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https://issues.apache.org/jira/browse/CASSANDRA-10815?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Sylvain Lebresne updated CASSANDRA-10815:
-----------------------------------------
Fix Version/s: 3.x
2.2.x
2.1.x
> WrappingCompactionStrategy can block others when there are lots of sstables
> ---------------------------------------------------------------------------
>
> Key: CASSANDRA-10815
> URL: https://issues.apache.org/jira/browse/CASSANDRA-10815
> Project: Cassandra
> Issue Type: Bug
> Components: Compaction
> Reporter: Severin Leonhardt
> Fix For: 2.1.x, 2.2.x, 3.x
>
>
> We observe {{nodetool compactionstats}} hanging when there are a lot of
> SSTables in one table. We have about 30.000 SSTables most likely created by
> an incremental repair (why it's that many is still a mystery to us).
> Looking at the stacktraces of some selected threads it becomes apparent that
> a single CompactionExecutor blocks several other threads:
> {noformat}
> "CompactionExecutor:4065" - Thread t@282454
> java.lang.Thread.State: RUNNABLE
> at java.util.TimSort.binarySort(TimSort.java:292)
> at java.util.TimSort.sort(TimSort.java:235)
> at java.util.Arrays.sort(Arrays.java:1512)
> at java.util.ArrayList.sort(ArrayList.java:1454)
> at java.util.Collections.sort(Collections.java:175)
> at
> org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy.trimToThresholdWithHotness(SizeTieredCompactionStrategy.java:139)
> at
> org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy.mostInterestingBucket(SizeTieredCompactionStrategy.java:119)
> at
> org.apache.cassandra.db.compaction.LeveledManifest.getSSTablesForSTCS(LeveledManifest.java:360)
> at
> org.apache.cassandra.db.compaction.LeveledManifest.getCompactionCandidates(LeveledManifest.java:318)
> - locked <25446e7b> (a
> org.apache.cassandra.db.compaction.LeveledManifest)
> at
> org.apache.cassandra.db.compaction.LeveledCompactionStrategy.getMaximalTask(LeveledCompactionStrategy.java:101)
> at
> org.apache.cassandra.db.compaction.LeveledCompactionStrategy.getNextBackgroundTask(LeveledCompactionStrategy.java:90)
> - locked <33506169> (a
> org.apache.cassandra.db.compaction.LeveledCompactionStrategy)
> at
> org.apache.cassandra.db.compaction.WrappingCompactionStrategy.getNextBackgroundTask(WrappingCompactionStrategy.java:77)
> - locked <31924612> (a
> org.apache.cassandra.db.compaction.WrappingCompactionStrategy)
> at
> org.apache.cassandra.db.compaction.CompactionManager$BackgroundCompactionCandidate.run(CompactionManager.java:230)
> at
> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> at java.lang.Thread.run(Thread.java:745)
> {noformat}
> Because this thread has locked <31924612> (a
> org.apache.cassandra.db.compaction.WrappingCompactionStrategy) the following
> threads are blocked:
> {noformat}
> "CompactionExecutor:4064" - Thread t@282337
> java.lang.Thread.State: BLOCKED
> at
> org.apache.cassandra.db.compaction.WrappingCompactionStrategy.getNextBackgroundTask(WrappingCompactionStrategy.java:72)
> - waiting to lock <31924612> (a
> org.apache.cassandra.db.compaction.WrappingCompactionStrategy) owned by
> "CompactionExecutor:4065" t@282454
> at
> org.apache.cassandra.db.compaction.CompactionManager$BackgroundCompactionCandidate.run(CompactionManager.java:230)
> at
> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> at java.lang.Thread.run(Thread.java:745)
> {noformat}
> {noformat}
> "MemtableFlushWriter:2431" - Thread t@283411
> java.lang.Thread.State: BLOCKED
> at
> org.apache.cassandra.db.compaction.WrappingCompactionStrategy.handleNotification(WrappingCompactionStrategy.java:250)
> - waiting to lock <31924612> (a
> org.apache.cassandra.db.compaction.WrappingCompactionStrategy) owned by
> "CompactionExecutor:4065" t@282454
> at org.apache.cassandra.db.DataTracker.notifyAdded(DataTracker.java:518)
> at
> org.apache.cassandra.db.DataTracker.replaceFlushed(DataTracker.java:178)
> at
> org.apache.cassandra.db.compaction.AbstractCompactionStrategy.replaceFlushed(AbstractCompactionStrategy.java:234)
> at
> org.apache.cassandra.db.ColumnFamilyStore.replaceFlushed(ColumnFamilyStore.java:1541)
