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https://issues.apache.org/jira/browse/HBASE-16429?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
stack updated HBASE-16429:
--------------------------
Status: Patch Available (was: Open)
> FSHLog: deadlock if rollWriter called when ring buffer filled with appends
> --------------------------------------------------------------------------
>
> Key: HBASE-16429
> URL: https://issues.apache.org/jira/browse/HBASE-16429
> Project: HBase
> Issue Type: Bug
> Affects Versions: 1.2.2, 1.1.2
> Reporter: Yu Li
> Assignee: Yu Li
> Priority: Critical
> Attachments: HBASE-16429.patch
>
>
> Recently we experienced an online problem that all handlers are stuck.
> Checking the jstack we could see all handler threads waiting for
> RingBuffer.next, while the single ring buffer consumer dead waiting for
> {{safePointReleasedLatch}} to count down:
> {noformat}
> Normal handler thread:
> "B.defaultRpcServer.handler=126,queue=9,port=16020" daemon prio=10
> tid=0x00007efd4b44f800 nid=0x15f29 runnable [0x00007efd3db7b000]
> java.lang.Thread.State: TIMED_WAITING (parking)
> at sun.misc.Unsafe.park(Native Method)
> at
> java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:349)
> at
> com.lmax.disruptor.MultiProducerSequencer.next(MultiProducerSequencer.java:136)
> at
> com.lmax.disruptor.MultiProducerSequencer.next(MultiProducerSequencer.java:105)
> at com.lmax.disruptor.RingBuffer.next(RingBuffer.java:246)
> at
> org.apache.hadoop.hbase.regionserver.wal.FSHLog.append(FSHLog.java:1222)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.doMiniBatchMutation(HRegion.java:3188)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.batchMutate(HRegion.java:2879)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.batchMutate(HRegion.java:2819)
> at
> org.apache.hadoop.hbase.regionserver.RSRpcServices.doBatchOp(RSRpcServices.java:736)
> at
> org.apache.hadoop.hbase.regionserver.RSRpcServices.doNonAtomicRegionMutation(RSRpcServices.java:698)
> at
> org.apache.hadoop.hbase.regionserver.RSRpcServices.multi(RSRpcServices.java:2095)
> at
> org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ClientService$2.callBlockingMethod(ClientProtos.java:32213)
> at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:774)
> at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:102)
> at
> org.apache.hadoop.hbase.ipc.RpcExecutor.consumerLoop(RpcExecutor.java:133)
> at org.apache.hadoop.hbase.ipc.RpcExecutor$1.run(RpcExecutor.java:108)
> at java.lang.Thread.run(Thread.java:756)
> RingBufferEventHandler thread waiting for safePointReleasedLatch:
> "regionserver/hadoop0369.et2.tbsite.net/11.251.152.226:16020.append-pool2-t1"
> prio=10 tid=0x00007efd320d0000 nid=0x1777b waiting on condition
> [0x00007efd2d2fa000]
> java.lang.Thread.State: WAITING (parking)
> at sun.misc.Unsafe.park(Native Method)
> - parking to wait for <0x00007f01b48d9178> (a
> java.util.concurrent.CountDownLatch$Sync)
> at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:994)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1303)
> at java.util.concurrent.CountDownLatch.await(CountDownLatch.java:236)
> at
> org.apache.hadoop.hbase.regionserver.wal.FSHLog$SafePointZigZagLatch.safePointAttained(FSHLog.java:1866)
> at
> org.apache.hadoop.hbase.regionserver.wal.FSHLog$RingBufferEventHandler.attainSafePoint(FSHLog.java:2066)
> at
> org.apache.hadoop.hbase.regionserver.wal.FSHLog$RingBufferEventHandler.onEvent(FSHLog.java:2029)
> at
> org.apache.hadoop.hbase.regionserver.wal.FSHLog$RingBufferEventHandler.onEvent(FSHLog.java:1909)
> at
> com.lmax.disruptor.BatchEventProcessor.run(BatchEventProcessor.java:128)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> at java.lang.Thread.run(Thread.java:756)
> {noformat}
> {{FSHLog#replaceWriter}} will call {{SafePointZigZagLatch#releaseSafePoint}}
> to count down {{safePointReleasedLatch}}, but replaceWriter got stuck when
> trying to publish a sync onto ring buffer:
> {noformat}
> "regionserver/hadoop0369.et2.tbsite.net/11.251.152.226:16020.logRoller"
> daemon prio=10 tid=0x00007efd320c8800 nid=0x16123 runnable
> [0x00007efd311f6000]
> java.lang.Thread.State: TIMED_WAITING (parking)
> at sun.misc.Unsafe.park(Native Method)
> at
> java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:349)
> at
> com.lmax.disruptor.MultiProducerSequencer.next(MultiProducerSequencer.java:136)
> at
> com.lmax.disruptor.MultiProducerSequencer.next(MultiProducerSequencer.java:105)
> at com.lmax.disruptor.RingBuffer.next(RingBuffer.java:246)
> at
> org.apache.hadoop.hbase.regionserver.wal.FSHLog.publishSyncOnRingBuffer(FSHLog.java:1481)
> at
> org.apache.hadoop.hbase.regionserver.wal.FSHLog.publishSyncOnRingBuffer(FSHLog.java:1477)
> at
> org.apache.hadoop.hbase.regionserver.wal.FSHLog.replaceWriter(FSHLog.java:957)
> at
> org.apache.hadoop.hbase.regionserver.wal.FSHLog.rollWriter(FSHLog.java:726)
> at
> org.apache.hadoop.hbase.regionserver.LogRoller.run(LogRoller.java:148)
> at java.lang.Thread.run(Thread.java:756)
> {noformat}
> Thus deadlock happens.
> A brief process of how deadlock forms:
> {noformat}
> ring buffer filled with appends
> -> rollWriter happens
> -> the only consumer of ring buffer waiting for safePointReleasedLatch
> -> rollWriter cannot publish sync since ring buffer is full
> -> rollWriter won't release safePointReleasedLatch
> {noformat}
> This JIRA targeting at resolve this issue, and will add a UT to cover the case
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