[KAFKA-4693] Consumer subscription change during rebalance causes exception

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: consumer
• Assignee: Unassigned
• Reporter: Jason Gustafson
• Created: 24/Jan/17 21:19
• Updated: 17/Feb/19 19:14

Description

After every rebalance, the consumer validates that the assignment received contains only partitions from topics that were subscribed. If not, then we raise an exception to the user. It is possible for a wakeup or an interrupt to leave the consumer with a rebalance in progress (e.g. with a JoinGroup to the coordinator in-flight). If the user then changes the topic subscription, then this validation upon completion of the rebalance will fail. We should probably detect the subscription change, eat the exception, and request another rebalance.