[
https://issues.apache.org/jira/browse/KAFKA-14000?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17619780#comment-17619780
]
Greg Harris commented on KAFKA-14000:
-------------------------------------
This looks like similar symptoms as
https://issues.apache.org/jira/browse/KAFKA-12525 except that the task status
tombstones are racing the task statuses.
I like the "sort by generation" strategy of only accepting the latest
generation for each task. However, I don't expect that this will address the
potential tombstone racing issues, as tombstones will not have a generation ID
to compare with.
> Kafka-connect standby server shows empty tasks list
> ---------------------------------------------------
>
> Key: KAFKA-14000
> URL: https://issues.apache.org/jira/browse/KAFKA-14000
> Project: Kafka
> Issue Type: Bug
> Components: KafkaConnect
> Affects Versions: 2.6.0
> Reporter: Xinyu Zou
> Assignee: Sagar Rao
> Priority: Major
> Attachments: kafka-connect-trace.log
>
>
> I'm using Kafka-connect distributed mode. There're two servers. One active
> and one standby. The standby server sometimes shows empty tasks list in
> status rest API response.
> curl host:8443/connectors/name1/status
> {code:java}
> {
> "connector": {
> "state": "RUNNING",
> "worker_id": "1.2.3.4:10443"
> },
> "name": "name1",
> "tasks": [],
> "type": "source"
> } {code}
> I enabled TRACE log and checked. As required, the connect-status topic is set
> to cleanup.policy=compact. But messages in the topic won't be compacted
> timely. They will be compacted in a specific interval. So usually there're
> more than one messages with same key. E.g. When kafka-connect is launched
> there's no connector running. And then we start a new connector. Then there
> will be two messages in connect-status topic:
> status-task-name1 : state=RUNNING, workerId='10.251.170.166:10443',
> generation=100
> status-task-name1 : _<emtpy>_
> Please check the log file [^kafka-connect-trace.log]. We can see that the
> tasks status was removed finally. But actually the empty status was not the
> newest message in topic connect-status.
>
> When reading status from connect-status topic, it doesn't sort messages by
> generation.
> [https://github.com/apache/kafka/blob/trunk/clients/src/main/java/org/apache/kafka/clients/consumer/ConsumerRecords.java]
> So I think this could be improved. We can either sort the messages after poll
> or compare generation value before we choose correct status message.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
