How to list all Threads in the JVM? (Includes suggestion.)
Hi, We are trying to monitor the set of Threads in the JVM running Tomcat in order to fix a resource exhaustion problem we have. (Tomcat and/or our code is increasing the number of threads until the hard nproc limit in /etc/security/limits.conf for the user is reached. Red Hat Linux 7.2) How can I code this? This is probably a basic Java question but how do I reference to the top level ThreadGroup? With this code ThreadGroup tg = Thread.currentThread().getThreadGroup() ; while ( tg.getParent() != null) tg = tg.getParent() ; /* walk hierachy from tg */ would the code encounter problems with security manager restrictions when methods are invoked on the root object? In addition to the actual code to walk the Thread tree does anyone have a suggestion as to which classloader I should put the code in? Does it matter? Many Thanks for any suggestions, Janek __ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: How to list all Threads in the JVM? (Includes suggestion.)
use an application like optimizeIt or JProbe to profile the thread usage. Warning though, don't try running it on a system with less than 128mb of ram. peter Janek Bogucki wrote: Hi, We are trying to monitor the set of Threads in the JVM running Tomcat in order to fix a resource exhaustion problem we have. (Tomcat and/or our code is increasing the number of threads until the hard nproc limit in /etc/security/limits.conf for the user is reached. Red Hat Linux 7.2) How can I code this? This is probably a basic Java question but how do I reference to the top level ThreadGroup? With this code ThreadGroup tg = Thread.currentThread().getThreadGroup() ; while ( tg.getParent() != null) tg = tg.getParent() ; /* walk hierachy from tg */ would the code encounter problems with security manager restrictions when methods are invoked on the root object? In addition to the actual code to walk the Thread tree does anyone have a suggestion as to which classloader I should put the code in? Does it matter? Many Thanks for any suggestions, Janek __ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: How to list all Threads in the JVM? (Includes suggestion.)
--- peter lin [EMAIL PROTECTED] wrote: use an application like optimizeIt or JProbe to profile the thread usage. Warning though, don't try running it on a system with less than 128mb of ram. peter Thanks for the links: http://www.sitraka.com/software/jprobe/ http://www.borland.com/optimizeit/ It's not really what I need right now. If I had a simple class that formed the basis of a Thread which periodically dumped a list of all Threads in the JVM I'd be satified (for now...JProbe Threadalyzer looks very useful!). Thanks, Janek __ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
RE: How to list all Threads in the JVM? (Includes suggestion.)
Howdy, Your basic code snippet worked relatively well. In fact, I liked it enough to start using it, with a few modifications and enhancements. I'm attaching a more fully developed class to do some more, e.g. get a list of all threads, etc. You WILL get security (e.g. ThreadIllegalStateException) exceptions if you try to modify thread groups outside your own. For kicks, try the destroyRootThreadGroup() method in the attached class. ;) Yoav Shapira Millennium ChemInformatics -Original Message- From: Janek Bogucki [mailto:[EMAIL PROTECTED]] Sent: Wednesday, June 05, 2002 9:05 AM To: [EMAIL PROTECTED] Subject: How to list all Threads in the JVM? (Includes suggestion.) Hi, We are trying to monitor the set of Threads in the JVM running Tomcat in order to fix a resource exhaustion problem we have. (Tomcat and/or our code is increasing the number of threads until the hard nproc limit in /etc/security/limits.conf for the user is reached. Red Hat Linux 7.2) How can I code this? This is probably a basic Java question but how do I reference to the top level ThreadGroup? With this code ThreadGroup tg = Thread.currentThread().getThreadGroup() ; while ( tg.getParent() != null) tg = tg.getParent() ; /* walk hierachy from tg */ would the code encounter problems with security manager restrictions when methods are invoked on the root object? In addition to the actual code to walk the Thread tree does anyone have a suggestion as to which classloader I should put the code in? Does it matter? Many Thanks for any suggestions, Janek __ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- To unsubscribe, e-mail: mailto:tomcat-user- [EMAIL PROTECTED] For additional commands, e-mail: mailto:tomcat-user- [EMAIL PROTECTED] SystemThreadList.java Description: SystemThreadList.java -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: How to list all Threads in the JVM? (Includes suggestion.)
