Getting intermittent HTTP 500 errors on Windows Tomcat 5.5. What logs to check?

Question

I'm running an IVR application on Windows Tomcat 5.5, and I'm getting occasional HTTP 500 errors. For example, I'll make the same POST request 20 times, and get 20 correct results. The 21st time, however, it results in an HTTP 500 error.

The problem is that the "browser" in question is encapsulated in a telephony server, and I can't see the actual error that's displayed. I've checked logs for stdout, stderr, and catalina, and none of them show information on the error. The only indicator that a 500 has occurred on the server is in the localhost access log, and it doesn't offer any clues as to what happened.

Where else can I look to determine what's going on, here?

Thanks!
IVR Avenger

Answer 1

Do you have the ability to configure the logging levels on your Tomcat web application ? If so, and you bump up the logging to debug level, you should see the error info in catalina.out, since HTTP 500 indicates an error on the server side.

If you can't increase the logging levels, the next best thing I can think of is to use a tool that will show you the HTTP traffic going between the server and the client. It's usually easiest to use a browser plugin to do that, but since you can't do that you could try a network sniffing tool such as Ethereal.