests::make_pool().await;
+    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let addr = listener.local_addr().unwrap();
+    pool.update_proxy_maps(
+        std::collections::HashMap::from([(2, vec![(addr.ip(), addr.port())])]),
+        None,
+    )
+    .await;
+    pool.set_family_runtime_state(
+        crate::network::IpFamily::V4,
+        crate::transport::middle_proxy::pool::MeFamilyRuntimeState::Suppressed,
+        MePool::now_epoch_secs(),
+        MePool::now_epoch_secs() + 3600,
+        5,
+        0,
+    );
+    pool.reinit
+        .me_hardswap_warmup_pass_backoff_base_ms
+        .store(10, std::sync::atomic::Ordering::Relaxed);
+    pool.reinit
+        .me_hardswap_warmup_delay_min_ms
+        .store(0, std::sync::atomic::Ordering::Relaxed);
+    pool.reinit
+        .me_hardswap_warmup_delay_max_ms
+        .store(0, std::sync::atomic::Ordering::Relaxed);
+    let mut config = ProxyConfig::default();
+    config.general.me_reinit_coalesce_window_ms = 0;
+    let (_config_tx, config_rx) = watch::channel(Arc::new(config));
+    let (tx, rx) = mpsc::channel(1);
+    let (ready_tx, _) = watch::channel(0);
+    tx.send(MeReinitTrigger::Periodic).await.unwrap();
+    drop(tx);
+    let scheduler = tokio::spawn(me_reinit_scheduler(
+        pool.clone(),
+        pool.rng.clone(),
+        config_rx,
+        rx,
+        ready_tx,
+    ));
+    tokio::time::sleep(Duration::from_millis(50)).await;
+    assert!(
+        !scheduler.is_finished(),
+        "false before pending creation must not discard recovery intent"
+    );
+    assert!(pool.reinit.coordinator.lock().pending.is_none());
+    // Family policy changes do not emit endpoint or writer epochs.
+    pool.set_family_runtime_state(
+        crate::network::IpFamily::V4,
+        crate::transport::middle_proxy::pool::MeFamilyRuntimeState::Healthy,
+        MePool::now_epoch_secs(),
+        0,
+        0,
+        0,
+    );
+    let (stream, _) = tokio::time::timeout(Duration::from_secs(2), listener.accept())
+        .await
+        .expect("autonomous retry must actually reach TCP without another trigger")
+        .unwrap();
+    assert!(pool.shutdown_until(Duration::from_secs(1)).await);
+    tokio::time::timeout(Duration::from_secs(1), scheduler)
+        .await
+        .unwrap()
+        .unwrap();
+    assert_eq!(
+        pool.reinit
+            .scheduler_inflight
+            .load(std::sync::atomic::Ordering::Acquire),
+        0
+    );
+    drop(stream);
+}
+
+#[tokio::test]
+async fn panic_retains_the_task_identity_for_retry() {
+    let mut tasks = JoinSet::<bool>::new();
+    let id = tasks.spawn(async { panic!("injected reinit panic") }).id();
+    let error = tasks.join_next_with_id().await.unwrap().unwrap_err();
+    assert_eq!(error.id(), id);
+}
+
+async fn check_inflight_trigger(trigger: MeReinitTrigger, starts_successor: bool) {
+    let pool = crate::transport::middle_proxy::pool_writer_security_tests::make_pool().await;
+    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let addr = listener.local_addr().unwrap();
+    pool.update_proxy_maps(
+        std::collections::HashMap::from([(2, vec![(addr.ip(), addr.port())])]),
+        None,
+    )
+    .await;
+    pool.reinit
+        .me_hardswap_warmup_delay_min_ms
+        .store(0, std::sync::atomic::Ordering::Relaxed);
+    pool.reinit
+        .me_hardswap_warmup_delay_max_ms
+        .store(0, std::sync::atomic::Ordering::Relaxed);
+    let mut config = ProxyConfig::default();
+    config.general.me_reinit_coalesce_window_ms = 0;
+    config.general.me_reinit_singleflight = false;
+    config.general.me_reinit_max_concurrency = 2;
+    let (_config_tx, config_rx) = watch::channel(Arc::new(config));
+    let (tx, rx) = mpsc::channel(1);
+    let (ready_tx, _) = watch::channel(0);
+    tx.send(MeReinitTrigger::MapChanged).await.unwrap();
+    let scheduler = tokio::spawn(me_reinit_scheduler(
+        pool.clone(),
+        pool.rng.clone(),
+        config_rx,
+        rx,
+        ready_tx,
+    ));
+    let (first, _) = tokio::time::timeout(Duration::from_secs(1), listener.accept())
+        .await
+        .unwrap()
+        .unwrap();
+    assert_eq!(
+        pool.reinit
+            .scheduler_inflight
+            .load(std::sync::atomic::Ordering::Acquire),
+        1
+    );
+    // Keep the first attempt blocked before handshake completion while delivering another trigger.
+    tx.send(trigger).await.unwrap();
+    let successor = tokio::time::timeout(Duration::from_millis(100), listener.accept()).await;
+    let inflight = pool
+        .reinit
+        .scheduler_inflight
+        .load(std::sync::atomic::Ordering::Acquire);
+    assert!(pool.shutdown_until(Duration::from_secs(1)).await);
+    tokio::time::timeout(Duration::from_secs(1), scheduler)
+        .await
+        .unwrap()
+        .unwrap();
+    assert_eq!(successor.is_ok(), starts_successor);
+    assert_eq!(inflight, if starts_successor { 2 } else { 1 });
+    assert_eq!(
+        pool.reinit
+            .scheduler_inflight
+            .load(std::sync::atomic::Ordering::Acquire),
+        0
+    );
+    drop(first);
+}
+
+#[tokio::test]
+async fn duplicate_map_change_coalesces_with_its_inflight_revision() {
+    check_inflight_trigger(MeReinitTrigger::MapChanged, false).await;
+}
+
+#[tokio::test]
+async fn periodic_trigger_retains_successor_intent_while_map_change_runs() {
+    check_inflight_trigger(MeReinitTrigger::Periodic, true).await;
+}

