mirror of
https://github.com/seaweedfs/seaweedfs.git
synced 2026-05-25 11:10:20 +00:00
f18ff58476
This fix addresses the root cause of the 28% message loss detected during consumer group rebalancing with 2 consumers: CHANGES: 1. **OffsetCommit**: Don't silently ignore SMQ persistence errors - Previously, if offset persistence to SMQ failed, we'd continue anyway - Now we return an error code so client knows offset wasn't persisted - This prevents silent data loss during rebalancing 2. **OffsetFetch**: Add retry logic with exponential backoff - During rebalancing, brief race condition between commit and persistence - Retry offset fetch up to 3 times with 5-10ms delays - Ensures we get the latest committed offset even during rebalances 3. **Enhanced Logging**: Critical errors now logged at ERROR level - SMQ persistence failures are logged as CRITICAL with detailed context - Helps diagnose similar issues in production ROOT CAUSE: When rebalancing occurs, consumers query OffsetFetch for their next offset. If that offset was just committed but not yet persisted to SMQ, the query would return -1 (not found), causing the consumer to start from offset 0. This skipped messages 76-765 that were already consumed before rebalancing. IMPACT: - Fixes message loss during normal rebalancing operations - Ensures offset persistence is mandatory, not optional - Addresses the 28% data loss detected in comprehensive load tests TESTING: - Single consumer test should show 0 missing (unchanged) - Dual consumer test should show 0 missing (was 3,413 missing) - Rebalancing no longer causes offset gaps