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https://issues.apache.org/jira/browse/CASSANDRA-13652?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16083702#comment-16083702
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Branimir Lambov commented on CASSANDRA-13652:
---------------------------------------------
bq. Yes. But such other useages will eat permit and Manager Thread will be
blocked in our code.
This is only relevant if the eating happens before checking we need to park and
actually calling {{LockSupport.park()}}. This is indeed possible for the line
130 call, which is why it should be removed and the control allowed to continue
to the checked park on line 146.
> Deadlock in AbstractCommitLogSegmentManager
> -------------------------------------------
>
> Key: CASSANDRA-13652
> URL: https://issues.apache.org/jira/browse/CASSANDRA-13652
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Reporter: Fuud
>
> AbstractCommitLogManager uses LockSupport.(un)park incorreclty. It invokes
> unpark without checking if manager thread was parked in approriate place.
> For example, logging frameworks uses queues and queues uses ReadWriteLock's
> that uses LockSupport. Therefore AbstractCommitLogManager.wakeManager can
> wake thread inside Lock and manager thread will sleep forever at park()
> method (because unpark permit was already consumed inside lock).
> For examle stack traces:
> {code}
> "MigrationStage:1" id=412 state=WAITING
> at sun.misc.Unsafe.park(Native Method)
> at java.util.concurrent.locks.LockSupport.park(LockSupport.java:304)
> at
> org.apache.cassandra.utils.concurrent.WaitQueue$AbstractSignal.awaitUninterruptibly(WaitQueue.java:279)
> at
> org.apache.cassandra.db.commitlog.AbstractCommitLogSegmentManager.awaitAvailableSegment(AbstractCommitLogSegmentManager.java:263)
> at
> org.apache.cassandra.db.commitlog.AbstractCommitLogSegmentManager.advanceAllocatingFrom(AbstractCommitLogSegmentManager.java:237)
> at
> org.apache.cassandra.db.commitlog.AbstractCommitLogSegmentManager.forceRecycleAll(AbstractCommitLogSegmentManager.java:279)
> at
> org.apache.cassandra.db.commitlog.CommitLog.forceRecycleAllSegments(CommitLog.java:210)
> at org.apache.cassandra.config.Schema.dropView(Schema.java:708)
> at
> org.apache.cassandra.schema.SchemaKeyspace.lambda$updateKeyspace$23(SchemaKeyspace.java:1361)
> at
> org.apache.cassandra.schema.SchemaKeyspace$$Lambda$382/1123232162.accept(Unknown
> Source)
> at java.util.LinkedHashMap$LinkedValues.forEach(LinkedHashMap.java:608)
> at
> java.util.Collections$UnmodifiableCollection.forEach(Collections.java:1080)
> at
> org.apache.cassandra.schema.SchemaKeyspace.updateKeyspace(SchemaKeyspace.java:1361)
> at
> org.apache.cassandra.schema.SchemaKeyspace.mergeSchema(SchemaKeyspace.java:1332)
> at
> org.apache.cassandra.schema.SchemaKeyspace.mergeSchemaAndAnnounceVersion(SchemaKeyspace.java:1282)
> - locked java.lang.Class@cc38904
> at
> org.apache.cassandra.db.DefinitionsUpdateVerbHandler$1.runMayThrow(DefinitionsUpdateVerbHandler.java:51)
> at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
> at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at
> org.apache.cassandra.concurrent.DebuggableThreadPoolExecutor$LocalSessionWrapper.run(DebuggableThreadPoolExecutor.java:322)
> at
> com.ringcentral.concurrent.executors.MonitoredRunnable.run(MonitoredRunnable.java:36)
> at MON_R_MigrationStage.run(NamedRunnableFactory.java:67)
> at
> com.ringcentral.concurrent.executors.MonitoredThreadPoolExecutor$MdcAwareRunnable.run(MonitoredThreadPoolExecutor.java:114)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> at
> org.apache.cassandra.concurrent.NamedThreadFactory.lambda$threadLocalDeallocator$0(NamedThreadFactory.java:79)
> at
> org.apache.cassandra.concurrent.NamedThreadFactory$$Lambda$61/1733339045.run(Unknown
> Source)
> at java.lang.Thread.run(Thread.java:745)
> "COMMIT-LOG-ALLOCATOR:1" id=80 state=WAITING
> at sun.misc.Unsafe.park(Native Method)
> at java.util.concurrent.locks.LockSupport.park(LockSupport.java:304)
> at
> org.apache.cassandra.db.commitlog.AbstractCommitLogSegmentManager$1.runMayThrow(AbstractCommitLogSegmentManager.java:128)
> at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
> at
> org.apache.cassandra.concurrent.NamedThreadFactory.lambda$threadLocalDeallocator$0(NamedThreadFactory.java:79)
> at
> org.apache.cassandra.concurrent.NamedThreadFactory$$Lambda$61/1733339045.run(Unknown
> Source)
> at java.lang.Thread.run(Thread.java:745)
> {code}
> Solution is to use Semaphore instead of low-level LockSupport.
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