Hi All, HBase client waits indefinitely for performing any operation. On taking, jstack we saw all the threads waiting on BoundedCompletionService.take() call. The hconnection pool's stack is
hconnection-0x58ca857d-shared--pool1-t96" daemon prio=10 tid=0x00007f29d4510800 nid=0x84d0 waiting on condition [0x00007f2568dc0000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x000000060cbecf50> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2043) at java.util.concurrent.ArrayBlockingQueue.take(ArrayBlockingQueue.java:374) at org.apache.hadoop.hbase.util.BoundedCompletionService.take(BoundedCompletionService.java:74) at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:174) at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:56) at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:200) at org.apache.hadoop.hbase.client.ClientSmallReversedScanner.next(ClientSmallReversedScanner.java:145) at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegionInMeta(ConnectionManager.java:1200) at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1109) at org.apache.hadoop.hbase.client.AsyncProcess$AsyncRequestFutureImpl.findAllLocationsOrFail(AsyncProcess.java:916) at org.apache.hadoop.hbase.client.AsyncProcess$AsyncRequestFutureImpl.groupAndSendMultiAction(AsyncProcess.java:833) at org.apache.hadoop.hbase.client.AsyncProcess$AsyncRequestFutureImpl.resubmit(AsyncProcess.java:1156) at org.apache.hadoop.hbase.client.AsyncProcess$AsyncRequestFutureImpl.receiveMultiAction(AsyncProcess.java:1296) at org.apache.hadoop.hbase.client.AsyncProcess$AsyncRequestFutureImpl.access$1200(AsyncProcess.java:574) at org.apache.hadoop.hbase.client.AsyncProcess$AsyncRequestFutureImpl$SingleServerRequestRunnable.run(AsyncProcess.java:716) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask.run(FutureTask.java:262) 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:745) Our client configurations are as follows: hbase.hconnection.threads.core - 1 hbase.hconnection.threads.max - 10