This error means that a partition has no leader broker available to serve reads or writes.
Root Causes
- Broker hosting the partition is down.
- ISR (In-Sync Replica) list is empty.
- Topic was just created and metadata hasn’t propagated.
- Zookeeper or controller is unhealthy.
🛠️ Fixes
- Restart affected broker.
- Use:
kafka-topics.sh --describe --topic <topic> --bootstrap-server <broker>
- Force preferred leader election:
kafka-preferred-replica-election.sh
- Check controller logs and ZooKeeper connectivity.