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Status

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

Discussion thread: hereskipped

JIRA: here

Released:  <Kafka Version>targeting 4.2.0

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

Motivation

Kafka Streams tries to protect data written into the local state directory, by setting write permission only for the user/owner of the application (cf

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

We propose to add a new config, allow.os.group.write.access with a default value of "false". A corresponding entry will be added to StreamsConfig.java:

public class StreamsConfig {
  // newly added
   public static final String ALLOW_OS_GROUP_WRITE_ACCESS_CONFIG = "allow.os.group.write.access";
}

Proposed Changes

On startup, when Kafka Streams verifies the permission for the state directory, it will revoke group write access by default, but if allow.os.group.write.access is set to "true", it will grant group write accessDescribe 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?

For Kafka Streams deprecation, please add a corresponding sub-task to

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?

Documentation Plan

What will the impact be on the documentation? List any affected areas/files. 

Rejected Alternatives

We are adding a new config, and do not change the default behavior, so there is no backward compatibility concerns. Of course, if user enable this new feature and downgrade to an older version of Kafka Streams, the granted write access would get revoked again.

Test Plan

Unit testing should be sufficient.

Documentation Plan

The new config will be added to the docs.

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.