...

For either human or application use case, it would be good to know the version of brokers we are talking to, so that we could make some decisions automatically, such as which version of client we should use.

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

...

, such as the use case we face in KIP-447. Note that we already have a legacy support in the Scala BrokerApiVersionsCommand. This would be serving as a good purpose to amend this API gap.

Public Interfaces

A new command line API to help us find the API version:

public static List<ApiVersion> getApiVersion(String groupId, Node target, GetApiVersionOptions options);

And a separate option class:

public class GetApiVersionOptions extends AbstractOptions<GetApiVersionOptions>;

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?

Rejected Alternatives

Since this is a new API, there should be no compatibility concern.

Rejected Alternatives

N/AIf 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.