src/web/http/decoy.rs

@@ -345,6 +345,10 @@ fn remove_hop_by_hop(headers: &mut hyper::HeaderMap) {
     }
 }
 
+#[cfg(test)]
+#[path = "decoy_dns_tests.rs"]
+mod decoy_dns_tests;
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/web/http/decoy_dns_tests.rs

@@ -0,0 +1,55 @@
+use super::*;
+
+use arc_swap::ArcSwap;
+use std::sync::Arc;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpListener;
+
+use crate::config::WebCarrier;
+use crate::maestro::generation::test_runtime_generation;
+use crate::web::http::tests::{request, runtime_config};
+
+#[tokio::test]
+async fn decoy_dns_pinned_socket_keeps_configured_hostname_in_actual_http_request() {
+    let origin = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let mut config = runtime_config([17; 32], WebCarrier::Https);
+    let snapshot = Arc::get_mut(config.web.runtime.as_mut().unwrap()).unwrap();
+    let vhost = Arc::get_mut(snapshot.vhosts.get_mut("proxy.example.com").unwrap()).unwrap();
+    // A public hostname deliberately paired with a loopback socket proves no request-time lookup.
+    vhost.decoy = WebRuntimeDecoy::HttpUpstream {
+        addr: origin.local_addr().unwrap(),
+        authority: "bsi.bund.de:8080".to_string(),
+    };
+    let generation = test_runtime_generation(1, config);
+    let runtime = WebProcessRuntime::start(Arc::new(ArcSwap::from(generation.clone())));
+    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let receive = async {
+        let (mut socket, _) = origin.accept().await.unwrap();
+        let mut bytes = Vec::new();
+        let mut buf = [0; 1024];
+        while !bytes.windows(4).any(|part| part == b"\r\n\r\n") {
+            let count = socket.read(&mut buf).await.unwrap();
+            assert_ne!(count, 0);
+            bytes.extend_from_slice(&buf[..count]);
+        }
+        socket
+            .write_all(b"HTTP/1.1 200 OK\r\nContent-Length: 2\r\nConnection: close\r\n\r\nOK")
+            .await
+            .unwrap();
+        String::from_utf8(bytes).unwrap()
+    };
+    let (response, upstream) = tokio::time::timeout(std::time::Duration::from_secs(5), async {
+        tokio::join!(request(&listener, &runtime, b"GET /site?q=1 HTTP/1.1\r\nHost: proxy.example.com\r\nX-Forwarded-For: 192.0.2.10\r\nConnection: close\r\n\r\n".to_vec()), receive)
+    }).await.unwrap();
+    assert!(upstream.starts_with("GET /site?q=1 HTTP/1.1\r\n"));
+    assert!(
+        upstream
+            .to_ascii_lowercase()
+            .contains("\r\nhost: bsi.bund.de:8080\r\n")
+    );
+    assert!(response.starts_with(b"HTTP/1.1 200"));
+    assert!(response.ends_with(b"OK"));
+    runtime.shutdown().await;
+    generation.stop_sessions().await;
+    generation.stop_background_tasks().await;
+}