This PR replaces https://github.com/apache/kafka/pull/2743 (just raising from Confluent repo)
This PR describes the addition of Partition Level Leader Epochs to messages in Kafka as a mechanism for fixing some known issues in the replication protocol. Full details can be found here:
[KIP-101 Reference](https://cwiki.apache.org/confluence/display/KAFKA/KIP-101+-+Alter+Replication+Protocol+to+use+Leader+Epoch+rather+than+High+Watermark+for+Truncation)
*The key elements are*:
- Epochs are stamped on messages as they enter the leader.
- Epochs are tracked in both leader and follower in a new checkpoint file.
- A new API allows followers to retrieve the leader's latest offset for a particular epoch.
- The logic for truncating the log, when a replica becomes a follower, has been moved from Partition into the ReplicaFetcherThread
- When partitions are added to the ReplicaFetcherThread they are added in an initialising state. Initialising partitions request leader epochs and then truncate their logs appropriately.
This test provides a good overview of the workflow `EpochDrivenReplicationProtocolAcceptanceTest.shouldFollowLeaderEpochBasicWorkflow()`
The corrupted log use case is covered by the test
`EpochDrivenReplicationProtocolAcceptanceTest.offsetsShouldNotGoBackwards()`
Remaining work: There is a do list here: https://docs.google.com/document/d/1edmMo70MfHEZH9x38OQfTWsHr7UGTvg-NOxeFhOeRew/edit?usp=sharing
Author: Ben Stopford <benstopford@gmail.com>
Author: Jun Rao <junrao@gmail.com>
Reviewers: Ismael Juma <ismael@juma.me.uk>, Jun Rao <junrao@gmail.com>
Closes#2808 from benstopford/kip-101-v2
Author: Parth Brahmbhatt <brahmbhatt.parth@gmail.com>
Reviewers: Ismael Juma <ismael@juma.me.uk>, Jun Rao <junrao@gmail.com>
Closes#195 from Parth-Brahmbhatt/KAFKA-2211
Ben Stopford
Parth Brahmbhatt
Raman Gupta
Jay Kreps
Joe Stein
Jun Rao
Swapnil Ghike
Neha Narkhede
Neha Narkhede
Jun Rao
Edward Jay Kreps