fix: limit HTTP transport tuables to affordable values (#9383)

Close connections pro-actively in transient calls

cmd/admin-handlers.go

@@ -986,7 +986,7 @@ func (a adminAPIHandlers) TraceHandler(w http.ResponseWriter, r *http.Request) {
 	// Use buffered channel to take care of burst sends or slow w.Write()
 	traceCh := make(chan interface{}, 4000)
 
-	peers := getRestClients(globalEndpoints)
+	peers := newPeerRestClients(globalEndpoints)
 
 	globalHTTPTrace.Subscribe(traceCh, ctx.Done(), func(entry interface{}) bool {
 		return mustTrace(entry, trcAll, trcErr)
@@ -1051,7 +1051,7 @@ func (a adminAPIHandlers) ConsoleLogHandler(w http.ResponseWriter, r *http.Reque
 
 	logCh := make(chan interface{}, 4000)
 
-	peers := getRestClients(globalEndpoints)
+	peers := newPeerRestClients(globalEndpoints)
 
 	globalConsoleSys.Subscribe(logCh, ctx.Done(), node, limitLines, logKind, nil)
 
@@ -1482,7 +1482,9 @@ func (a adminAPIHandlers) ServerInfoHandler(w http.ResponseWriter, r *http.Reque
 func fetchLambdaInfo(cfg config.Config) []map[string][]madmin.TargetIDStatus {
 
 	// Fetch the configured targets
-	targetList, err := notify.FetchRegisteredTargets(cfg, GlobalContext.Done(), NewGatewayHTTPTransport(), true, false)
+	tr := NewGatewayHTTPTransport()
+	defer tr.CloseIdleConnections()
+	targetList, err := notify.FetchRegisteredTargets(cfg, GlobalContext.Done(), tr, true, false)
 	if err != nil && err != notify.ErrTargetsOffline {
 		logger.LogIf(GlobalContext, err)
 		return nil
@@ -1605,12 +1607,8 @@ func checkConnection(endpointStr string, timeout time.Duration) error {
 		return pErr
 	}
 
-	tr := newCustomHTTPTransport(
-		&tls.Config{RootCAs: globalRootCAs},
-		timeout,
-		0, /* Default value */
-	)()
-
+	tr := newCustomHTTPTransport(&tls.Config{RootCAs: globalRootCAs}, timeout)()
+	defer tr.CloseIdleConnections()
 	if dErr := u.DialHTTP(tr); dErr != nil {
 		if urlErr, ok := dErr.(*url.Error); ok {
 			// To treat "connection refused" errors as un reachable endpoint.