Kafka MirrorMaker 2: Deployment, Gotchas, and Disaster Recovery Failback Playbook

A practical guide to deploying Kafka MirrorMaker 2 (MM2) for cluster replication, covering deployment topology, connector configuration, and production gotchas. Key decisions include deploying MM2 alongside the target cluster, choosing between DefaultReplicationPolicy and IdentityReplicationPolicy before going live, and tuning client parameters for high-throughput workloads. Common pitfalls include config drift (sync.topic.configs.enabled is unreliable), and topic recreation on the source causing scrambled offsets that require manual connector reset. The post closes with a detailed failback playbook: validate primary cluster health, establish temporary reverse replication from DR to primary, move consumers before producers, drain replication lag to zero before producer cutover, and always rehearse the procedure in non-production first.