Status

Current state: Under Discussion [One of "Under Discussion", "Accepted", "Rejected"]

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

Motivation

Describe the problems you are trying to solve.

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Thus it is necessary to change the ReassignPartitionsCommand so that it no longer talks to ZooKeeper directly, but via an intermediating broker.

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.

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• --zookeeper will be deprecated, with a warning message
• a new --bootstrap-server option will be added

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.

kafka-reassign-partitions.sh and ReassignPartitionsCommand

The --zookeeper option will be retained and will:

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In all other respects, the public API of ReassignPartitionsCommand will not be changed.

AdminClient

The following methods will be added to AdminClient:

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        public KafkaFuture<Void> all()

  }

Authorization

With broker-mediated reassignment it becomes possible limit the authority to perform reassignment to something finer-grained than "anyone with access to zookeeper".

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    --operation ClusterAction --cluster

Network Protocol: AssignPartitionsRequest and AssignPartitionsResponse

An AssignPartitionsRequest will initiate the process of partition reassignment

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• INVALID_TOPIC_EXCEPTION (17) If the topic doesn't exist
• INVALID_PARTITIONS (37) If the partition doesn't exist
• UNKNOWN_MEMBER_ID (25) If the Replicas in the AssignPartitionsRequest included an unknown broker id

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?

Existing users of the kafka-reassign-partitions.sh will receive a deprecation warning when they use the --zookeeper option. The option will be removed in a future version of Kafka. If this KIP is introduced in version 1.0.0 the removal could happen in 2.0.0.

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.

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