Jun, can you explain this a little better? I thought when using Consumer Groups that on startup Kafka connects to ZooKeeper and finds the last read offset for every partition in the topic being requested for the group. That is then the starting point for the consumer threads.
If a second process starts while the first one is running with the same Consumer Group, won't the second one read the last offsets consumed by the already running process and start processing from there? Then as the first process syncs consumed offsets, won't the 2nd process's next update overwrite them? Thanks, Chris On Mon, Apr 29, 2013 at 11:03 AM, Jun Rao <jun...@gmail.com> wrote: > Chris, > > Thanks for the writeup. Looks great overall. A couple of comments. > > 1. At the beginning, it sounds like that one can't run multiple processes > of consumers in the same group. This is actually not true. We can create > multiple instances of consumers for the same group in the same JVM or > different JVMs. The consumers will auto-balance among themselves. > > 2. We have changed the name of some config properties. > auto.commit.interval.ms is correct. However, zk.connect, > zk.session.timeout.ms and zk.sync.time.ms are changed to > zookeeper.connect, > zookeeper.session.timeout.ms, and zookeeper.sync.time.ms, respectively. > > I will add a link to your wiki in our website. > > Thanks again. > > Jun > > > On Mon, Apr 29, 2013 at 5:54 AM, Chris Curtin <curtin.ch...@gmail.com > >wrote: > > > Hi Jun, > > > > I finished and published it this morning: > > > > https://cwiki.apache.org/confluence/display/KAFKA/Consumer+Group+Example > > > > One question: when documenting the ConsumerConfig parameters I couldn't > > find a description for the 'auto.commit.interval.ms' setting. I found > one > > for 'autocommit.interval.ms' (no '.' between auto and commit) in the > > Google > > Cache only. Which spelling is it? Also is my description of it correct? > > > > I'll take a look at custom encoders later this week. Today and Tuesday > are > > going to be pretty busy. > > > > Please let me know if there are changes needed to the High Level Consumer > > page. > > > > Thanks, > > > > Chris > > > > > > On Mon, Apr 29, 2013 at 12:50 AM, Jun Rao <jun...@gmail.com> wrote: > > > > > Chris, > > > > > > Any update of the high level consumer example? > > > > > > Also, in the Producer example, it would be useful to describe how to > > write > > > a customized encoder. One subtle thing is that the encoder needs a > > > constructor that takes a a single VerifiableProperties argument ( > > > https://issues.apache.org/jira/browse/KAFKA-869). > > > > > > Thanks, > > > > > > Jun > > > > > > > > > > > > > > >
