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

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

Describe the problems you are trying to solve.

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

Motivation

At present, it is impossible to perceive the Kafka version that the broker is running from the perspective of metrics. If multiple Kafka versions are deployed in a cluster due to various reasons, it is difficult for us to intuitively understand the version distribution.

So, I want to add a kafka version metric indicating the version of the current running kafka server, it can help us to perceive the mixed distribution of multiple versions, and to perceive the progress of version upgrade in the cluster in real time.

Public Interfaces

• add a kafka version metric for per broker: kafka.server:type=KafkaServer/BrokerServer,name=KafkaVersion
  • description: A gauge metric, the value is the current running server version name.
  • no tags.

Proposed Changes

When instantiating kafkaServer/BrokerServer, register `KafkaVersion` gauge metric, whose value is obtained by `VersionInfo.getVersion`. And remove all related metrics when kafkaServer/BrokerServer shutdownDescribe 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

...

The new metric added to this kip will not have any impact on the existing behavior.

Test Plan

Rejected Alternatives