Kafka Error INCONSISTENT_VOTER_SET
Error code 94 · Non-retriable KRaft
Indicates that the either the sender or recipient of a voter-only request is not one of the expected voters.
Common Causes
- A KRaft controller quorum request was sent to or from a broker that is not in the current voter set defined in the metadata log
- Cluster was reconfigured (voter set change via KIP-853) but some nodes still have stale voter configuration from the old quorum
- A node was added or removed from the KRaft voter set but the metadata propagation did not complete before requests were issued
Solutions
- Verify all KRaft controller nodes agree on the current voter set by checking kafka-metadata-quorum.sh describe on each controller endpoint
- During voter set changes, follow the KRaft reconfiguration protocol exactly — do not skip the AddVoter/RemoveVoter sequence, and wait for quorum confirmation before proceeding
- If a node is incorrectly excluded from or included in the voter set, correct the controller.quorum.voters configuration and restart the affected nodes in the proper sequence
Diagnostic Commands
# Check KRaft metadata quorum status
kafka-metadata-quorum.sh --bootstrap-server localhost:9092 describe --status
# Show KRaft quorum replication details
kafka-metadata-quorum.sh --bootstrap-server localhost:9092 describe --replication | grep -E 'VOTER|OBSERVER|LEADER'Related APIs
This error can be returned by: BeginQuorumEpoch · EndQuorumEpoch · Vote
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