[PR] [fluss-server] Fix replicasOnOffline deadlock with enhanced diagnostics [fluss]

["platinumhamburg (via GitHub)" <gi...@apache.org>]

platinumhamburg opened a new pull request, #3012:
URL: https://github.com/apache/fluss/pull/3012

   Root cause: ReplicaManager.addFetcherForReplicas() misclassified "no leader" (leaderId=null) as a STORAGE_EXCEPTION, which triggered permanent offline marking via replicasOnOffline. Once a replica was marked offline, it was excluded from liveReplicas during election, causing the bucket to remain leaderless indefinitely.
   
   Fix: Replace the error branch with a simple guard (leaderId != null && leaderId >= 0) that skips fetcher setup for replicas without a valid leader, allowing them to recover naturally on the next LeaderAndIsr notification.
   
   Additional improvements:
   - Enhanced initCoordinatorContext logging with server load stats and skip reasons (null registration, missing endpoint)
   - Added diagnostic logging when ISR members are excluded from liveReplicas during election
   - Added warn logging for NotifyLeaderAndIsr failures before marking replicas offline
   - Extracted electAndNotifyForBucket() to reduce duplication in TableBucketStateMachine state transitions
   - Added CoordinatorContext.isReplicaInOfflineSet() for diagnostics
   
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Re: [PR] [fluss-server] Fix replicasOnOffline deadlock with enhanced diagnostics [fluss]

["platinumhamburg (via GitHub)" <gi...@apache.org>]

platinumhamburg closed pull request #3012: [fluss-server] Fix replicasOnOffline deadlock with enhanced diagnostics
URL: https://github.com/apache/fluss/pull/3012


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