PLEASE REMOVE ME FROM YOUR MAILING LIST. I DO NOT KNOW WHO YOU ARE. THANK YOU... - Original Message - From: Shapira, Yoav [EMAIL PROTECTED] To: Tomcat Users List [EMAIL PROTECTED] Sent: Wednesday, June 05, 2002 9:29 AM Subject: RE: How to list all Threads in the JVM? (Includes suggestion.) Howdy, Your basic code snippet worked relatively well. In fact, I liked it enough to start using it, with a few modifications and enhancements. I'm attaching a more fully developed class to do some more, e.g. get a list of all threads, etc. You WILL get security (e.g. ThreadIllegalStateException) exceptions if you try to modify thread groups outside your own. For kicks, try the destroyRootThreadGroup() method in the attached class. ;) Yoav Shapira Millennium ChemInformatics -Original Message- From: Janek Bogucki [mailto:[EMAIL PROTECTED]] Sent: Wednesday, June 05, 2002 9:05 AM To: [EMAIL PROTECTED] Subject: How to list all Threads in the JVM? (Includes suggestion.) Hi, We are trying to monitor the set of Threads in the JVM running Tomcat in order to fix a resource exhaustion problem we have. (Tomcat and/or our code is increasing the number of threads until the hard nproc limit in /etc/security/limits.conf for the user is reached. Red Hat Linux 7.2) How can I code this? This is probably a basic Java question but how do I reference to the top level ThreadGroup? With this code ThreadGroup tg = Thread.currentThread().getThreadGroup() ; while ( tg.getParent() != null) tg = tg.getParent() ; /* walk hierachy from tg */ would the code encounter problems with security manager restrictions when methods are invoked on the root object? In addition to the actual code to walk the Thread tree does anyone have a suggestion as to which classloader I should put the code in? Does it matter? Many Thanks for any suggestions, Janek __ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- To unsubscribe, e-mail: mailto:tomcat-user- [EMAIL PROTECTED] For additional commands, e-mail: mailto:tomcat-user- [EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: How to list all Threads in the JVM? (Includes suggestion.)
PLEASE REMOVE ME FROM YOUR MAILING LIST. I DO NOT KNOW WHO YOU ARE. THANK YOU... - Original Message - From: Janek Bogucki [EMAIL PROTECTED] To: Tomcat Users List [EMAIL PROTECTED] Sent: Wednesday, June 05, 2002 8:21 AM Subject: Re: How to list all Threads in the JVM? (Includes suggestion.) --- peter lin [EMAIL PROTECTED] wrote: use an application like optimizeIt or JProbe to profile the thread usage. Warning though, don't try running it on a system with less than 128mb of ram. peter Thanks for the links: http://www.sitraka.com/software/jprobe/ http://www.borland.com/optimizeit/ It's not really what I need right now. If I had a simple class that formed the basis of a Thread which periodically dumped a list of all Threads in the JVM I'd be satified (for now...JProbe Threadalyzer looks very useful!). Thanks, Janek __ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
RE: How to list all Threads in the JVM? (Includes suggestion.)
Hi Yoav,
--- Shapira, Yoav [EMAIL PROTECTED] wrote: Howdy,
Your basic code snippet worked relatively well. In fact, I liked it
enough to start using it, with a few modifications and enhancements.
I'm attaching a more fully developed class to do some more, e.g. get a
list of all threads, etc.
You WILL get security (e.g. ThreadIllegalStateException) exceptions if
you try to modify thread groups outside your own. For kicks, try the
destroyRootThreadGroup() method in the attached class. ;)
Yoav Shapira
Millennium ChemInformatics
Thanks for posting the class, it was really good. (If anyone is having trouble with
Exercise 10.9
in The Java Programming Language Third Edition I reccommend a look at Yoav's class!).
