Group Replication Write Conflicts
warningGroup Replication transactions failing certification due to write conflicts. In multi-primary mode, concurrent writes to same rows on different nodes cause certification failures and transaction rollbacks, reducing effective throughput.
mysql.replication.group.conflicts_detected rate > 5/sec, with mysql.replication.group.transactions_rollback > 0 and increasing
Query performance_schema.replication_group_member_stats for per-member conflict rates. In multi-primary Group Replication, conflicts are expected but high rates indicate poor workload distribution. Consider: 1) Route writes to different primaries by key range or database to reduce overlap, 2) Switch to single-primary mode if multi-primary not required, 3) Review transaction isolation level - REPEATABLE-READ has stricter conflict detection than READ-COMMITTED. Monitor mysql.replication.group.transactions_proposed vs rollback ratio. Use application-level write routing to minimize cross-node conflicts.