> at
> org.apache.cassandra.db.Memtable$FlushRunnable.runMayThrow(Memtable.java:336)
> at
> org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
> at
> com.google.common.util.concurrent.MoreExecutors$SameThreadExecutorService.execute(MoreExecutors.java:297)
> at
> org.apache.cassandra.db.ColumnFamilyStore$Flush.run(ColumnFamilyStore.java:1154)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> at java.lang.Thread.run(Thread.java:745)
> {noformat}
> {noformat}
> "RMI TCP Connection(128577)-192.168.0.1" - Thread t@282977
> java.lang.Thread.State: BLOCKED
> at
> org.apache.cassandra.db.compaction.WrappingCompactionStrategy.getEstimatedRemainingTasks(WrappingCompactionStrategy.java:147)
> - waiting to lock <31924612> (a
> org.apache.cassandra.db.compaction.WrappingCompactionStrategy) owned by
> "CompactionExecutor:4065" t@282454
> at
> org.apache.cassandra.metrics.CompactionMetrics$1.value(CompactionMetrics.java:65)
> at
> org.apache.cassandra.metrics.CompactionMetrics$1.value(CompactionMetrics.java:57)
> at
> com.yammer.metrics.reporting.JmxReporter$Gauge.getValue(JmxReporter.java:63)
> at sun.reflect.GeneratedMethodAccessor31.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:497)
> at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
> at sun.reflect.GeneratedMethodAccessor19.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:497)
> at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
> at
> com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:112)
> at
> com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:46)
> at
> com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:237)
> at
> com.sun.jmx.mbeanserver.PerInterface.getAttribute(PerInterface.java:83)
> at
> com.sun.jmx.mbeanserver.MBeanSupport.getAttribute(MBeanSupport.java:206)
> at
> com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getAttribute(DefaultMBeanServerInterceptor.java:647)
> at
> com.sun.jmx.mbeanserver.JmxMBeanServer.getAttribute(JmxMBeanServer.java:678)
> at
> com.sun.jmx.remote.security.MBeanServerAccessController.getAttribute(MBeanServerAccessController.java:320)
> at
> javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1443)
> at
> javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
> at
> javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1307)
> at java.security.AccessController.doPrivileged(Native Method)
> at
> javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1406)
> at
> javax.management.remote.rmi.RMIConnectionImpl.getAttribute(RMIConnectionImpl.java:637)
> at sun.reflect.GeneratedMethodAccessor21.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:497)
> at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:323)
> at sun.rmi.transport.Transport$1.run(Transport.java:200)
> at sun.rmi.transport.Transport$1.run(Transport.java:197)
> at java.security.AccessController.doPrivileged(Native Method)
> at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
> at
> sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
> at
> sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
> at
> sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$241(TCPTransport.java:683)
> at
> sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$$Lambda$1/183345253.run(Unknown
> Source)
> at java.security.AccessController.doPrivileged(Native Method)
> at
> sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> at java.lang.Thread.run(Thread.java:745)
> {noformat}
> The lock protects from concurrent access through the two synchronized methods
> WrappingCompactionStrategy.getEstimatedRemainingTasks and
> WrappingCompactionStrategy.getNextBackgroundTask.
> The lock is not just hold for a short time but for several minutes. We think
> that this combined with suboptimal values for {{memtable_flush_writers}} and
> {{concurrent_compactors}} caused our nodes to exhaust their heap and die
> after running incremental repair.
> There also seems to be no other way to reduce the number of SSTables as a
> user except than waiting for the compactions to eventually finish which looks
> like it can take days.
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