kafka mirrormaker testing

[saloni-2404]

Hi team,
While testing kafka mirrormaker, we created topics in the target cluster and tried to run consumer script there. (Having run producer script in source cluster)

While we got 0 messages transfered, in the mirrormaker logs we see:
2021-04-13 13:23:40,858 DEBUG [Consumer clientId=test-group-0, groupId=test-group] Node 1 sent an incremental fetch response for session 635195420 with 0 response partition(s), 6 implied partition(s) (org.apache.kafka.clients.FetchSessionHandler) [mirrormaker-thread-0]
2021-04-13 13:23:40,858 DEBUG [Consumer clientId=test-group-0, groupId=test-group] Added READ_UNCOMMITTED fetch request for partition topic4-4 at position FetchPosition{offset=0, offsetEpoch=Optional.empty, currentLeader=LeaderAndEpoch{leader=35.231.243.194:9094 (id: 1 rack: null), epoch=0}} to node 35.231.243.194:9094 (id: 1 rack: null) (org.apache.kafka.clients.consumer.internals.Fetcher) [mirrormaker-thread-0]
2021-04-13 13:23:40,858 DEBUG [Consumer clientId=test-group-0, groupId=test-group] Added READ_UNCOMMITTED fetch request for partition topic4-1 at position FetchPosition{offset=0, offsetEpoch=Optional.empty, currentLeader=LeaderAndEpoch{leader=35.231.243.194:9094 (id: 1 rack: null), epoch=0}} to node 35.231.243.194:9094 (id: 1 rack: null) (org.apache.kafka.clients.consumer.internals.Fetcher) [mirrormaker-thread-0]
2021-04-13 13:23:40,858 DEBUG [Consumer clientId=test-group-0, groupId=test-group] Added READ_UNCOMMITTED fetch request for partition topic4-7 at position FetchPosition{offset=0, offsetEpoch=Optional.empty, currentLeader=LeaderAndEpoch{leader=35.231.243.194:9094 (id: 1 rack: null), epoch=0}} to node 35.231.243.194:9094 (id: 1 rack: null) (org.apache.kafka.clients.consumer.internals.Fetcher) [mirrormaker-thread-0]
2021-04-13 13:23:40,858 DEBUG [Consumer clientId=test-group-0, groupId=test-group] Added READ_UNCOMMITTED fetch request for partition sampledata-8 at position FetchPosition{offset=0, offsetEpoch=Optional.empty, currentLeader=LeaderAndEpoch{leader=35.231.243.194:9094 (id: 1 rack: null), epoch=0}} to node 35.231.243.194:9094 (id: 1 rack: null) (org.apache.kafka.clients.consumer.internals.Fetcher) [mirrormaker-thread-0]
2021-04-13 13:23:40,858 DEBUG [Consumer clientId=test-group-0, groupId=test-group] Added READ_UNCOMMITTED fetch request for partition sampledata-2 at position FetchPosition{offset=0, offsetEpoch=Optional.empty, currentLeader=LeaderAndEpoch{leader=35.231.243.194:9094 (id: 1 rack: null), epoch=0}} to node 35.231.243.194:9094 (id: 1 rack: null) (org.apache.kafka.clients.consumer.internals.Fetcher) [mirrormaker-thread-0]
2021-04-13 13:23:40,858 DEBUG [Consumer clientId=test-group-0, groupId=test-group] Added READ_UNCOMMITTED fetch request for partition sampledata-5 at position FetchPosition{offset=0, offsetEpoch=Optional.empty, currentLeader=LeaderAndEpoch{leader=35.231.243.194:9094 (id: 1 rack: null), epoch=0}} to node 35.231.243.194:9094 (id: 1 rack: null) (org.apache.kafka.clients.consumer.internals.Fetcher) [mirrormaker-thread-0]
2021-04-13 13:23:40,858 DEBUG [Consumer clientId=test-group-0, groupId=test-group] Built incremental fetch (sessionId=635195420, epoch=2479) for node 1. Added 0 partition(s), altered 0 partition(s), removed 0 partition(s) out of 6 partition(s) (org.apache.kafka.clients.FetchSessionHandler) [mirrormaker-thread-0]
2021-04-13 13:23:40,858 DEBUG [Consumer clientId=test-group-0, groupId=test-group] Sending READ_UNCOMMITTED IncrementalFetchRequest(toSend=(), toForget=(), implied=(topic4-4, topic4-1, topic4-7, sampledata-8, sampledata-2, sampledata-5)) to broker 35.231.243.194:9094 (id: 1 rack: null) (org.apache.kafka.clients.consumer.internals.Fetcher) [mirrormaker-thread-0]

Does this seem fine?

[scholzj]

I don't see anything special.

[saloni-2404]

@scholzj We were unable to see the data transfer, and did not even find anything, any error in the logs.
What could be the reason for data not replicating using MM?
Is there any way we can see in the logs?

[scholzj]

I think you would need to provide a lot more details ... full logs from all components, configurations etc. That maybe shows something more. I'm not a Mirror Maker expert. But the above IMHO doesn't suggest any issue. But it is also just few messages within a single millisecond.