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From Nacho <>
Subject RE: Why tomcat NT service get killed when the user log off
Date Sun, 19 Nov 2000 05:52:21 GMT
Brett can you contributeyour solution to this problem tojakarta?? 

or at least send me thesources or binaries :-) is the better  more
elegant solution to this problem i've seen, 

if you can contribute this i'll be glad to commit it to tomcat 3.3 and

of course giving you credits as the rules mandate ;-)

Saludos ,
Ignacio J. Ortega

-----Mensaje original-----
De: Brett Bergquist []
Enviado el: jueves 16 de noviembre de 2000 1:01
Asunto: RE: Why tomcat NT service get killed when the user log off

Zhiping, even though jk_nt_service is being used to launch Tomcat, there
is a bug in the Java 1.3 runtime under Windows that causes any java.exe
process to be terminated when the user logs off. The bug is that a
console control handler is setup inside of the java runtime that detects
the CTRL_LOGOFF_EVENT that is sent by Windows to each process when the
user logs off and the handler inside of Java 1.3 is terminating the
process when this occurs. This is the correct operation for a normal
application running but not the correct one for a service.

There is a couple of packages around, one being located at another at that handle the CTRL_LOGOFF_EVENT. I tried
a couple of these and while I found that they indeed to stop the
application from being terminated by the CTRL_LOGOFF_EVENT, I found that
they interferred with the normal shutdown of Tomcat. That is, using
these packages, I was not able to shutdown Tomcat cleanly, which caused
the servlets to not have their "destroy" method invoked. 

The reason that this occurs is because the way that these packages work
is that they invoke the Java VM using the JNI interface. When Tomcat is
to be shutdown, the same JNI interface is used to invoke a shutdown
method. The problem occurs because the way that Tomcat (3.x) is shutdown
is by using the APJ interface to send the existing Tomcat instance a APJ
shutdown message (through a TCP connection in fact). These packages send
the APJ message using the JNI interface, but when call returns, they
assume that Tomcat is ready to be shutdown and they then tear down the
Java VM running the Tomcat process. In reality, the Tomcat process has
not yet received the APJ message through its socket interface and as
such has not shutdown cleanly and does not give the servlets a chance to
have their "destroy" method called.

Because my application needs to have the servlet's "destroy" method
called when Tomcat shuts down, I solved this problem by using the source
to "java.exe" launcher as a starting point and then modified it to
install a console control handler that ignores the CTRL_LOGOFF_EVENT. I
called this new launcher "javaex.exe". I then used jk_nt_service and
changed the configuration file references of "java.exe" to "javaex.exe".

I hope this helps.

-----Original Message-----
From: Zhiping Wei []
Sent: Wednesday, November 15, 2000 5:38 PM
To: ''
Subject: Why tomcat NT service get killed when the user log off

Please Help!!! 
This is for tomcat 3.2 beta 7 on Windows NT/2000. Tomcat is registed as
an NT service using 'jk_nt_service.exe' (under Systemlocal account).
It's starts fine but if I log off the windows, tomcat get killed which
is not suppose to be. Could anybody tell me why this happen and how to
fix it. 
-- Zhiping (ext: 307) 

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