# org.apache.kafka.common.errors.InvalidCommitOffsetSyncException: Offset commit failed due to synchronization conflict with the group coordinator

- **ID:** `kafka/invalid-commit-offset-sync`
- **Domain:** kafka
- **Category:** runtime_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The consumer attempted to commit offsets while the group coordinator was in the middle of a rebalance or epoch change, causing a synchronization mismatch.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| kafka 3.4.0 | active | — | — |
| kafka 3.5.0 | active | — | — |
| kafka 3.6.0 | active | — | — |

## Workarounds

1. **Set 'enable.auto.commit=false' and manually commit offsets only after ensuring the consumer is in a stable state (e.g., after a successful poll that does not trigger rebalance). Add a retry loop with exponential backoff for commit calls.** (85% success)
   ```
   Set 'enable.auto.commit=false' and manually commit offsets only after ensuring the consumer is in a stable state (e.g., after a successful poll that does not trigger rebalance). Add a retry loop with exponential backoff for commit calls.
   ```
2. **Upgrade the Kafka client library to version 3.7.0 or later, which includes a fix for coordinator epoch synchronization in offset commits.** (95% success)
   ```
   Upgrade the Kafka client library to version 3.7.0 or later, which includes a fix for coordinator epoch synchronization in offset commits.
   ```

## Dead Ends

- **** — A restart triggers another rebalance, which may re-introduce the synchronization conflict, especially if the coordinator state is stale. (65% fail)
- **** — This does not prevent the epoch change that causes the conflict; it only delays rebalance detection, possibly masking the underlying issue. (50% fail)