I am running MirrorMaker 2 (Kafka 2.7), trying to migrate all topics from one cluster to another while preserving through `sync.group.offsets.enabled=true`. My source cluster is running Kafka 0.10, while the target cluster is running 2.6.1.
While I can see data being replicated, the data on the replicated Consumer Group in the target cluster looks wrong. The lag values of the replicated Consumer Group are large negative values, and the LOG-END-OFFSET are mostly 0. I determined this information from kafka-consumer-groups.sh. I checked the kafka_consumer_consumer_fetch_manager_metrics_records_lag JMX metrics in MM2 and the reported lag is zero for all partitions. By using `sync.group.offsets.enabled=true`, I envisioned that MM2 will automatically replicate and sync all Consumer Groups with a meaningful offset in the target cluster. Am I misunderstanding how MM2 is supposed to work? Here is my mm2.properties and the CG details. # mm2.properties ``` clusters = src, dst src.bootstrap.servers = 10.0.0.1:9092 dst.bootstrap.servers = 10.0.0.2:9092 src->dst.enabled = true src->dst.topics = compute.* src->dst.offset.flush.timeout.ms=60000 src->dst.buffer.memory=10000 dst->src.enabled = true dst->src.topics = .* replication.factor=3 src->dst.sync.group.offsets.enabled = true src->dst.emit.checkpoints.enabled = true src->dst.consumer.auto.offset.reset=latest consumer.auto.offset.reset = latest auto.offset.reset = latest replication.policy.class = com.amazonaws.kafka.samples.CustomMM2ReplicationPolicy checkpoints.topic.replication.factor=3 heartbeats.topic.replication.factor=3 offset-syncs.topic.replication.factor=3 offset.storage.replication.factor=3 status.storage.replication.factor=3 config.storage.replication.factor=3 sync.topic.acls.enabled = false sync.group.offsets.enabled = true emit.checkpoints.enabled = true tasks.max = 8 dst.producer.offset.flush.timeout.ms = 60000 dst.offset.flush.timeout.ms = 60000 ``` Consumer Group details ``` GROUP TOPIC PARTITION CURRENT-OFFSET LOG-END-OFFSET LAG CONSUMER-ID HOST CLIENT-ID kafka-group-Compute-Requests Compute-Requests 57 5305947 0 -5305947 - - - kafka-group-Compute-Requests Compute-Requests 20 5164205 0 -5164205 - - - kafka-group-Compute-Requests Compute-Requests 53 4208527 0 -4208527 - - - kafka-group-Compute-Requests Compute-Requests 82 5247928 0 -5247928 - - - kafka-group-Compute-Requests Compute-Requests 65 5574520 0 -5574520 - - - kafka-group-Compute-Requests Compute-Requests 11 5190708 209 -5190499 - - - ``` Thanks ... Alan