Configure Fast Response Cache Accelerator cache size through a distributed platforms Web server


In the default IBM HTTP Server for distributed platforms configuration, the maximum Fast Cache Accelerator dynamic cache size is calculated as 1/8 of physical pin-able memory. On a machine with 384 megabytes of RAM, it allows a maximum of approximately 50 megabytes for the Fast Cache Accelerator dynamic cache. When this limit is reached, the Cache Accelerator then deletes older entries to cache new ones.

To configure the Cache Accelerator using the IBM HTTP Server for distributed platforms' AfpaDynaCacheMax directive, tune the maximum allowed cache size:

  1. Place the directive in the global server configuration scope, along with the other default Fast Cache Accelerator directives.

  2. Enable Fast Cache Accelerator.To enable the Fast Cache Accelerator, update the following directives in this IBM HTTP Server's http.conf file

    AfpaCache on
    AfpaLogFile "c:/Program Files/IBM HTTP Server/logs/afpalog" V-ECLF
    AfpaDynaCacheMax 10

    These above settings limit the dynamic cache size to 10 megabytes. If you use these directives to increase cache size, do not make the cache so large that all the physical memory is consumed. Determine how much memory is available when all applications are running, by using the Windows Task Manager.

    Assign no more than 50% of available physical memory to the dynamic cache. Specifying too large a cache not only decreases the performance of other applications, but also puts you at a risk for completely running out of memory.

    The default configuration does not include the AfpaDynaCacheMax directive where the cache size is automatically calculated as 1/8 of physical memory.


See Also

Configuring high-speed external caching through the Web server