Hi Guozhang, I really appreciate the detailed explanation! Does this mean that the rule “1 partition will be consumed by exactly one consumer in the consumer group” will only be checked and ensured at the consumer side? Also, does the “consumer group registration in Zookeeper” need to be taken care by the consumer group itself? I think made a mistake in “there is no consumer group name included in any kind of request” because the "clientId acts as the logical grouping”. Sorry about that.
Thanks! Churu On Mar 14, 2014, at 5:21 PM, Guozhang Wang <wangg...@gmail.com> wrote: > Hi Churu, > > Brokers are actually not aware of the consumer groups, the consumer groups > is maintained within the consumers (and registered in ZK) to achieve load > balance. After the group has decided who-consume-which-partition, then each > consumer will do their fetching independently and send fetching requests to > the brokers. Brokers on the other hand will just blindly respond to the > fetch requests. > > Hope this helps. > > Guozhang > > > On Fri, Mar 14, 2014 at 4:50 PM, Churu Tang <ct...@rubiconproject.com>wrote: > >> Hi, >> >> "Consumers label themselves with a consumer group name", and consumer >> group name should be global across each Kafka cluster. However, when I >> check the API, there is no "consumer group name" included in any kind of >> request(metadata, produce, fetch, offset). Does the broker know about the >> consumer group name? >> >> Thanks for your time! >> >> Cheers, >> churu > > > > > -- > -- Guozhang