Concurrency/lifecycle (P1, highest-value):
- singleton_resources.go: RegisterBackgroundTask now REPLACES a stopped
task instead of reusing it. BackgroundTask.Start is sync.Once-guarded,
so a task stopped on instance close and re-registered (Traefik
close+recreate for the same provider) was permanently dead: IsTaskRunning
returned false (started && !stopped) so callers retried a start that
was a no-op. Metadata refresh, token cleanup, and health checks now
resume across a recreate cycle.
- error_recovery.go: the shared graceful-degradation health task was
bound to the FIRST instance's performHealthChecks (later instances'
checks never ran) and any instance's Close stopped it for all. Added a
global live-instance registry; the shared task runs every instance's
checks and is stopped only when the last instance closes (mirrors the
singleton-token-cleanup gate).
Storage/cache:
- hybrid.go recordL2Error: Store(now) then immediately compared
time.Since(t)<1s against its own write => ALWAYS fired, so a single
transient L2 error flipped the whole cache into fallback (full L2
bypass -> upstream stampede). Now enters fallback only on a PRIOR
error within the window (true "multiple errors"). Updated two tests
that had encoded the old single-error-fallback bug.
- redis_pool.go: ConnectionPool.Put checked closed but sent on
p.connections without holding p.mu; Close closed it under p.mu.
Window => 'send on closed channel' panic at shutdown. Put now holds
p.mu (the lock only Close used).
HTTP/transport:
- jwk.go fetchJWKS: added an explicit >1 MiB guard (was silent partial
read, could yield a truncated keyset and spurious missing-kid).
- http_client_pool.go configKey: now includes every transport-behavior
field it actually consumes (compression, HTTP2, keep-alives, timeouts,
buffer sizes, dial) so behaviorally different configs no longer share
one transport built with the first config's settings.
Each fix has a regression test. Verified: full source-order suite green,
golangci-lint 0 issues, 3x full -race -count=1 -shuffle=on ./... all exit 0.
