Unusual threads seen in a thread dump (Doc ID 1680529.1)

Last updated on NOVEMBER 03, 2016

Applies to:

Oracle WebCenter Sites - Version 7.6.2 and later
Information in this document applies to any platform.

Goal

Thread dumps show these threads, is this indicative of a problem? What do they do?

a)
  "net.sf.ehcache.CacheManager@991f7f1b" id=50 idx=0xfc tid=64 prio=5 alive, waiting, native_blocked, daemon
  -- Waiting for notification on: java/util/TaskQueue@0x3f9d2b958[fat lock]
  at jrockit/vm/Threads.waitForNotifySignal(JLjava/lang/Object;)Z(Native Method)
  at java/lang/Object.wait(J)V(Native Method)
  at java/util/TimerThread.mainLoop(Timer.java:509)
  ^-- Lock released while waiting: java/util/TaskQueue@0x3f9d2b958[fat lock]
  at java/util/TimerThread.run(Timer.java:462)
  at jrockit/vm/RNI.c2java(JJJJJ)V(Native Method)
  -- end of trace

b)
  "Store dependencyRepository Spool Thread" id=51 idx=0x100 tid=65 prio=5 alive, sleeping, native_waiting, daemon
  at java/lang/Thread.sleep(J)V(Native Method)
  at net/sf/ehcache/store/DiskStore.spoolAndExpiryThreadMain(DiskStore.java:634)
  at net/sf/ehcache/store/DiskStore.access$900(DiskStore.java:68)
  at net/sf/ehcache/store/DiskStore$SpoolAndExpiryThread.run(DiskStore.java:1110)
  at jrockit/vm/RNI.c2java(JJJJJ)V(Native Method)
  -- end of trace

c)
  "DiagnosticsHandler,WCS_Cluster,127.0.0.1:34168" id=102 idx=0x1c8 tid=115 prio=5 alive, native_blocked, daemon
  at java/net/PlainDatagramSocketImpl.receive0(Ljava/net/DatagramPacket;)V(Native Method)
  ^-- Holding lock: java/net/PlainDatagramSocketImpl@0x3fc900b08[recursive]
  at java/net/PlainDatagramSocketImpl.receive(PlainDatagramSocketImpl.java:145)
  ^-- Holding lock: java/net/PlainDatagramSocketImpl@0x3fc900b08[thin lock]
  at java/net/DatagramSocket.receive(DatagramSocket.java:725)
  ^-- Holding lock: java/net/DatagramPacket@0x3fc900958[thin lock]
  ^-- Holding lock: java/net/MulticastSocket@0x3fc900ad0[thin lock]
  at org/jgroups/protocols/TP$DiagnosticsHandler.run(TP.java:1944)
  at java/lang/Thread.run(Thread.java:662)
  at jrockit/vm/RNI.c2java(JJJJJ)V(Native Method)
  -- end of trace

d)
  "UDP ucast,WCS_Cluster,127.0.0.1:34168" id=103 idx=0x1cc tid=116 prio=5 alive, native_blocked
  at java/net/PlainDatagramSocketImpl.receive0(Ljava/net/DatagramPacket;)V(Native Method)
  ^-- Holding lock: java/net/PlainDatagramSocketImpl@0x3fc909a40[recursive]
  at java/net/PlainDatagramSocketImpl.receive(PlainDatagramSocketImpl.java:145)
  ^-- Holding lock: java/net/PlainDatagramSocketImpl@0x3fc909a40[thin lock]
  at java/net/DatagramSocket.receive(DatagramSocket.java:725)
  ^-- Holding lock: java/net/DatagramPacket@0x3fc9007e0[thin lock]
  ^-- Holding lock: java/net/DatagramSocket@0x3fc909a18[thin lock]
  at org/jgroups/protocols/UDP$UcastReceiver.run(UDP.java:891)
  at java/lang/Thread.run(Thread.java:662)
  at jrockit/vm/RNI.c2java(JJJJJ)V(Native Method)
  -- end of trace
 

Solution

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