I have 5 threads writing json blob to hdfs but what I see is application hanging and when I do the thread dump on the application I see threads waiting on epollWait:
"New I/O client worker #5-1" daemon prio=10 tid=0x00002aaac81e3000 nid=0x7080 runnable [0x000000004395c000] java.lang.Thread.State: RUNNABLE at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method) at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:210) at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:65) at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69) - locked <0x000000060c3cc170> (a sun.nio.ch.Util$2) - locked <0x000000060c3cc160> (a java.util.Collections$UnmodifiableSet) - locked <0x000000060c3cbf58> (a sun.nio.ch.EPollSelectorImpl) at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80) at org.jboss.netty.channel.socket.nio.SelectorUtil.select(SelectorUtil.java:38) at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:165) at org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108) at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:44) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:662)