Commit Graph

4 Commits

Author SHA1 Message Date
Feng Ruohang b8ebaffd2e fix(restore): name the server that keeps native restore unavailable
The native restore gate refused a POST restore and a queued restore
with one message, "unavailable during a rolling upgrade: not every
server of the cluster supports it yet", whether a server answered
another protocol or was simply not connected. A cluster with one server
down thus reported a rolling upgrade, and the operator looked for an
older binary instead of the server.

The gate now returns an error that wraps errNativeRestoreUnavailable
and says why: errNativeRestorePeerUnreachable names the server that is
not connected ("server host:port is not reachable, so it cannot be
shown to have stopped an older restore"), errNativeRestoreUnsupported
keeps the rolling-upgrade text for a server that reports another
protocol or reconnected while it was asked, and a check that its
deadline ended carries that error. The POST handler maps the error to
503 ServiceUnavailable with the message as before, the worker still
clears its marker and stops, and errors.Is(err,
errNativeRestoreUnavailable) holds for every refusal. The gate remains
closed in every case it was closed before.

TestNativeRestoreRefusalReasons posts a restore with a fake server that
is not connected and one that answers protocol 1; before this change
the first answered 503 with the rolling-upgrade text and without "not
reachable".

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Signed-off-by: Feng Ruohang <rh@vonng.com>
2026-11-07 17:04:02 +08:00
Feng Ruohang 3268fbea7e fix(restore): queue the heal of a partial commit under the normalized ID
A native restore commit that reaches a write quorum but not every drive
queues an MRF heal of the version. It passed the raw version ID, which is
empty for the null version, while the convergence path passes the
normalized "null". The heal boundary already reads an empty ID as the
null version, so the old entry healed the right version; this makes the
two paths queue the same identity.

The header of restore-capability.go still described the multipart upload
of the first native-restore design. It now describes what the capability
gate protects in the two-phase design: restore ownership through the
restore lock and the attempt marker, the staged commit under the object
lock, and the attempt fence. It also says why an unreachable server
blocks native restore: it is not proven stopped.

Test: TestRestorePartialCommitQueuesNullVersionHeal fails one drive's
commit on a noncurrent null version, checks the queued entry names
"null", and heals it back onto that drive. It fails on the base at the
identity check only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Feng Ruohang <rh@vonng.com>
2026-11-06 19:40:24 +08:00
Feng Ruohang 45b1e4bc00 fix(restore): stage native restores outside the object lock
The unreleased native-restore fixes after RELEASE.2026-10-26T00-00-00Z
let the lock decide who owns a restore. Since fa42a0982 a single-pool
worker holds the object lock for the whole tier download, and since
7f38bf628 a busy lock means "a restore runs". 7f38bf628 also keeps the
restore's data in a marked multipart upload. Two regressions followed:

- While an old version restored, every GET, HEAD and write of the same
  key waited for the download. On a single pool this is new; with
  several pools the released code already held the lock that long.
- An ordinary upload whose completion failed after staging its metadata
  became InvalidUploadID for every caller, and could not be aborted for
  an hour. The marker that hid restore uploads could not tell them apart
  once a completion had rewritten the upload's xl.meta.

A restore now runs in two phases:

- The worker erasure-codes the tier copy into the tmp volume of the
  version's set, without the object lock, as heal does. A drive that
  fails any part, or misses a part when CheckParts runs before the
  commit, takes no part in the commit.
- A restore lock per version tells whether a restore runs. POST takes it
  before the object lock and hands it to the worker. It is a liveness
  hint: only the checks under the object lock decide what is written.
- The commit takes the object lock briefly, on one pool or several. It
  reads the version again and checks the attempt's ownership, the
  version identity, the tier copy, the part layout and the erasure
  layout. It then publishes with RenameData drive by drive, never
  through erasure renameData's undo, and needs the write quorum. The
  replaced data directory goes only when every published drive reports
  the same one.
- A publication that reached some drives but not the write quorum
  converges under the same lock hold, in bounded retries after it: back
  to the unrestored version on every drive that holds it, or to a
  committed restore when the copy turns out to be on a write quorum.
  Each pass first checks that every drive holds what the version held
  before the commit, the commit wrote, or a convergence wrote, and stops
  on anything else. It deletes no directory.

