This page is meant as a template for writing a KIP. To create a KIP choose Tools->Copy on this page and modify with your content and replace the heading with the next KIP number and a description of your issue. Replace anything in italics with your own description.

Status

Current state: Draft

Discussion thread: here [Change the link from the KIP proposal email archive to your own email thread]

JIRA: here [Change the link from KAFKA-1 to your own ticket]

Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

Motivation

One of MM2 main feature is syncing consumer group offset between clusters. This feature relays on two separate connectors
- `MirrorSourceConnector`: this connector stores the translation of new recored's offset on target cluster in `offset_syncs` internal topic after mirroring the record. This translation is done at `commit` method since 3.5 where `commit()` API stores the offsets in the source system, up to the offsets that have been returned by `poll()`. The implementation of this API should block until the commit is complete. See [KAFKA-14610](https://issues.apache.org/jira/browse/KAFKA-14610) for more details.
- `MirrorCheckpointConnector`: this connector uses the new record offsets from `offset_syncs` and update `checkpoints` and `__consumer_offsets` topics. This can be controlled by `emit.checkpoints` and `sync.group.offsets`

For use-cases where customers only run MM2 for replicating between clusters without need for moving the consumer group offsets by running only MirrorSourceConnector still left with part#1 of this feature which add cost to the progress of their replication.

This KIP propose that we add a new config for `MirrorSourceConnector` to control enabling the translation of offsets between clusters for replicated topics.

Public Interfaces

Briefly list any new interfaces that will be introduced as part of this proposal or any existing interfaces that will be removed or changed. The purpose of this section is to concisely call out the public contract that will come along with this feature.

A public interface is any change to the following:

• Binary log format

• The network protocol and api behavior

• Any class in the public packages under clientsConfiguration, especially client configuration

  • org/apache/kafka/common/serialization

  • org/apache/kafka/common

  • org/apache/kafka/common/errors

  • org/apache/kafka/clients/producer

  • org/apache/kafka/clients/consumer (eventually, once stable)

• Monitoring

• Command line tools and arguments

• Anything else that will likely break existing users in some way when they upgrade

Proposed Changes

Describe the new thing you want to do in appropriate detail. This may be fairly extensive and have large subsections of its own. Or it may be a few sentences. Use judgement based on the scope of the change.

Compatibility, Deprecation, and Migration Plan

• What impact (if any) will there be on existing users?
• If we are changing behavior how will we phase out the older behavior?
• If we need special migration tools, describe them here.
• When will we remove the existing behavior?

Test Plan

Describe in few sentences how the KIP will be tested. We are mostly interested in system tests (since unit-tests are specific to implementation details). How will we know that the implementation works as expected? How will we know nothing broke?

Rejected Alternatives

If there are alternative ways of accomplishing the same thing, what were they? The purpose of this section is to motivate why the design is the way it is and not some other way.