databendlabs / openraft / 28994232970

87%

Build Type

push

github

Committed by drmingdrmer

Commit Message

fix: reject stale replication acks after log reversion

# Summary

In pipeline (`LogsSince`) mode many acks share one `InflightId`, so a log
reversion can clear the inflight to `None` while acks queued before the
reset are still arriving. Acting on such stale signals is unsafe: advancing
the follower's matched index over logs it has reverted could form a false
quorum, and re-reading an already-consumed command would replay an
acknowledged payload. Both are now suppressed.

# Details

- `Inflight::ack()` returns whether the ack matched the live request. A
  stale ack -- mismatched `InflightId`, or `Inflight::None` after a reversion
  cleared it -- now returns `false` instead of hitting `unreachable!`, and
  the progress updater skips advancing `matching` for it.
- Replication reads of the replicate and committed watch channels switch to
  `borrow_and_update()`, marking the value seen so a notification still
  pending after `changed()` resolves does not deliver and replay the same
  command twice.
- Add a test that acking a cleared (`None`) inflight is reported stale and
  leaves the inflight untouched.

Coverage Stats

13 of 14 new or added lines in 4 files covered. (92.86%)

297 existing lines in 2 files now uncovered.

17427 of 19989 relevant lines covered (87.18%)

158535.94 hits per line