[ 
https://issues.apache.org/jira/browse/KAFKA-17116?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

TengYao Chi updated KAFKA-17116:
--------------------------------
    Labels: kip kip-848-client-support  (was: kip-848-client-support needs-kip)

> New consumer may not send effective leave group if member ID received after 
> close 
> ----------------------------------------------------------------------------------
>
>                 Key: KAFKA-17116
>                 URL: https://issues.apache.org/jira/browse/KAFKA-17116
>             Project: Kafka
>          Issue Type: Bug
>          Components: clients, consumer
>    Affects Versions: 3.8.0
>            Reporter: Lianet Magrans
>            Assignee: TengYao Chi
>            Priority: Major
>              Labels: kip, kip-848-client-support
>             Fix For: 4.0.0
>
>
> If the new consumer is closed after sending a HB to join, but before 
> receiving the response to it, it will send a leave group request but without 
> member ID (will simply fail with UNKNOWN_MEMBER_ID). This will make that the 
> broker will have a registered new member, for which it will never receive a 
> leave request for it.
>  # consumer.subscribe -> sends HB to join, transitions to JOINING
>  # consumer.close -> will transition to LEAVING and send HB with epoch -1 
> (without waiting for in-flight requests)
>  # consumer receives response to initial HB, containing the assigned member 
> ID. It will simply ignore it because it's not in the group anymore 
> (UNSUBSCRIBED)
> Note that the expectation, with the current logic, and main downsides of this 
> are:
>  # If the case was that the member received partitions on the first HB, those 
> partitions won't be re-assigned (broker waiting for the closed consumer to 
> reconcile them), until the rebalance timeout expires. 
>  # Even if no partitions were assigned to it, the member will remain in the 
> group from the broker point of view (but not from the client POV). The member 
> will be eventually kicked out for not sending HBs, but only when it's session 
> timeout expires.



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

Reply via email to