Yeah I am using ack = 0, so that makes sense. I'll need to rethink that, it would seem. It would be nice, wouldn't it, in this case, for the broker to realize this and just forward the messages to the correct leader. Would that be possible?
Also, it would be nice to have a second option to the controlled shutdown (e.g. controlled.shutdown.quiescence.ms), to allow the broker to wait after the controlled shutdown, a prescribed amount of time before actually shutting down the server. Then, I could set this value to something a little greater than the producer's 'topic.metadata.refresh.interval.ms'. This would help with hitless rolling restarts too. Currently, every producer gets a very loud "Connection Reset" with a tall stack trace each time I restart a broker. Would be nicer to have the producers still be able to produce until the metadata refresh interval expires, then get the word that the leader has moved due to the controlled shutdown, and then start producing to the new leader, all before the shutting down server actually shuts down. Does that seem feasible? Jason On Sun, Jun 23, 2013 at 8:23 PM, Jun Rao <jun...@gmail.com> wrote: > Jason, > > Are you using ack = 0 in the producer? This mode doesn't work well with > controlled shutdown (this is explained in FAQ i*n > https://cwiki.apache.org/confluence/display/KAFKA/Replication+tools#)* > * > * > Thanks, > > Jun > > > On Sun, Jun 23, 2013 at 1:45 AM, Jason Rosenberg <j...@squareup.com> wrote: > > > I'm working on trying on having seamless rolling restarts for my kafka > > servers, running 0.8. I have it so that each server will be restarted > > sequentially. Each server takes itself out of the load balancer (e.g. > sets > > a status that the lb will recognize, and then waits more than long enough > > for the lb to stop sending meta-data requests to that server). Then I > > initiate the shutdown (with controlled.shutdown.enable=true). This seems > > to work well, however, I occasionally see warnings like this in the log > > from the server, after restart: > > > > 2013-06-23 08:28:46,770 WARN [kafka-request-handler-2] server.KafkaApis > - > > [KafkaApi-508818741] Produce request with correlation id 7136261 from > > client on partition [mytopic,0] failed due to Leader not local for > > partition [mytopic,0] on broker 508818741 > > > > This WARN seems to persistently repeat, until the producer client > initiates > > a new meta-data request (e.g. every 10 minutes, by default). However, > the > > producer doesn't log any errors/exceptions when the server is logging > this > > WARN. > > > > What's happening here? Is the message silently being forwarded on to the > > correct leader for the partition? Is the message dropped? Are these > WARNS > > particularly useful? > > > > Thanks, > > > > Jason > > >
