Eno Thereska created KAFKA-4875:
-----------------------------------
Summary: Kafka streams topic groups and builder.stream API
Key: KAFKA-4875
URL: https://issues.apache.org/jira/browse/KAFKA-4875
Project: Kafka
Issue Type: Improvement
Components: streams
Affects Versions: 0.10.2.0
Reporter: Eno Thereska
Fix For: 0.11.0.0
One thing that has come up in mailing list is that the notion of topic groups
is unclear. So if you have 2 topics, each with 3 partitions, you'd expect 6
tasks. However, if you do `builder.stream(topic1, topic2)` you actually get
only 3 tasks created. If you do `builder.stream(topic1);
builder.stream(topic2)` you get 6 tasks, i.e., parallelism is increased. So the
same application, calling builder.stream() in two different ways, might see
different performance.
In the Kafka Streams documentations we mention partitions and tasks, but not
topic groups. We also do not document the effects of using builder.stream with
a topic array. We also need to revisit whether the API and its effects are
confusing.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
