Configuring the cacheAgentService directive so that the cache agent runs successfully in a reverse proxy setup
 Technote (troubleshooting)
 
Problem(Abstract)
This technote provides setup information for the cache agent to work successfully using Caching Proxy in a reverse proxy configuration when the Proxy HTTP rule is disabled because of security concerns.
 
Cause
The cache agent always sends a fully qualified URI, with protocol and host name, to Caching Proxy when refreshing the cache for Caching Proxy.

For security reasons, when you use a reverse proxy configuration, you must disable the Proxy http:* rule in ibmproxy.conf. However, disabling this rule prevents the cache agent from successfully sending requests and refreshing the cache content of Caching Proxy.

 
Resolving the problem
Use the cacheAgentService directive, which is another internal service provided by Caching Proxy, to avoid this problem. To enable the service, put the following directive before any other mapping rules in the ibmproxy.conf file:
Service   /any-valid-string*  INTERNAL:cacheagentservice

The variable any-valid-string is any string that is valid and that does not conflict with other mapping rules in the ibmproxy.conf file.

Both Caching Proxy and cache agent parse the URI based on this service directive. Instead of sending the URI directly to Caching Proxy, the cache agent utility prepends the URI with the /any-valid-string pattern in the service directive.

For example, the cache agent transforms the URI http://www.ibm.com/ to /any-valid-string/http://www.ibm.com/

The cache agent sends the URI with the prefix to Caching Proxy. When Caching Proxy receives the request, it removes the prefix /any-valid-string/. If the remaining URI is a fully qualified unit, Caching Proxy directly serves the request without mapping the URI against other rules.

Additionally, the cache agent can send a relative URI to the Caching Proxy. For example, if you add LoadURL /abc/ using the previously referenced service directive in the ibmproxy.conf file, the cache agent transforms it into /any-valid-string/abc/ and sends it to Caching Proxy. Caching Proxy receives the URL, removes the prefix, maps /abc/ against other mapping rules, and handles the request if there is a match.
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Edge Component
Operating system(s): Windows
Software version: 6.0.2
Software edition:
Reference #: 1214771
IBM Group: Software Group
Modified date: Aug 19, 2005