Restrictions on the use of Fast Response Cache Accelerator
Note: The Fast Response Cache Accelerator is also know as the Cache Accelerator.
Caching:
- Pages with dynamic content (e.g. SSI, CGI, Java) are not cached.
- Default welcome pages are not cached. In other words, GET requests ending in / cannot be served out of the cache.
- Access-protected documents, and pages requested over SSL are not cached.
- Cache Accelerator supports only limited multi-language content negotiation. Only a single language version will be cached where a given URL maps to multiple translated versions.
- Cache Accelerator listens on all IP adapters of a the server, on the port specified by the Port directive.
It cannot be made to listen on some IP adapters but not others.
Only Valid on Windows NT:
- Files larger than 64KB are not cached.
- Cache Accelerator does not cache files on or log to locally mounted remote file systems (DFS, NFS, and so on).
- IP-based Virtual Host caching is not supported. The Cache Accelerator should be disabled for those directories.
You should use the "AfpaCache off" directive in any IP-based Virtual Host definitions.
- Name based Virtual Hosts are supported
Operational:
- Currently IBM HTTP Server Cache Accelerator does not run as a Proxy Server.
- Expires headers are not returned on cached responses.
- Cache Accelerator access log is not integrated into the HTTP Server access log.
Only Valid on Windows NT:
- If you enable the Cache Accelerator, set the MaxRequestPerChild directive to 0 to work around a problem that occurs when the child process is killed and restarted on a loaded web server.
- Only one instance of the server can be active at once, when running the Cache Accelerator.
- IBM HTTP Server should not be installed on a machine that is running IBM Netfinity Web Server Accelerator.
- There are no facilities for monitoring the Cache Accelerator (number or names of the files cached, for example) other than access logging.