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Toshihiro Suzuki commented on HBASE-21200: ------------------------------------------ No error occurs in the test. Just the reversed scan is very slow. I will need to improve the test, but what I wanted to show in the test is that the similar issue to HBASE-15871 is reproduced by the above steps. And that causes very slow reversed scan. > Memstore flush doesn't finish because of seekToPreviousRow() in memstore > scanner. > --------------------------------------------------------------------------------- > > Key: HBASE-21200 > URL: https://issues.apache.org/jira/browse/HBASE-21200 > Project: HBase > Issue Type: Bug > Components: Scanners > Reporter: dongjin2193.jeon > Priority: Major > Attachments: HBASE-21200-UT.patch, RegionServerJstack.log > > > The issue of delaying memstore flush still occurs after backport hbase-15871. > Reverse scan takes a long time to seek previous row in the memstore full of > deleted cells. > > jstack : > "MemStoreFlusher.0" #114 prio=5 os_prio=0 tid=0x00007fa3d0729000 nid=0x486a > waiting on condition [0x00007fa3b9b6b000] > java.lang.Thread.State: WAITING (parking) > at sun.misc.Unsafe.park(Native Method) > - parking to wait for <0x00000000a465fe60> (a > java.util.concurrent.locks.ReentrantLock$NonfairSync) > at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) > at > java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836) > at > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870) > at > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199) > at > java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209) > at > java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285) > at > org.apache.hadoop.hbase.regionserver.*StoreScanner.updateReaders(StoreScanner.java:695)* > at > org.apache.hadoop.hbase.regionserver.HStore.notifyChangedReadersObservers(HStore.java:1127) > at > org.apache.hadoop.hbase.regionserver.HStore.updateStorefiles(HStore.java:1106) > at > org.apache.hadoop.hbase.regionserver.HStore.access$600(HStore.java:130) > at > org.apache.hadoop.hbase.regionserver.HStore$StoreFlusherImpl.commit(HStore.java:2455) > at > org.apache.hadoop.hbase.regionserver.HRegion.internalFlushCacheAndCommit(HRegion.java:2519) > at > org.apache.hadoop.hbase.regionserver.HRegion.internalFlushcache(HRegion.java:2256) > at > org.apache.hadoop.hbase.regionserver.HRegion.internalFlushcache(HRegion.java:2218) > at > org.apache.hadoop.hbase.regionserver.HRegion.flushcache(HRegion.java:2110) > at > org.apache.hadoop.hbase.regionserver.HRegion.flush(HRegion.java:2036) > at > org.apache.hadoop.hbase.regionserver.MemStoreFlusher.flushRegion(MemStoreFlusher.java:501) > at > org.apache.hadoop.hbase.regionserver.MemStoreFlusher.flushRegion(MemStoreFlusher.java:471) > at > org.apache.hadoop.hbase.regionserver.MemStoreFlusher.access$800(MemStoreFlusher.java:75) > at > org.apache.hadoop.hbase.regionserver.MemStoreFlusher$FlushHandler.run(MemStoreFlusher.java:259) > at java.lang.Thread.run(Thread.java:748) > > "RpcServer.FifoWFPBQ.default.handler=27,queue=0,port=16020" #65 daemon prio=5 > os_prio=0 tid=0x00007fa3e6280000 nid=0x4801 runnable [0x00007fa3bd29a000] > java.lang.Thread.State: RUNNABLE > at > org.apache.hadoop.hbase.regionserver.DefaultMemStore$MemStoreScanner.getNext(DefaultMemStore.java:780) > at > org.apache.hadoop.hbase.regionserver.DefaultMemStore$MemStoreScanner.seekInSubLists(DefaultMemStore.java:826) > - locked <0x00000000b45aa5b8> (a > org.apache.hadoop.hbase.regionserver.DefaultMemStore$MemStoreScanner) > at > org.apache.hadoop.hbase.regionserver.DefaultMemStore$MemStoreScanner.seek(DefaultMemStore.java:818) > - locked <0x00000000b45aa5b8> (a > org.apache.hadoop.hbase.regionserver.DefaultMemStore$MemStoreScanner) > at > org.apache.hadoop.hbase.regionserver.DefaultMemStore$MemStoreScanner.seekToPreviousRow(DefaultMemStore.java:1000) > - locked <0x00000000b45aa5b8> (a > org.apache.hadoop.hbase.regionserver.DefaultMemStore$MemStoreScanner) > at > org.apache.hadoop.hbase.regionserver.ReversedKeyValueHeap.next(ReversedKeyValueHeap.java:136) > at > org.apache.hadoop.hbase.regionserver.*StoreScanner.next(StoreScanner.java:629)* > at > org.apache.hadoop.hbase.regionserver.KeyValueHeap.next(KeyValueHeap.java:147) > at > org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.populateResult(HRegion.java:5876) > at > org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextInternal(HRegion.java:6027) > at > org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextRaw(HRegion.java:5814) > at > org.apache.hadoop.hbase.regionserver.RSRpcServices.scan(RSRpcServices.java:2552) > - locked <0x000000009ee8ca10> (a > org.apache.hadoop.hbase.regionserver.ReversedRegionScannerImpl) > at > org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ClientService$2.callBlockingMethod(ClientProtos.java:32385) > at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2150) > at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:112) > at > org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:187) > at > org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:167) -- This message was sent by Atlassian JIRA (v7.6.3#76005)