Service Crashing

[Cuong Tong]

I ran my service and it crashes everynow and then. The following log is recoreded
in the Application Event viewer

An unhandled win32 exception occurred in XYZService.exe [9204]. Just-In-Time
debugging this exception failed with the following error: Debugger could
not be started because no user is logged on.

Has anyone got any comments?

 

[Kerem Gümrükcü]

Hi,

Has anyone got any comments?

Yes,...

Try to debug your service or wrap critical code segments
into a try-catch block and try to find out what makes this
that bad. See here for some VB Example (not different from
C#)

http://www.ondotnet.com/pub/a/dotnet/2003/09/02/debuggingsvcs.html

You also can post some code here, so that we can
have a look at your code,...

I could not find some error code on my system with "9204".
You can try, maybe you will have that code. Check out
my little Exception Viewer if you like:
http://entwicklung.junetz.de/projects/opensource/WindowsExceptionViewer/WindowsExceptionViewer.zip

But best would be some code here,...


Regards

Kerem


--

 

[Marc Gravell]

...or wrap critical code segments into a try-catch block...

Just to observe that the most pragmatic approach here may actually be
to wrap your main work method[*] in a try/catch, doing some error-
logging in the "catch" (perhaps simply writing the message,
stacktrace, etc to the event-log). I agree that exception handling
(esp. "finally") should be "where necessary" in the code, but this
isn't often a useful debugging tool unless you get lucky.

[*]=since tihs is a service, I'm assuming that you spin up a thread in
the "start"; I mean the method you used for the delegate to start the
thread.

Marc

 

[Marc Gravell]

Oh - and any other thread you start ;-p

Any thread that exits because of an unhandled exception will break
your app; this is a good thing as it almost certainly indicates
instability. If you are using lots of threading, perhaps add your
error-logging method to AppDomain.UnhandledException (noting that
ExceptionObject will almost certainly be an Exception).

A very crude (and untested) implementation is shown below. Note that
you might need your installer to create the named ("MyService") event-
source, otherwise this could iteslf explode.

AppDomain.CurrentDomain.UnhandledException +=
CurrentDomain_UnhandledException;
....
static void CurrentDomain_UnhandledException(object sender,
UnhandledExceptionEventArgs e) {
Exception ex = e.ExceptionObject as Exception;
if (ex == null) {
string msg; // try to log whatever the heck happened!
try { msg = e.ExceptionObject.ToString(); }
catch { msg = "(unreadable exception)"; }
EventLog.WriteEntry("MyService", msg,
EventLogEntryType.Error);
} else {
// log outermost message and stack-trace
EventLog.WriteEntry("MyService", ex.Message,
EventLogEntryType.Error);
EventLog.WriteEntry("MyService", ex.StackTrace,
EventLogEntryType.Information);
while ((ex = ex.InnerException) != null) { // log
inner exception messages
EventLog.WriteEntry("MyService", ex.Message,
EventLogEntryType.Information);
}
}
}