Kafka Exception MemberIdRequiredException
org.apache.kafka.common.errors.MemberIdRequiredException
Non-retriable
Consumer
MemberIdRequiredException is a Kafka exception (org.apache.kafka.common.errors.MemberIdRequiredException).
Common Causes
- Dynamic group member joined with an empty member.id and the coordinator replied with MEMBER_ID_REQUIRED as part of the normal two-step JoinGroup flow
- Custom or very old client does not resend JoinGroup with the member ID returned by the coordinator
- Application code recreates consumer state during rebalance, so it keeps trying to join without the assigned member.id
Solutions
- For standard Kafka clients, treat this as internal protocol flow: the client should automatically resend JoinGroup with the member ID returned in the response
- If using a custom consumer, implement the KIP-394 protocol: on receiving this error, extract the `memberId` from the response and include it in the subsequent `JoinGroup` request
- If the same consumer loops on MEMBER_ID_REQUIRED instead of progressing, upgrade the client library or stop recreating the consumer during rebalance
Example Stack Trace
org.apache.kafka.common.errors.MemberIdRequiredException: The group member needs to have a valid member id before actually entering a consumer group.Diagnostic Commands
# Look for rebalance events in logs
grep 'MEMBER_ID_REQUIRED\|MemberIdRequired\|JoinGroup' /path/to/kafka/logs/server.log | tail -20
# Show consumer group member assignments
kafka-consumer-groups.sh --bootstrap-server localhost:9092 --describe --group <groupId> | grep -E 'CONSUMER-ID|HOST'Related
Protocol error: MEMBER_ID_REQUIRED (code 79)
Related Consumer exceptions: CommitFailedException · CoordinatorLoadInProgressException · CoordinatorNotAvailableException · FencedInstanceIdException · FencedMemberEpochException · GroupMaxSizeReachedException · IllegalGenerationException · InvalidGroupIdException
Hitting
MemberIdRequiredException in production? Conduktor Console gives you real-time visibility into clients, consumer groups, and broker health. Browse every Kafka exception or protocol error code.