I have a situation where two high level consumers are being created to consume a single topic. There is only one partition for the topic, so I understand that only one Consumer will end up owning the topic and receiving messages. The two consumers are created from two servers in a redundant master - slave configuration, and it is our intention that the servers should start in the same configuration predictably, with all the Consumers active on the master server.
However, we find after both Consumers have been created that sometimes the first Consumer client succeeds in owning the topic and sometimes it is the second. I first thought that the first Consumer client to register with the topic would be retained even if subsequent Consumers also register for the topic, but I see sometimes the second Consumer client succeeds in replacing the first Consumer. The logs show a rebalancing algorithm working after each Consumer is registered. In this case, where there is only one topic-partition, is it possible to predict what Consumer client will own the topic? How is that rebalancing done? Thanks Dennis
