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https://issues.apache.org/jira/browse/KAFKA-5242?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16011025#comment-16011025
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Matthias J. Sax commented on KAFKA-5242:
----------------------------------------
Both should work. From a Streams perspective, it's no difference if you run
multiple threads within one {{KafkaStreams}} instance, or multiple
{{KafkaStreams}} instances within one JVM, or multiple JVMs (with one
{{KafkaStreams}} instance) on the same host. This should all work, including
any combination... How many threads to you use? If you run with a single
thread, with a single {{KafkaStreams}} instance the issue cannot occur as you
need at least two threads running -- this would explain why the lock issues is
exposes by your bug starting multiple instances. Anyway, as mentioned above,
please upgrade to {{0.10.2.1}} -- we fixed couple of lock issues their.
> add max_number _of_retries to exponential backoff strategy
> ----------------------------------------------------------
>
> Key: KAFKA-5242
> URL: https://issues.apache.org/jira/browse/KAFKA-5242
> Project: Kafka
> Issue Type: Improvement
> Components: streams
> Affects Versions: 0.10.2.0
> Reporter: Lukas Gemela
> Priority: Minor
> Attachments: clio_170511.log
>
>
> From time to time, during relabance we are getting a lot of exceptions saying
> {code}
> org.apache.kafka.streams.errors.LockException: task [0_0] Failed to lock the
> state directory: /app/db/clio/0_0
> at
> org.apache.kafka.streams.processor.internals.ProcessorStateManager.<init>(ProcessorStateManager.java:102)
> ~[kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.AbstractTask.<init>(AbstractTask.java:73)
> ~[kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.StreamTask.<init>(StreamTask.java:108)
> ~[kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.StreamThread.createStreamTask(StreamThread.java:834)
> ~[kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.StreamThread$TaskCreator.createTask(StreamThread.java:1207)
> ~[kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.StreamThread$AbstractTaskCreator.retryWithBackoff(StreamThread.java:1180)
> [kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.StreamThread.addStreamTasks(StreamThread.java:937)
> [kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.StreamThread.access$500(StreamThread.java:69)
> [kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.StreamThread$1.onPartitionsAssigned(StreamThread.java:236)
> [kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.onJoinComplete(ConsumerCoordinator.java:255)
> [kafka-clients-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.clients.consumer.internals.AbstractCoordinator.joinGroupIfNeeded(AbstractCoordinator.java:339)
> [kafka-clients-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureActiveGroup(AbstractCoordinator.java:303)
> [kafka-clients-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.poll(ConsumerCoordinator.java:286)
> [kafka-clients-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:1030)
> [kafka-clients-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:995)
> [kafka-clients-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:582)
> [kafka-streams-0.10.2.0.jar!/:?]
> at
> org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:368)
> [kafka-streams-0.10.2.0.jar!/:?]
> {code}
> (see attached logfile)
> It was actually problem on our side - we ran startStreams() twice and
> therefore we had two threads touching the same folder structure.
> But what I've noticed, the backoff strategy in
> StreamThread$AbstractTaskCreator.retryWithBackoff can run endlessly - after
> 20 iterations it takes 6hours until the next attempt to start a task.
> I've noticed latest code contains check for rebalanceTimeoutMs, but that
> still does not solve the problem especially in case
> MAX_POLL_INTERVAL_MS_CONFIG is set to Integer.MAX_INT. at this stage kafka
> streams just hangs up indefinitely.
> I would personally make that backoffstrategy a bit more configurable with a
> number of retries that if it exceed a configured value it propagates the
> exception as any other exception to custom client exception handler.
> (I can provide a patch)
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