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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]

(v1.2.0)

Discussion thread: No discussion thread: Vote for KIP-245: Use Properties instead of StreamsConfig in KafkaStreams constructor

JIRA: hereJIRA: 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

Currently, KafkaStreams constructor has overloads that take either Properties or StreamsConfig a parameters.

Because StreamsConfig is immutable and is created from a Properties object itself, the constructors accepting StreamsConfig are not useful and adds only boiler plate code. Thus, we should deprecate those constructors in order to remove them eventually.

Public Interfaces

// Old API (using StreamsConfig)
public KafkaStreams(final Topology, final StreamsConfig config) 
public KafkaStreams(final Topology, final StreamsConfig config, final KafkaClientSupplier clientSupplier) 
public KafkaStreams(final Topology, final StreamsConfig config, final Time time) 


// New API (using Properties)
public KafkaStreams(final Topology, final Properties props) 
public KafkaStreams(final Topology, final Properties props, final KafkaClientSupplier clientSupplier) 
public KafkaStreams(final Topology, final Properties props, final Time time) 
public KafkaStreams(final Topology, final Properties props, final KafkaClientSupplier clientSupplier, final Time time) 

Proposed Changes

We suggest to deprecate all the constructors using StreamsConfig, and use java.util.Properties insteadDescribe 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

• We are not removing any existing API, so this change should be backward compatible. All new APIs are straightforward which don't require excessive comments.

Rejected Alternatives

Not applicableIf 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.