Affects Version/s: 0.11.0.0
Fix Version/s: 0.11.0.0
1. It would be safer to hold onto the leader lock in Partition while serving an OffsetForLeaderEpoch request.
2. Currently, we update the leader epoch in epochCache after log append in the follower but before log append in the leader. It would be more consistent to always do this after log append. This also avoids issues related to failure in log append.
The code that does grouping can probably be replaced by calling CollectionUtils.groupDataByTopic(). Done: https://github.com/apache/kafka/commit/359a68510801a22630a7af275c9935fb2d4c8dbf
4. The following line in LeaderEpochFileCache is hit several times when LogTest is executed:
This should be an assert (with the tests fixed up)
5. The constructor of LeaderEpochFileCache has the following:
But everywhere else uses a read or write lock. We should use consistent locking.