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Posted to users@tomcat.apache.org by "Wm.A.Stafford" <st...@marine.rutgers.edu> on 2007/09/27 21:06:20 UTC
Tomcat hangs, what to do to diagnose the problem?
Our Tomcat 4.1.30 instance seems to hang about once a week. i.e. the
application is unresponsive and it can not be restarted from the
management console. Tomcat must be restarted to restore functionality.
There is nothing in the logs to indicate explicitly what is going on.
The only logging that may be diagnostic is what gets logged when we
attempt to restart the hung application.
2007-09-27 10:49:55 HTMLManager: restart: Reloading web application at
'/OWEB'
2007-09-27 10:49:55 StandardContext[/OWEB]: Reloading this Context has
started
2007-09-27 10:49:55 StandardWrapper[/OWEB:ControllerServlet]: Waiting
for 66 instance(s) to be deallocated
I'm not sure what this means but if there are 66 instances of the
applications controller servlet that could be a clue as to what is going
on. There should be only one.
This instance of Tomcat is running only our application. We did not see
this behavior with the previous release. We do not see the behavior on
any of the three development/test machines.
Along with a new release we moved from Java 1.4 to Java 5.0. The server
in question is running Linux.
Can anyone suggest diagnostics to tell what is going on?
Are there any known scenarios that result in this 'hung' behavior?
Thanks for any guidance,
-=bill
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Re: Tomcat hangs, what to do to diagnose the problem?
Posted by Filip Hanik - Dev Lists <de...@hanik.com>.
do "kill -3 <tomcat pid>"
that generates stack trace for each thread (aka thread dump) into
std.out, you might want to do it twice so that you can compare them dump
Filip
Wm.A.Stafford wrote:
> Our Tomcat 4.1.30 instance seems to hang about once a week. i.e. the
> application is unresponsive and it can not be restarted from the
> management console. Tomcat must be restarted to restore
> functionality. There is nothing in the logs to indicate explicitly
> what is going on. The only logging that may be diagnostic is what
> gets logged when we attempt to restart the hung application.
>
> 2007-09-27 10:49:55 HTMLManager: restart: Reloading web application at
> '/OWEB'
> 2007-09-27 10:49:55 StandardContext[/OWEB]: Reloading this Context has
> started
> 2007-09-27 10:49:55 StandardWrapper[/OWEB:ControllerServlet]: Waiting
> for 66 instance(s) to be deallocated
>
> I'm not sure what this means but if there are 66 instances of the
> applications controller servlet that could be a clue as to what is
> going on. There should be only one.
>
> This instance of Tomcat is running only our application. We did not
> see this behavior with the previous release. We do not see the
> behavior on any of the three development/test machines.
>
> Along with a new release we moved from Java 1.4 to Java 5.0. The
> server in question is running Linux.
> Can anyone suggest diagnostics to tell what is going on? Are there any
> known scenarios that result in this 'hung' behavior?
>
> Thanks for any guidance,
> -=bill
>
> ---------------------------------------------------------------------
> To start a new topic, e-mail: users@tomcat.apache.org
> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
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>
>
>
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RE: Tomcat hangs, what to do to diagnose the problem?
Posted by "Caldarale, Charles R" <Ch...@unisys.com>.
> From: foo shyn [mailto:fooshyn@optegra.com.my]
> Subject: Re: Tomcat hangs, what to do to diagnose the problem?
>
> just wonder is the JMX package bundled together with
> Tomcat 4.1 as well? or it's only available to Tomcat
> 5.0 onwards?
JMX (and therefore JConsole) is dependent on the JRE level, not Tomcat.
You need a 1.5 or later Sun JDK in order to use JConsole.
(Newer versions of Tomcat use JMX MBeans, but we're interested in the
ones internal to the JVM in order to examine heap consumption.)
- Chuck
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Re: Tomcat hangs, what to do to diagnose the problem?
Posted by Mark Thomas <ma...@apache.org>.
Please do not hi-jack threads.
Mark
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Re: Tomcat hangs, what to do to diagnose the problem?
Posted by foo shyn <fo...@optegra.com.my>.
Hi,
Sorry if i'd hijacked this thread, just wonder is the JMX package
bundled together with Tomcat 4.1 as well? or it's only available to
Tomcat 5.0 onwards?
Thanx
FooShyn
Caldarale, Charles R wrote:
>> From: Wm.A.Stafford [mailto:stafford@marine.rutgers.edu]
>> Subject: Tomcat hangs, what to do to diagnose the problem?
>>
>> Can anyone suggest diagnostics to tell what is going on?
>>
>
> Try the usual:
>
> 1) enable JMX monitoring (-Dcom.sun.management.jmxremote) and look at
> the JVM with JConsole, especially at the heap and PermGen usage
>
> 2) get a thread dump (kill -3) and see where everybody is stuck
>
> - Chuck
>
>
> THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY
> MATERIAL and is thus for use only by the intended recipient. If you
> received this in error, please contact the sender and delete the e-mail
> and its attachments from all computers.
>
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>
>
>
>
>
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RE: Tomcat hangs, what to do to diagnose the problem?
Posted by "Caldarale, Charles R" <Ch...@unisys.com>.
> From: Wm.A.Stafford [mailto:stafford@marine.rutgers.edu]
> Subject: Tomcat hangs, what to do to diagnose the problem?
>
> Can anyone suggest diagnostics to tell what is going on?
Try the usual:
1) enable JMX monitoring (-Dcom.sun.management.jmxremote) and look at
the JVM with JConsole, especially at the heap and PermGen usage
2) get a thread dump (kill -3) and see where everybody is stuck
- Chuck
THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY
MATERIAL and is thus for use only by the intended recipient. If you
received this in error, please contact the sender and delete the e-mail
and its attachments from all computers.
---------------------------------------------------------------------
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Re: Tomcat hangs, what to do to diagnose the problem?
Posted by Jim Cox <sh...@gmail.com>.
On 9/27/07, Wm.A.Stafford <st...@marine.rutgers.edu> wrote:
> Our Tomcat 4.1.30 instance seems to hang about once a week. i.e. the
> application is unresponsive and it can not be restarted from the
> management console. Tomcat must be restarted to restore functionality.
> There is nothing in the logs to indicate explicitly what is going on.
> The only logging that may be diagnostic is what gets logged when we
> attempt to restart the hung application.
>
> 2007-09-27 10:49:55 HTMLManager: restart: Reloading web application at
> '/OWEB'
> 2007-09-27 10:49:55 StandardContext[/OWEB]: Reloading this Context has
> started
> 2007-09-27 10:49:55 StandardWrapper[/OWEB:ControllerServlet]: Waiting
> for 66 instance(s) to be deallocated
>
> I'm not sure what this means but if there are 66 instances of the
> applications controller servlet that could be a clue as to what is going
> on. There should be only one.
>
> This instance of Tomcat is running only our application. We did not see
> this behavior with the previous release. We do not see the behavior on
> any of the three development/test machines.
>
> Along with a new release we moved from Java 1.4 to Java 5.0. The server
> in question is running Linux.
>
> Can anyone suggest diagnostics to tell what is going on?
> Are there any known scenarios that result in this 'hung' behavior?
>
> Thanks for any guidance,
> -=bill
>
> ---------------------------------------------------------------------
> To start a new topic, e-mail: users@tomcat.apache.org
> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
> For additional commands, e-mail: users-help@tomcat.apache.org
Does that version of Tomcat leak OS resources (e.g. file handles) when
reloading webapps (v. a server stop/start)?
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