Are you sure the topic itself has indeed 1 partition? If so the only partition should be matched to either one till some error/rebalance occurs, does this indeed happen (a lot)?
On Wed, Jul 13, 2016 at 7:19 AM BYEONG-GI KIM <bg...@bluedigm.com> wrote: > Hello. > > I'm not sure whether it's a bug or not, but here is a something wrong; > > I set 2 consumer apps that have same consumer group id, and partition has > been set to 1 on my Kafka Broker. > > In theory, the messages on the Kafka Broker must be consumed either one, > which means it must not be consumed at both of them. But the messages were > sometimes consumed to both of them. > > I found the definition of the partition at the Kafka Website: > *"Kafka only provides a total order over messages within a partition, not > between different partitions in a topic. Per-partition ordering combined > with the ability to partition data by key is sufficient for most > applications. However, if you require a total order over messages this can > be achieved with a topic that has only one partition, though this will mean > only one consumer process per consumer group."* > > What's wrong with my setting? > > Regards > > KIM >
