KAFKA-6541: Fixed a StackOverflow bug in kafka-coordinator-heartbeat-thread

[anhldbk]

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• The bug is caused by infinite recursive calls to ConsumerNetworkClient.disconnect()

• In class org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient, I introduced a boolean field named disconnecting to prevent such calls happen

    public void disconnect(Node node) {
        synchronized (this) {
            if(disconnecting){
                return;
            }
            disconnecting=true;
            failUnsentRequests(node, DisconnectException.INSTANCE);            

            client.disconnect(node.idString());
        }

        // We need to poll to ensure callbacks from in-flight requests on the disconnected socket are fired
        pollNoWakeup();
    }

Summary of testing strategy (including rationale)
for the feature or bug fix. Unit and/or integration
tests are expected for any behaviour change and
system tests should be considered for larger changes.

No test to implement (I think this is a trivial fix)

Committer Checklist (excluded from commit message)

• Verify design and implementation
• Verify test coverage and CI build status
• Verify documentation (including upgrade notes)

[hachikuji]

This should already be fixed. I left a comment on the JIRA.

[hachikuji]

Closing this since it was already fixed. Please reopen the JIRA if you believe the issue has not been addressed.