[KAFKA-345] Add a listener to ZookeeperConsumerConnector to get notified on rebalance events

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.7, 0.8.0
• Component/s: core
• Assignee: Jiangjie Qin
• Reporter: Peter Romianowski
• Created: 18/May/12 14:34
• Updated: 08/Apr/15 00:30
• Resolved: 08/Apr/15 00:30

Description

A sample use-case

In our scenario we partition events by userid and then apply these to some kind of state machine, that modifies the actual state of a user. So events trigger state transitions. In order to avoid the need of loading user's state upon each event processed, we cache that. But if a user's partition is moved to another consumer and then back to the previous consumer we have stale caches and hell breaks loose. I guess the same kind of problem occurs in other scenarios like counting numbers by user, too.

Issue Links

• is depended upon by: KAFKA-346 Don't call commitOffsets() during rebalance