backend/retry: don't trip circuit breaker if context is canceled

When the context used for a load operation is canceled, then the result
is always an error independent of whether the file could be retrieved
from the backend. Do not false positively trip the circuit breaker in
this case.

The old behavior was problematic when trying to lock a repository. When
`Lock.checkForOtherLocks` listed multiple lock files in parallel and one
of them fails to load, then all other loads were canceled. This
cancelation was remembered by the circuit breaker, such that locking
retries would fail.
This commit is contained in:
Michael Eischer 2024-08-22 23:16:12 +02:00
parent a99b824508
commit 8206cd19c8
3 changed files with 37 additions and 2 deletions

View file

@ -209,9 +209,10 @@ func (be *Backend) Load(ctx context.Context, h backend.Handle, length int, offse
return be.Backend.Load(ctx, h, length, offset, consumer)
})
if feature.Flag.Enabled(feature.BackendErrorRedesign) && err != nil && !be.IsPermanentError(err) {
if feature.Flag.Enabled(feature.BackendErrorRedesign) && err != nil && ctx.Err() == nil && !be.IsPermanentError(err) {
// We've exhausted the retries, the file is likely inaccessible. By excluding permanent
// errors, not found or truncated files are not recorded.
// errors, not found or truncated files are not recorded. Also ignore errors if the context
// was canceled.
be.failedLoads.LoadOrStore(key, time.Now())
}