What causes LeaderNotAvailableException?

Partition leader election in progress after a broker restart, crash, or controlled shutdown Preferred leader election running via kafka-preferred-replica-election.sh or auto.leader.rebalance.enable triggered a momentary gap New topic just created; partition leaders not yet elected (brief window during topic creation)

How do I fix LeaderNotAvailableException?

This error is transient and retriable — ensure client 'retries' is set high enough (>=3) and 'retry.backoff.ms' is at least 100ms to survive election windows Monitor unclean leader elections with JMX metric 'UncleanLeaderElectionsPerSec'; if non-zero, investigate broker stability and ensure 'unclean.leader.election.enable=false' If persistent after broker restart, check 'kafka-topics.sh --describe' for partitions showing 'Leader: none' and manually trigger preferred replica election

Is LeaderNotAvailableException retriable?

Yes — LeaderNotAvailableException is a subclass of RetriableException, so Kafka clients can safely retry; it usually clears after a short delay.

Kafka Exception `LeaderNotAvailableException`

org.apache.kafka.common.errors.LeaderNotAvailableException

Retriable Broker

There is no currently available leader for the given partition (either because a leadership election is in progress or because all replicas are down).

Common Causes

Partition leader election in progress after a broker restart, crash, or controlled shutdown
Preferred leader election running via kafka-preferred-replica-election.sh or auto.leader.rebalance.enable triggered a momentary gap
New topic just created; partition leaders not yet elected (brief window during topic creation)

Solutions

This error is transient and retriable — ensure client 'retries' is set high enough (>=3) and 'retry.backoff.ms' is at least 100ms to survive election windows
Monitor unclean leader elections with JMX metric 'UncleanLeaderElectionsPerSec'; if non-zero, investigate broker stability and ensure 'unclean.leader.election.enable=false'
If persistent after broker restart, check 'kafka-topics.sh --describe' for partitions showing 'Leader: none' and manually trigger preferred replica election

Example Stack Trace

org.apache.kafka.common.errors.LeaderNotAvailableException: There is no leader for this topic-partition as we are in the middle of a leadership election.

Diagnostic Commands

# Check for partitions without a leader
kafka-topics.sh --describe --topic <topic> --bootstrap-server localhost:9092 | grep 'Leader: none'

# Check for under-replicated partitions
kafka-topics.sh --describe --bootstrap-server localhost:9092 --under-replicated-partitions

Protocol error: LEADER_NOT_AVAILABLE (code 5)

Hitting LeaderNotAvailableException in production? Conduktor Console gives you real-time visibility into clients, consumer groups, and broker health. Browse every Kafka exception or protocol error code.

Kafka Exception LeaderNotAvailableException

Common Causes

Solutions

Example Stack Trace

Diagnostic Commands

Related

Kafka Exception `LeaderNotAvailableException`