Details
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Bug
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Status: Closed
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Major
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Resolution: Fixed
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0.94.7, 0.95.1
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None
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Reviewed
Description
I'm having a lot of handlers (90 - 300 aprox) being blocked when reading rows. They are blocked during changedReaderObserver registration.
Lars Hofhansl suggests to change the implementation of changedReaderObserver from CopyOnWriteList to ConcurrentHashMap.
Here is a stack trace:
"IPC Server handler 99 on 60020" daemon prio=10 tid=0x0000000041c84000 nid=0x2244 waiting on condition [0x00007ff51fefd000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000c5c13ae8> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:842)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1178)
at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:186)
at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:262)
at java.util.concurrent.CopyOnWriteArrayList.addIfAbsent(CopyOnWriteArrayList.java:553)
at java.util.concurrent.CopyOnWriteArraySet.add(CopyOnWriteArraySet.java:221)
at org.apache.hadoop.hbase.regionserver.Store.addChangedReaderObserver(Store.java:1085)
at org.apache.hadoop.hbase.regionserver.StoreScanner.<init>(StoreScanner.java:138)
at org.apache.hadoop.hbase.regionserver.Store.getScanner(Store.java:2077)
at org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.<init>(HRegion.java:3755)
at org.apache.hadoop.hbase.regionserver.HRegion.instantiateRegionScanner(HRegion.java:1804)
at org.apache.hadoop.hbase.regionserver.HRegion.getScanner(HRegion.java:1796)
at org.apache.hadoop.hbase.regionserver.HRegion.getScanner(HRegion.java:1771)
at org.apache.hadoop.hbase.regionserver.HRegion.get(HRegion.java:4776)
at org.apache.hadoop.hbase.regionserver.HRegion.get(HRegion.java:4750)
at org.apache.hadoop.hbase.regionserver.HRegionServer.get(HRegionServer.java:2152)
at org.apache.hadoop.hbase.regionserver.HRegionServer.multi(HRegionServer.java:3700)
at sun.reflect.GeneratedMethodAccessor26.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.hbase.ipc.WritableRpcEngine$Server.call(WritableRpcEngine.java:320)
at org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:1426)