I tried it on my test server, but "kill -3 OpenfirePID" has no effect?

(I'm using Java 6....googling for "kill -3" finds only Java 1.3, 1.4, ...?)

>Openfire will likely log this in nohup.out.

ah...yes

Here the first four threads, sorted by time:

TIME      PID      TID     HexTID  PRI
03:33:24  17465  17467     443B    24
00:26:37  17465  17515     446B    24
00:04:59  17465  17530     447A    24
00:03:11  17465  17470     443E    21

Now the stack traces from nohup.out:

"VM Thread" prio=10 tid=0x09618c00 nid=0x443b runnable

"SocketAcceptorIoProcessor-1.0" prio=10 tid=0x09d6c800 nid=0x446b runnable [http://0x9f815000..0x9f8160b0|http://0x9f815000..0x9f8160b0]
   java.lang.Thread.State: RUNNABLE
        at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
        at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:215)
        at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:65)
        at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69)
        - locked <0xa2e9a200> (a sun.nio.ch.Util$1)
        - locked <0xa2e9a1f0> (a java.util.Collections$UnmodifiableSet)
        - locked <0xa2e9a0a8> (a sun.nio.ch.EPollSelectorImpl)
        at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80)
        at org.apache.mina.transport.socket.nio.SocketIoProcessor$Worker.run(SocketIoProce ssor.java:480)
        at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:51)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java: 885)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
        at java.lang.Thread.run(Thread.java:619)

"SocketAcceptorIoProcessor-2.0" prio=10 tid=0x0993d000 nid=0x447a runnable [http://0x9f37f000..0x9f37fe30|http://0x9f37f000..0x9f37fe30]
   java.lang.Thread.State: RUNNABLE
        at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
        at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:215)
        at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:65)
        at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69)
        - locked <0xa2f0e8a0> (a sun.nio.ch.Util$1)
        - locked <0xa2f0e8b0> (a java.util.Collections$UnmodifiableSet)
        - locked <0xa2f0e860> (a sun.nio.ch.EPollSelectorImpl)
        at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80)
        at org.apache.mina.transport.socket.nio.SocketIoProcessor$Worker.run(SocketIoProce ssor.java:480)
        at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:51)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java: 885)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
        at java.lang.Thread.run(Thread.java:619)

"Finalizer" daemon prio=10 tid=0x0961d000 nid=0x443e in Object.wait() [http://0xa08fe000..0xa08fefb0|http://0xa08fe000..0xa08fefb0]
   java.lang.Thread.State: WAITING (on object monitor)
        at java.lang.Object.wait(Native Method)
        - waiting on <0xa2a708e0> (a java.lang.ref.ReferenceQueue$Lock)
        at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:116)
        - locked <0xa2a708e0> (a java.lang.ref.ReferenceQueue$Lock)
        at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:132)
        at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:159)

I hope you can do something with that.