WebLogic: HTTP 404 errors for requests to /bea_wls_internal/WLDummyInitJVMIDs

Problem:

Several occurrences of the following seen in the WebLogic Server 9.2 MP2 access logs:

“HEAD /bea_wls_internal/WLDummyInitJVMIDs HTTP/1.0" 404 1214

Background & Analysis:

If the WebLogic proxy plugin is used in a Web Server to load balance requests across WebLogic servers in a  cluster, then the plugin sends a dummy request to the cluster in order to retrieve the cluster server list. The cluster server list is present in the HTTP Response Header and not in the body. So, it does not matter if a non-existent web application is requested. That’s why a request is made to a non-existent web application/context called /bea_wls_internal/WLDummyInitJVMIDs, thereby resulting in a HTTP 404 error, even though the objective of obtaining the cluster server list is achieved. Well, Oracle could have handled this functionality better by internally deploying a dummy application to prevent these HTTP 404 errors

Solution:

There are two solutions to get rid of the HTTP 404 errors:

SOLUTION 1: Configure a default web application which does nothing (dummy).

SOLUTION 2: Obtain patch CR271671 (for 9.2 MP2) from Oracle to suppress HTTP 404 errors in access logs if you do not wish to configure a default web application. If you’re using another version of WebLogic Server, request Oracle for a suitable patch similar to CR271671.

Root Cause:

/bea_wls_internal/WLDummyInitJVMIDs is a non-existent web application since the WebLogic proxy plugin obtains required information from HTTP Response Headers alone.

NOTE:
(1) The solution above describes a successful problem-solving experience and may not be applicable to other problems with similar symptoms.
(2) Your rating of this post will be much appreciated. Also, feel free to leave comments.