Hot Thread Wheel Timer


(Clay Gorman) #1

Hello all,

I see on and off when I query hot_threads the following

  0.0% (193.2micros out of 500ms) cpu usage by thread 'elasticsearch[CLIENT_02][transport_client_timer][T#1]{Hashed wheel timer #1}'
     10/10 snapshots sharing following 5 elements
       java.lang.Thread.sleep(Native Method)
       org.jboss.netty.util.HashedWheelTimer$Worker.waitForNextTick(HashedWheelTimer.java:445)
       org.jboss.netty.util.HashedWheelTimer$Worker.run(HashedWheelTimer.java:364)
       org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108)
       java.lang.Thread.run(Thread.java:745)

It seems like a "notice" and nothing to worry about but was curious if anyone had an insight on that. My client, master and data nodes all seem to show this error on and off.

Thanks,
Clay


(Jörg Prante) #2

The hashed wheel timer is a feature of Netty. ES uses Netty, and Netty sometimes needs to wait for a short time.

For more information see http://netty.io/wiki/using-as-a-generic-library.html#wiki-h3-12


(Clay Gorman) #3

Great, thanks!


(system) #4