[KAFKA-3191] Improve offset committing JavaDoc in KafkaConsumer

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.9.0.0
• Fix Version/s: 0.9.0.1, 0.10.0.0
• Component/s: consumer
• Labels: documentation
• Assignee: Adam Kunicki
• Reporter: Adam Kunicki
• Reviewer: Gwen Shapira
• Created: 02/Feb/16 06:45
• Updated: 09/Feb/16 00:57
• Resolved: 09/Feb/16 00:57

Description

http://www.confluent.io/blog/tutorial-getting-started-with-the-new-apache-kafka-0.9-consumer-client includes some great examples of how to manage offset commits in Kafka 0.9.

It is currently unclear from the JavaDoc that the following is expected:

consumer.commitSync(Collections.singletonMap(record.partition(), new
OffsetAndMetadata(record.offset() + 1)));

The committed offset should always be the offset of the next message that
your application will read.

This information should be incorporated into the existing JavaDoc to make it clearer.