[jira] [Resolved] (KAFKA-18095) Consider allowing member to join without subscription under new consumer protocol

["David Jacot (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/KAFKA-18095?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

David Jacot resolved KAFKA-18095.
---------------------------------
    Resolution: Fixed

> Consider allowing member to join without subscription under new consumer protocol
> ---------------------------------------------------------------------------------
>
>                 Key: KAFKA-18095
>                 URL: https://issues.apache.org/jira/browse/KAFKA-18095
>             Project: Kafka
>          Issue Type: Improvement
>          Components: group-coordinator
>            Reporter: Lianet Magrans
>            Assignee: David Jacot
>            Priority: Minor
>              Labels: kip-848
>             Fix For: 4.0.0
>
>
> With the new consumer group protocol we currently enforce that members must provide subscribed topics or a regex when joining the group. This prevents members to join in cases where it subscribes to a java pattern for which the client-side resolution finds no matching topics.
> If we relax this validation, we would end up with a more consistent behaviour for the regex subscriptions under the new protocol, given that currently, if the regex is resolved on the broker and finds no matching topics, the member is still allowed in the group (with no assignments), but if resolved on the client it doesn't join.
> Also, the consumer could continue to guarantee that it joins after subscribe(Pattern), no matter if there are matching topics or not.
> If we implement this change on the group coordinator, we also need to update the new consumer to actually attempt to join after a call to subscribe(Pattern) if no matching topics found (related jira)



--
This message was sent by Atlassian Jira
(v8.20.10#820010)