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HBase, mail # user - Handlers being blocked during reads


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Re: Handlers being blocked during reads
Esteban Gutierrez 2013-07-30, 03:31
Hi Pablo,
What do you see in the logs around the time you saw that behavior? is
this happening on a single Region Server? what version of HBase are
you running?

cheers,
Esteban.

Cloudera, Inc.

On Jul 29, 2013, at 20:21, Pablo Medina <[EMAIL PROTECTED]> wrote:

> Hi all,
>
> I'm having a lot of handlers (90 - 300 aprox) being blocked when reading
> rows. They are blocked during changedReaderObserver registration.
> Does anybody else run into the same issue?
>
> 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)
>
> Thanks,
> Pablo.