There is a very weird flow happening in the following case
I have 6 consumer processes running connected to a cluster of 3 brokers. 3 of the consumers (set A) are subscribed to a particular set of topics (topics C) and the other 3 consumers (set B) are subscribed to another set of topics (topics D). All the consumers belong to the same consumer group. All the topics have a replication factor of 3 and are divided into 24 partitions. Each consumer is automatically assigned to 8 partitions of the topic set it is supposed to consume. I have set the assignment pattern to round robin.
If I kill a consumer from set A, topics C are repartitioned successfully in the remaining consumers from set A. Each consumer in set A is now subscribed to 12 partitions from topics C.
But consumers in set B go crazy. All topics and all partitions in D are assigned to any one consumer from B and the rest of the consumers remain idle - All 24 partitions of all topics in set D are assigned to a single process.
I need some idea on how to debug this and what could be the issue?
I believe only the consumers in topic C should be affected. Consumer set B should remain unaffected and definitely not assign all partitions to a single process