[
https://issues.apache.org/jira/browse/FLINK-25893?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17486189#comment-17486189
]
Xintong Song commented on FLINK-25893:
--------------------------------------
Hi [~trohrmann],
For problem 2, I think it is indeed a problem. {{ResourceManagerServiceImpl}}
should not only check whether there is a leading {{ResourceManager}}, but also
make sure the leading {{ResourceManager}} is fully started, before calling the
{{ResourceManagerGateway#deregisterApplication}}.
For problem 1, I think it's kind of expected. When there's no leading
{{ResourceManager}}, the {{ResourceManagerServiceImpl}} can respond to a
`deregisterApplication` call by either ignoring the call or report an
exception. When there's a leading {{ResourceManager}} in another process, it is
desired that the non-leading process ignores the `deregisterApplication` call.
On the other hand, if there is no leading {{ResourceManager}} in any process of
the cluster, it would be desired that the failure of `deregisterApplication` is
reported. Since {{ResourceManagerServiceImpl}} cannot know whether there's a
leading {{ResourceManager}} in another process, I think a false alarm in the
non-leading process when there is another leading process is probably better
than failing the `deregisterApplication` silently when there's no leading
process, as in the latter case Kubernetes / Yarn may unexpectedly bring the
master process up again.
> ResourceManagerServiceImpl's lifecycle can lead to exceptions
> -------------------------------------------------------------
>
> Key: FLINK-25893
> URL: https://issues.apache.org/jira/browse/FLINK-25893
> Project: Flink
> Issue Type: Bug
> Components: Runtime / Coordination
> Affects Versions: 1.15.0, 1.14.3
> Reporter: Till Rohrmann
> Priority: Critical
> Labels: pull-request-available
>
> The {{ResourceManagerServiceImpl}} lifecycle can lead to exceptions when
> calling {{ResourceManagerServiceImpl.deregisterApplication}}. The problem
> arises when the {{DispatcherResourceManagerComponent}} is shutdown before the
> {{ResourceManagerServiceImpl}} gains leadership or while it is starting the
> {{ResourceManager}}.
> One problem is that {{deregisterApplication}} returns an exceptionally
> completed future if there is no leading {{ResourceManager}}.
> Another problem is that if there is a leading {{ResourceManager}}, then it
> can still be the case that it has not been started yet. If this is the case,
> then
> [ResourceManagerGateway.deregisterApplication|https://github.com/apache/flink/blob/master/flink-runtime/src/main/java/org/apache/flink/runtime/resourcemanager/ResourceManagerServiceImpl.java#L143]
> will be discarded. The reason for this behaviour is that we create a
> {{ResourceManager}} in one {{Runnable}} and only start it in another. Due to
> this there can be the {{deregisterApplication}} call that gets the {{lock}}
> in between.
> I'd suggest to correct the lifecycle and contract of the
> {{ResourceManagerServiceImpl.deregisterApplication}}.
> Please note that due to this problem, the error reporting of this method has
> been suppressed. See FLINK-25885 for more details.
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
