Tomcat hprof empty file

[Jason Polites <ja...@gmail.com>]

Hi all,

I am running Tomcat 5.5.23 on a Win32 platform as an NT Service, with the
native DLL.

I am experiencing the CPU spinning at 100% in our production environment,
which is not something I have seen in our dev or staging env.  In order to
determine the problem area, I have tried running Tomcat with hprof using the
following JVM option:

-Xrunhprof:cpu=samples,thread=y

I am setting this in the Java options tab of the Windows service dialog.  I
get a java.hprof.txt file created in the root tomcat directory, but there is
nothing in it other than the standard intro text.

This works when I run tomcat locally within eclipse (same tomcat version);
but when running in production I get no data!

This is really frustrating as I can't fix the CPU problem because I can't
identify it.

Help!

Thanks.

Re: Tomcat hprof empty file

[Jason Polites <ja...@gmail.com>]

I think I "may" have found the cause of the problem with HPROF.  A
CTRL+BREAK (on win32) is what triggers the dump of the hprof data to a text
file, but when running Tomcat as a win32 service it automatically sets the
-Xrs JVM option which causes the JVM to ignore these signals from the OS
(this is required to prevent Tomcat from dying when the console user logs
off.. which triggers a CTRL+C from Windows).

That, plus this obscure
reference<http://docs.sun.com/app/docs/doc/819-2634/6n4tl5koa?a=view>which
states:

"Do not use the -Xrs flag."

But does not really explain why.

So if I assume the hprof data is not being dumped because of the -Xrs
command, then I need to run Tomcat without this.  Of course this creates a
serious problem for me as I need it to run for a while so I get accurate
telemetry, and of course I can't log off the console otherwise the process
will die, but I am using remote desktop which will automatically log me off
after a timeout.

Might try vnc

Anyone got any other bright ideas?


On 5/8/07, Filip Hanik - Dev Lists <de...@hanik.com> wrote:
>
> maybe try to run it under another service manager, like the Java Service
> Wrapper
> http://people.apache.org/~fhanik/wrapper.html
>
> to rule out the case, that its a win service problem
> Filip
>
> Jason Polites wrote:
> > Hi all,
> >
> > I am running Tomcat 5.5.23 on a Win32 platform as an NT Service, with
> the
> > native DLL.
> >
> > I am experiencing the CPU spinning at 100% in our production
> environment,
> > which is not something I have seen in our dev or staging env.  In
> > order to
> > determine the problem area, I have tried running Tomcat with hprof
> > using the
> > following JVM option:
> >
> > -Xrunhprof:cpu=samples,thread=y
> >
> > I am setting this in the Java options tab of the Windows service
> > dialog.  I
> > get a java.hprof.txt file created in the root tomcat directory, but
> > there is
> > nothing in it other than the standard intro text.
> >
> > This works when I run tomcat locally within eclipse (same tomcat
> > version);
> > but when running in production I get no data!
> >
> > This is really frustrating as I can't fix the CPU problem because I
> can't
> > identify it.
> >
> > Help!
> >
> > Thanks.
> >
> > ------------------------------------------------------------------------
> >
> > No virus found in this incoming message.
> > Checked by AVG Free Edition.
> > Version: 7.5.467 / Virus Database: 269.6.2/787 - Release Date: 5/3/2007
> 2:11 PM
> >
>
>
> ---------------------------------------------------------------------
> To start a new topic, e-mail: users@tomcat.apache.org
> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
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>

Re: Tomcat hprof empty file

[Filip Hanik - Dev Lists <de...@hanik.com>]

maybe try to run it under another service manager, like the Java Service 
Wrapper
http://people.apache.org/~fhanik/wrapper.html

to rule out the case, that its a win service problem
Filip

Jason Polites wrote:
> Hi all,
>
> I am running Tomcat 5.5.23 on a Win32 platform as an NT Service, with the
> native DLL.
>
> I am experiencing the CPU spinning at 100% in our production environment,
> which is not something I have seen in our dev or staging env.  In 
> order to
> determine the problem area, I have tried running Tomcat with hprof 
> using the
> following JVM option:
>
> -Xrunhprof:cpu=samples,thread=y
>
> I am setting this in the Java options tab of the Windows service 
> dialog.  I
> get a java.hprof.txt file created in the root tomcat directory, but 
> there is
> nothing in it other than the standard intro text.
>
> This works when I run tomcat locally within eclipse (same tomcat 
> version);
> but when running in production I get no data!
>
> This is really frustrating as I can't fix the CPU problem because I can't
> identify it.
>
> Help!
>
> Thanks.
>
> ------------------------------------------------------------------------
>
> No virus found in this incoming message.
> Checked by AVG Free Edition. 
> Version: 7.5.467 / Virus Database: 269.6.2/787 - Release Date: 5/3/2007 2:11 PM
>   


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