Tomcat service crashes "unexpectedly", no trace in logs

[David Vandaele <Da...@dolmen.be>]

Hi,

We're experiencing Tomcat crashes during stresstesting of a webapplication. 

Situation: Tomcat runs as a Windows service.  During stresstests the Tomcat-services suddenly ends "unexpectedly".  The Windows eventlog logs states something like: "...service ended unexpectedly..."  The problem is not easily or consistently reproducable...

When I look at all the logs of Tomcat and of our webapplication, no mention of an exception or error or crash whatsoever !(?)  (They all just stop abruptly)

First I thought it was an OutOfMemoryError problem.  I forced an OutOfMemoryError myself by limiting the memory of the JVM of Tomcat severely.  But then I could see loggings of an OutOfMemoryError in the Tomcat stderr-log, which is not what I expected because I didn't expect any loggings of a crash at all...

The problem only *seems* to occur when the servermachine is completely left alone (not logged in or locked)  Additionally, it usually occurs after between 30-70 minutes or so.  When I keep monitoring the machine while the same tests are running the crash doesn't seem to occur ?!  Could it be a power-saving issue, like e.g. with the network-adaptor ?  Then I would not expect a crash, but a stacktrace ?

I tried adding a try-catch(Throwable) around a method where everything starts (the process method of my Struts ActionServlet). I've been trying to reproduce the problem since, but as I mentioned, it's not consistently reproducable...

I've searched the net trying to find related problems, or a JVM problem of some kind with this version, haven't been successful though...  If it is a problem with bad memory, I would expect to see different behaviour, like more random crashes, not only of the Tomcat service... 

Environment: Tomcat 4.1.29, JDK 1.4.2_03, Windows 2000ProSP4, bi-processor Xeon machine.

Any help/advice/ideas is really welcome and appreciated !

Kind regards,

David

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Re: Tomcat service crashes "unexpectedly", no trace in logs

[Greg Lappen <gr...@lapcominc.com>]

David,

I have been chasing a similar problem for weeks now with tomcat 5.0.28 
on Linux.  It occurs sporadically, sometimes a couple times a day, 
sometimes after weeks.  I see no errors in the log file and no core 
dumps.  At first I thought it was the JVM crashing but I've tracked it 
down to the JVM shutting down normally somehow, as if somewhere 
System.exit was being called.  I put a security policy in place and 
enabled the security manager to prevent the System.exit call so I 
should find the culprit in my log files the next time its called.

To test if this is what's happening, add a shutdownHook when your app 
starts like this:

public class ExitListener implements ServletContextListener {

     public void contextInitialized(ServletContextEvent event) {
         Runtime.getRuntime().addShutdownHook(new ExitListenerThread());
         System.out.println("ExitListener installed shutdown hook");
     }

     public void contextDestroyed(ServletContextEvent event) {
         System.out.println("ExitListener.contextDestroyed()");
     }
}

public class ExitListenerThread extends Thread {
     public void run() {
         System.out.println("ExitListenerThread running!!!");
         System.out.println("current time is: " + new java.util.Date());
     }
}

Hope this helps.

Greg
On Jan 14, 2005, at 2:04 PM, David Vandaele wrote:

> Hi,
>
> We're experiencing Tomcat crashes during stresstesting of a 
> webapplication.
>
> Situation: Tomcat runs as a Windows service.  During stresstests the 
> Tomcat-services suddenly ends "unexpectedly".  The Windows eventlog 
> logs states something like: "...service ended unexpectedly..."  The 
> problem is not easily or consistently reproducable...
>
> When I look at all the logs of Tomcat and of our webapplication, no 
> mention of an exception or error or crash whatsoever !(?)  (They all 
> just stop abruptly)
>
> First I thought it was an OutOfMemoryError problem.  I forced an 
> OutOfMemoryError myself by limiting the memory of the JVM of Tomcat 
> severely.  But then I could see loggings of an OutOfMemoryError in the 
> Tomcat stderr-log, which is not what I expected because I didn't 
> expect any loggings of a crash at all...
>
> The problem only *seems* to occur when the servermachine is completely 
> left alone (not logged in or locked)  Additionally, it usually occurs 
> after between 30-70 minutes or so.  When I keep monitoring the machine 
> while the same tests are running the crash doesn't seem to occur ?!  
> Could it be a power-saving issue, like e.g. with the network-adaptor ? 
>  Then I would not expect a crash, but a stacktrace ?
>
> I tried adding a try-catch(Throwable) around a method where everything 
> starts (the process method of my Struts ActionServlet). I've been 
> trying to reproduce the problem since, but as I mentioned, it's not 
> consistently reproducable...
>
> I've searched the net trying to find related problems, or a JVM 
> problem of some kind with this version, haven't been successful 
> though...  If it is a problem with bad memory, I would expect to see 
> different behaviour, like more random crashes, not only of the Tomcat 
> service...
>
> Environment: Tomcat 4.1.29, JDK 1.4.2_03, Windows 2000ProSP4, 
> bi-processor Xeon machine.
>
> Any help/advice/ideas is really welcome and appreciated !
>
> Kind regards,
>
> David
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
>
>
>


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