Find the Java Thread that is hogging your CPU

javahog.sh

# first find the process using top
top -H

# find the java process
top - 15:32:53 up 1 day,  2:20,  1 user,  load average: 1.28, 1.17, 1.18
Tasks: 2355 total,   2 running, 2353 sleeping,   0 stopped,   0 zombie
Cpu(s): 26.4%us,  1.4%sy,  0.0%ni, 66.1%id,  5.7%wa,  0.0%hi,  0.2%si,  0.2%st
Mem:  16332248k total,  9613508k used,  6718740k free,   312148k buffers
Swap:  1048572k total,        0k used,  1048572k free,  1858716k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
29678 yourmom   20   0 5521m  23m 8112 R 94.6  0.1   7:00.19 java

# use jstack to dump the jvm threads
jstack 29678

# the jvm provides the native pid as nid but in HEX: 29678 -> 0x73EE
# search for 0x73EE finds the thread hogging the CPU
"pool-1-thread-3" prio=10 tid=0x00009fa2ac0b5800 nid=0x73EE runnable [0x00009fa439df1000]
   java.lang.Thread.State: RUNNABLE
	at BossHog$Hog.run(BossHog.java:19)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:744)