[KAFKA-4436] Provide builder pattern for StreamsConfig

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: streams
• Labels: needs-kip
• Assignee: Unassigned
• Reporter: Matthias J. Sax
• Created: 23/Nov/16 22:32
• Updated: 19/May/22 18:03

Description

Currently, StreamsConfig parameters must be set "manually" as key value pairs. This has multiple disadvantages from a user point of view:

• mandatory arguments could be missing
• data types might be wrong
• producer/consumer config parameters could conflict as they might have the same name (user needs to know to prefix them to avoid conflict)

Those problems have different impact: either a runtime exception is thrown if the problem is detected (e.g. missing parameter or wrong type) or the application is just not configured correctly (producer/consumer has wrong config).

A builder pattern would avoid those problems by forcing the user in the first place to specify thing correctly (otherwise, it won't compile). For example something like this:

StreamsConfig config = StreamsConfig.builder()
    .setApplicationId(String appId)
    .addBootstrapServer(String host, int port)
    .addBootstrapServer(String host, int port)
    .addZookeeper(String host, int port)
    .addZookeeper(String host, int port)
    .setStateDirectory(File path)
    .setConsumerConfig(
        ConsumerConfig.builder()
            .setAutoOffsetReset(...)
            .build()
    )
    .build();

Issue Links

• is duplicated by: KAFKA-13913 Provide builders for KafkaProducer/KafkaConsumer and KafkaStreams
• links to: GitHub Pull Request #5722