Hello,
I am running logstash 2.2.2 and I recently upgraded kafka input/output 3.x plugin to support consumer offset storage to Kafka 0.9
As a result, I am connecting to brokers as oppose to Zookeepers. But what I have noticed, since this change, the load balancing is broken. As not all consumers are being assigned to topic partitions resulting in kafka lag increase. Before the upgrade i didn't have this issue as zookeepers where handling the loadbalancing