Hi, Kamesh, does one of worker's logs look like in https://issues.apache.org/jira/browse/KAFKA-7941?focusedCommentId=16899851&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-16899851 ? I.e.
INFO [Worker clientId=connect-1, groupId=connect] Was selected to perform assignments, but do not have latest config found in sync request. Returning an empty configuration to trigger re-sync. (org.apache.kafka.connect.runtime.distributed.WorkerCoordinator:208) INFO [GroupCoordinator 3]: Assignment received from leader for group connect for generation 436 (kafka.coordinator.group.GroupCoordinator) INFO [Worker clientId=connect-1, groupId=connect] Successfully joined group with generation 436 (org.apache.kafka.clients.consumer.internals.AbstractCoordinator:455) INFO Joined group and got assignment: Assignment{error=1, leader='connect-1-caf0b504-cb29-4456-a28d-3172cdf67d73', leaderUrl='http://<url>/', offset=1, connectorIds=[], taskIds=[]} (org.apache.kafka.connect.runtime.distributed.DistributedHerder:1216) INFO [Worker clientId=connect-1, groupId=connect] (Re-)joining group (org.apache.kafka.clients.consumer.internals.AbstractCoordinator:491) INFO [GroupCoordinator 3]: Preparing to rebalance group connect in state PreparingRebalance with old generation 436 (__consumer_offsets-30) (reason: Updating metadata for member connect-1-caf0b504-cb29-4456-a28d-3172cdf67d73) (kafka.coordinator.group.GroupCoordinator) INFO [GroupCoordinator 3]: Stabilized group connect generation 437 (__consumer_offsets-30) (kafka.coordinator.group.GroupCoordinator) If so, then it might be the cause. In my experiments, only restarting of workers helps here. The fix might be available soon https://github.com/apache/kafka/pull/6283 Best, Ivan On Sat, 3 Aug 2019 at 19:36, Boyang Chen <reluctanthero...@gmail.com> wrote: > Hey Kamesh, > > thank you for the question. Could you also check the broker side log to see > if the group is forming generations properly? Information we have for now > is a bit hard to tell what's going on. Also since you have upgraded to 2.3, > during incremental rebalancing you will experience 2 rebalance in a row but > won't revoke/assign tasks unless necessary, could you verify that for old > connectors their partitions are not getting revoked during the first > rebalance? > > Boyang > > > > On Sat, Aug 3, 2019 at 1:40 AM Kamesh <kam.iit...@gmail.com> wrote: > > > Hi, > > I am using Kafka connect cluster for writing data to S3. I have > observed, > > whenever I add a new connector or update the config of an existing > > connector, I think group balancing is happening and it is affecting all > the > > existing connectors. Rebalancing is happening for all of the existing > > connectors also. All of my log files are filled with the following log > > messages > > > > *[2019-08-03 08:28:28,668] INFO [Consumer > clientId=connector-consumer-xxx, > > groupId=connect-xxx] (Re-)joining group > > (org.apache.kafka.clients.consumer.internals.AbstractCoordinator:505)* > > > > This rebalancing is taking a very long time, and sometimes not evening > > completing. Any pointers on this? > > > > I am using Kafka connect *2.3.0, *and this version supports incremental > > rebalancing and it should not affect existing connectors. Am I > > missing something? > > > > I have already tuned *session.timeout.ms <http://session.timeout.ms>* > > and *max.poll.interval.ms > > <http://max.poll.interval.ms>* configs and increased their values as > > suggested in the community. > > > > > > Thanks & Regards > > Kamesh. > > >