Configure high-speed external caching through the Web server

IBM HTTP Server for iSeries (powered by Apache) contains a high speed cache, Fast Response Cache Accelerator (FRCA). WAS for iSeries fragment cache uses IBM HTTP Server for iSeries (powered by Apache) as an external cache with the appropriate configuration.

Note: FRCA is not available on Domino HTTP Server or those servers that run OS/400 V5R1 or earlier.

Perform the following steps to configure high-speed external caching:

  1. Install WAS and IBM HTTP Server for iSeries (powered by Apache).

  2. Configure the Fast Response Cache Accelerator on the Web server.

    1. Open the following URL in a Web browser: 

      http://your.server.name:port

      where your.server.name is the name of your application server and port is your HTTP administration port number. The default value is 2001.

    2. Click IBM HTTP Server for iSeries.
    3. In the Server drop-down list, select the Web server you want to work with.
    4. In the navigation bar, click FRCA.
    5. On the General Settings tab, select the radio button next to the appropriate port.
    6. Specify applicable settings, and select Enabled from the drop-down list in the FRCA field.
    7. Click Apply.

  3. Configure an external cache group on the application server. Use the following parameters:

    • External cache group: afpa.
    • AdapterBean name: com.ibm.servlet.dynacache.Afpa

  4. Enter the assigned port number from the Web server console.

  5. Configure a cache policy using external cache.

After you configure FRCA, you can use external cache attribute when you build your cache policies.

Configure FRCA cache size through the Web server

In the default IBM HTTP Server for iSeries (powered by Apache) configuration, the maximum FRCA dynamic cache size is calculated as 1/8 of physical pin-able memory. For example, on a machine with 384MB of RAM, it allows a maximum of approximately 50MB for FRCA's dynamic cache. When this limit is reached, FRCA deletes older entries using a Least Recently Used (LRU) algorithm to cache new ones.

Perform the following steps to configure a maximum cache size in FRCA:

  1. Open the following URL in a Web browser: 

    http://your.server.name:port

    where your.server.name is the name of your application server and port is your HTTP administration port number. The default value is 2001.

  2. Click IBM HTTP Server for iSeries.
  3. In the Server drop-down list, select the Web server you want to work with.
  4. In the navigation bar, click FRCA.
  5. On the FRCA File Cache tab, select Enabled from the FRCA file cache capabilities field.
  6. Specify your maximum cache size and maximum file cache size values.
  7. Click Apply.
  8. Restart the IBM HTTP Server for iSeries server.

If you increase cache size, assign no more than 50% of available physical memory to the 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. Determine how much memory is available when all applications are running by using the Work with System Status (WRKSYSSTS) CL command on an OS/400 command line.