[
https://issues.apache.org/jira/browse/KAFKA-6995?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17451907#comment-17451907
]
Jørgen commented on KAFKA-6995:
-------------------------------
Are there any other ways to proactively leave the group when a KS stops
gracefully, except "internal.leave.group.on.close"? We have a lot of stateless
applications where we want to trigger rebalance immediately if an instance is
stopped to reduce downtime?
Calling kafka-consumer#close explicitly sends a leave-group to trigger
rebalance. From kafka definitive guide:
{quote}When closing a consumer cleanly, the consumer will notify the group
coordinator that it is leaving, and the group coordinator will trigger a
rebalance immediately, reducing the gap in processing.
{quote}
This would be very convenient for many of our kafka-streams usecases as well.
The new default in KIP-735 also makes this a bigger problem (45s session
timeout).
> Make config "internal.leave.group.on.close" public
> --------------------------------------------------
>
> Key: KAFKA-6995
> URL: https://issues.apache.org/jira/browse/KAFKA-6995
> Project: Kafka
> Issue Type: Improvement
> Components: consumer, streams
> Reporter: Boyang Chen
> Assignee: Boyang Chen
> Priority: Major
> Labels: needs-kip
>
> We are proposing to make the config "internal.leave.group.on.close" public.
> The reason is that for heavy state application the sticky assignment won't
> work because each stream worker will leave group during rolling restart, and
> there is a possibility that some members are left and rejoined while others
> are still awaiting restart. This would then cause multiple rebalance because
> after the ongoing rebalance is done, we are expecting late members to rejoin
> and move state from `stable` to `prepareBalance`. To solve this problem,
> heavy state application needs to use this config to avoid member list update,
> so that at most one rebalance will be triggered at a proper time when all the
> members are rejoined during rolling restart. This should just be one line
> change.
> Code here:
> * <code>internal.leave.group.on.close</code>
> * Whether or not the consumer should leave the group on close. If set to
> <code>false</code> then a rebalance
> * won't occur until <code>session.timeout.ms</code> expires.
> *
> * <p>
> * Note: this is an internal configuration and could be changed in the future
> in a backward incompatible way
> *
> */
> static final String LEAVE_GROUP_ON_CLOSE_CONFIG =
> "internal.leave.group.on.close";
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
