How to prevent or remove orphaned IBM J9VM process programmatically

Question

Hi all,

I would like to know if there is a way to, if best, prevent, or otherwise remove orphaned IBMJ9VM programmatically. It is mentioned in IBM's documentation that doing a CTRL-C will create orphan JVM process.

Nicholas

Answer 1

Could you provide platform details & a doclink to the orphan JVM info? This doesn't seem fully consistent with my experience (as a J9 developer ).

Answer 2

Hi Trent,

I'm using the wsadmin shell that is bundled together with WAS7.0 and tested with this simple piece of Jython code (TestThread.py) on my Windows Server 2003 32-bit machine

import threading
import time
import thread

def handler():
    for i in range(200):
        time.sleep(5)
        print "Hi!"

t = threading.Thread(target=handler)
t.start()

while the program is running, I tried to kill it with CTRL-C and I found an orphan IBM JVM process in the process tree when the console prompted me if I want to terminate the batch job.

This is how I invoked the Jython code:

C:\Program Files\WebSphere\profiles\AppSrv01\bin>wsadmin -lang jython -user USERNAME -password PASSWORD -f "TestThread.py"

This is how my JVM looks like:

C:\Program Files\WebSphere\java\bin>java -verbose:sizes -version
  -Xmca32K        RAM class segment increment
  -Xmco128K       ROM class segment increment
  -Xmns0K         initial new space size
  -Xmnx0K         maximum new space size
  -Xms4M          initial memory size
  -Xmos4M         initial old space size
  -Xmox1624995K   maximum old space size
  -Xmx1624995K    memory maximum
  -Xmr16K         remembered set size
  -Xlp4K          large page size
                  available large page sizes: 4K 4M
  -Xmso256K       operating system thread stack size
  -Xiss2K         java thread stack initial size
  -Xssi16K        java thread stack increment
  -Xss256K        java thread stack maximum size
java version "1.6.0"
Java(TM) SE Runtime Environment (build pwi3260sr6ifix-20091015_01(SR6+152211+155930+156106))
IBM J9 VM (build 2.4, JRE 1.6.0 IBM J9 2.4 Windows Server 2003 x86-32 jvmwi3260sr6-20091001_43491 (JIT enabled, AOT enabled)
J9VM - 20091001_043491
JIT  - r9_20090902_1330ifx1
GC   - 20090817_AA)
JCL  - 20091006_01

This is the URL you requested:

http://www.ibm.com/developerworks/java/jdk/linux/142/runtimeguide.lnx.en.html

Search for the word "orphaned" in the webpage