Why do you say they are waiting? They are in Runnable state. That said this seems to be due to this: https://github.com/netty/netty/issues/327
I am not sure if this is the same issue, but 100% CPU can be caused by the above. Hari -- Hari Shreedharan On Wednesday, August 22, 2012 at 12:54 PM, Mohit Anchlia wrote: > 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)
