[
https://issues.apache.org/jira/browse/KAFKA-2350?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14639746#comment-14639746
]
Jiangjie Qin commented on KAFKA-2350:
-------------------------------------
[~guozhang], my understanding is that pause/unpause will also need to do the
call trace, right? Otherwise if user are not using consumer coordinator, what
would pause/unpause do for them? Is that exactly the same as
subscribe/unsubscribe at partition level? Also, we have to do sub/unsub call
trace anyway, otherwise, how can we enforce mutual exclusion of auto/manual
partition assignment mode?
In terms of rebalance issue. Do you mean we can avoid the issue with
pause/unpause?
I see the same issue. Consider the following:
{code}
subscribe(topicA);
// then say assignment() return me topicA-partition1.
poll(); // Say partition has been assigned to other consumer
pause(topicA-partition1); // Should we throw exception?
unpause(topicA-partition1); // Should we throw exception here?
{code}
> Add KafkaConsumer pause capability
> ----------------------------------
>
> Key: KAFKA-2350
> URL: https://issues.apache.org/jira/browse/KAFKA-2350
> Project: Kafka
> Issue Type: Improvement
> Reporter: Jason Gustafson
> Assignee: Jason Gustafson
>
> There are some use cases in stream processing where it is helpful to be able
> to pause consumption of a topic. For example, when joining two topics, you
> may need to delay processing of one topic while you wait for the consumer of
> the other topic to catch up. The new consumer currently doesn't provide a
> nice way to do this. If you skip poll() or if you unsubscribe, then a
> rebalance will be triggered and your partitions will be reassigned.
> One way to achieve this would be to add two new methods to KafkaConsumer:
> {code}
> void pause(String... topics);
> void unpause(String... topics);
> {code}
> When a topic is paused, a call to KafkaConsumer.poll will not initiate any
> new fetches for that topic. After it is unpaused, fetches will begin again.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