I've integrated it in the web app. This is what I get shortly after starting Tomcat.
It's a good
starting point.
Many Thanks,
Janek
[SystemThreadList:
ThreadGroup 0= java.lang.ThreadGroup[name=main,maxpri=10], activeCount = 46
ThreadGroup 1= java.lang.ThreadGroup[name=system,maxpri=10], activeCount = 50
totalActiveCount = 96
(End of SystemThreadList)]Thread 0 = Thread[Reference Handler,10,system]
Thread 1 = Thread[Finalizer,8,system]
Thread 2 = Thread[Signal Dispatcher,10,system]
Thread 3 = Thread[CompileThread0,10,system]
Thread 4 = Thread[main,5,main]
Thread 5 = Thread[Thread-0,5,main]
Thread 6 = Thread[Thread-1,5,main]
Thread 7 = Thread[StandardManager[],5,main]
Thread 8 = Thread[Thread-2,5,main]
Thread 9 = Thread[Thread-3,5,main]
Thread 10 = Thread[Thread-4,5,main]
Thread 11 = Thread[Thread-5,5,main]
Thread 12 = Thread[Thread-6,5,main]
Thread 13 = Thread[Thread-7,5,main]
Thread 14 = Thread[Thread-8,5,main]
Thread 15 = Thread[Thread-9,5,main]
Thread 16 = Thread[Thread-10,5,main]
Thread 17 = Thread[Thread-11,5,main]
Thread 18 = Thread[Thread-12,5,main]
Thread 19 = Thread[Thread-13,5,main]
Thread 20 = Thread[Thread-14,5,main]
Thread 21 = Thread[Thread-15,5,main]
Thread 22 = Thread[Thread-16,5,main]
Thread 23 = Thread[Thread-17,5,main]
Thread 24 = Thread[Thread-18,5,main]
Thread 25 = Thread[Thread-19,5,main]
Thread 26 = Thread[Thread-20,5,main]
Thread 27 = Thread[Thread-21,5,main]
Thread 28 = Thread[StandardManager[],5,main]
Thread 29 = Thread[Thread-22,5,main]
Thread 30 = Thread[Thread-23,5,main]
Thread 31 = Thread[Thread-24,5,main]
Thread 32 = Thread[Thread-25,5,main]
Thread 33 = Thread[Thread-26,5,main]
Thread 34 = Thread[Thread-27,5,main]
Thread 35 = Thread[Thread-28,5,main]
Thread 36 = Thread[Thread-30,5,main]
Thread 37 = Thread[Thread-31,5,main]
Thread 38 = Thread[StandardManager[],5,main]
Thread 39 = Thread[Thread-32,5,main]
Thread 40 = Thread[Thread-33,5,main]
Thread 41 = Thread[Thread-34,5,main]
Thread 42 = Thread[Thread-35,5,main]
Thread 43 = Thread[Thread-37,5,main]
Thread 44 = Thread[Thread-38,5,main]
Thread 45 = Thread[Thread-39,5,main]
Thread 46 = Thread[Thread-40,5,main]
Thread 47 = Thread[Thread-41,5,main]
Thread 48 = Thread[Thread-42,5,main]
Thread 49 = Thread[Thread-43,5,main]
To dump this into a page, use this abbreviated version of SystemThreadList.main.
xxx () {
SystemThreadList stl = new SystemThreadList() ;
Thread[] allThreads = stl.getAllThreads();
if((allThreads == null) || (allThreads.length 1))
return SystemThreadListSAO: allThreads is null or length 1.;
StringBuffer sb = new StringBuffer(stl.toString() );
sb.append ( \n ) ;
// Individual thread info
Thread t = null;
for(int i = 0; i allThreads.length; i++) {
t = allThreads[i];
sb.append(Thread + i + = + t.toString());
sb.append ( \n ) ;
}
return sb.toString() ;
}
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