Status

Current state: Under Discussion

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

JIRA: JIRA 6657

Motivation

Kafka Streams allows to pass in different configs for different clients by prefixing the corresponding parameter with `producer.` or `consumer.`.

However, Kafka Streams internally uses multiple consumers, (1) the main consumer (2) the restore consumer and (3) the global consumer

For some use cases, it's required to set different configs for different consumers. Thus, we should add two new prefix for restore and global consumer. 

We might also consider to extend `KafkaClientSupplier` and add a `getGlobalConsumer()` method.

Public Interfaces

// KafkaClientSupplier consumer APIs: 
Consumer<byte[], byte[]> getConsumer(final Map<String, Object> config);
Consumer<byte[], byte[]> getRestoreConsumer(final Map<String, Object> config);
// New API for global consumer:
Consumer<byte[], byte[]> getGlobalConsumer(final Map<String, Object> config); 

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?

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.