Hi Zaiming, It rules out the most likely cause of rebalance, but not the only one. Rebalances can also be caused by a topic metadata change or a coordinator change. Can you post some logs from the consumer around the time that the unexpected rebalance occurred?
-Jason On Fri, Mar 25, 2016 at 12:09 AM, Zaiming Shi <zmst...@gmail.com> wrote: > Hi Jason > > thanks for the reply! > > Forgot to mention that in we tried to test the simplest scenario in which > there was only one member in the group. I think that should rule out group > rebalancing right? > > On Thursday, March 24, 2016, Jason Gustafson <ja...@confluent.io> wrote: > > > HI Zaiming, > > > > I think the problem is not that commit requests aren't considered as > > effective as heartbeats (they are), but that you can't rejoin the group > > using only commits/heartbeats. Every time the group rebalances, all > members > > must rejoin the group by sending a JoinGroup request. Once a rebalance > has > > begun (e.g. because a new consumer has been started), then each member > must > > send the JoinGroup before expiration of the session timeout. If not, then > > they will be kicked out of the group even if they are still sending > > heartbeats. Does that make sense? > > > > -Jason > > > > > > > > On Wed, Mar 23, 2016 at 10:03 AM, Zaiming Shi <zmst...@gmail.com > > <javascript:;>> wrote: > > > > > Hi there! > > > > > > We have noticed that when committing requests are sent intensively, we > > > receive IllegalGenerationId. > > > Here is the settings we had problem with: session-timeout: 30 sec, > > > heartbeat-rate: 3 sec. > > > Problem resolved by increasing the session timeout to 180 sec. > > > > > > So I suppose, due to whatever reason (either the client didn't send > > > heartbeat, or the broker didn't process the heartbeats in time), the > > > session was considered dead in group coordinator. > > > > > > My question is: why commit requests can't be taken as an indicator of > > > member being alive? hence not to kill the session. > > > > > > Regards > > > -Zaiming > > > > > >