Multipart goes back to main: erasure-multipart.go and
bucket-object-lock.go are identical to 69fcf50cd. The commit lock, the
marker and the restore exceptions of multipart completion and of the
null-version Object Lock check are gone, and single-pool completion
again takes the upload lock first and the object lock right before it
commits. With several pools, abandoned-data cleanup now takes the pools
lock that writes take, as heal does, so it cannot remove a directory
that a commit moved in place and has not yet referenced. The restore
capability becomes protocol 2, and a queued worker checks it again.

Recovery after a coordinator crash during publication, and storage RPCs
that complete after their caller returned, stay excluded. Main has the
same exposure, and they are tracked separately.

Tests:
- New regression tests cover both problems. They fail on f85d4a5fa,
  and the multipart one also passes on main.
- Fault-injection tests cover a publication below the write quorum,
  including seven of twelve drives on 8+4; lost answers; convergence
  retries and stops; the old data directory; a stale inline marker; a
  recreated tmp volume; a published revision read across its expiry; a
  second POST; a target deleted during the download; a tier 404; and
  pools-locked abandoned cleanup.
- Thirteen tests of the upload marker from 7f38bf628 are dropped, and
  so is TestNativeRestoreConcurrentCompletion from fa42a0982, which
  completed the restore's upload from a client. Four tests are reframed
  for the new semantics, including the lock-domain restore test, which
  now gates the commit.
- Three self-recursive WriteMetadata test doubles are fixed, and the
  helpers of the dropped tests are removed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Feng Ruohang <rh@vonng.com>
2026-11-06 11:30:29 +08:00
Feng Ruohang 7f38bf6282 fix(restore): give each native restore an owner and a private upload
A native restore (POST ?restore, issue #281) marks the version ongoing,
and a background worker rehydrates it from the tier. The worker, its
upload and every status write could be reached or confused by other
callers. A public client could write into or complete the restore
upload. POST copied a whole metadata snapshot over newer protection
changes. An old or failed attempt could act on a newer one. Restore,
expiry and heal decided on whichever drive's metadata they read.

Each POST that starts a rehydration now writes an attempt ID into the
version's internal metadata, with the identity it resolved: version
ID, ETag, size and ModTime. The worker, its upload, its part writes and
its completion carry the attempt. A worker whose attempt no longer
owns the version stops without writing, completing or resetting. Every
write uses the versioning state and explicit version ID captured by
POST, so a null target stays null.

The restore upload carries an internal marker, decided over all drives.
Public multipart calls answer NoSuchUpload and listings hide it. An
unknown marker fails closed. A completion holds a commit lock from
staging its commit in the upload until the commit ends. Stale cleanup
decides on every upload past the stale age under that lock, and keeps
it until its rename ends, also past the drive deadline. Abort of a
committing upload takes the lock and removes a failed commit's
leftover only when every copy is staged and older than one hour.

POST, the worker, the reset, the ExpireRestored recheck and heal all
decide on the authoritative revision of the exact version. That is the
revision held by max(n/2+1, read quorum) drives, identified by the
version header and the normalized metadata digest. Status writes patch
only the restore fields of that revision. They write only the drives
that hold it, and put the old revision back on failure. Heal copies
restore fields only when a quorum holds the same fields.

A failed attempt resets itself with bounded in-memory retries. A later
POST takes over a stranded marker when no attempt runs. Otherwise it
answers RestoreAlreadyInProgress within a few seconds.

Older nodes do not know the marker. A new grid capability handler lets
the serving node ask every peer. POST answers 503 ServiceUnavailable
and writes nothing until all peers support native restore, and a
queued worker asks again before it creates its upload.

The single-pool lock-domain split between DELETE/CopyObject and restore
is closed by its own fix, which this change depends on.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Feng Ruohang <rh@vonng.com>
2026-11-05 06:47:38 +08:00