Configuring servlet caching using wsadmin scripting

You can configure servlet caching with scripting and the wsadmin tool. The dynamic cache service works within an application server Java™ virtual machine (JVM), intercepting calls to cacheable objects. For example, it intercepts calls through a servlet service method or a command execute method, and either stores the output of the object to the cache or serves the content of the object from the dynamic cache.

Before you begin

Before you can configure servlet caching, you must configure dynamic cache. Use the configureDynamicCache Jython script in the AdminServerManagement script library to configure dynamic caching. The wsadmin tool automatically loads the script when the tool starts. Use the following syntax to configure dynamic caching using the configureDynamicCache script:

AdminServerManagement.configureDynamicCache(nodeName, serverName,
 defaultPriority,cacheSize, externalCacheGroupName,
 externalCacheGroupType, otherAttributeList)

For additional information and argument definitions, see the documentation for the AdminServerMananagment script library.

About this task

After a servlet is invoked and completes generating the output to cache, a cache entry is created containing the output and the side effects of the servlet. These side effects can include calls to other servlets or JavaServer Pages (JSP) files or metadata about the entry, including timeout and entry priority information. Configure servlet caching to save the output of servlets and JavaServer Pages (JSP) files to the dynamic cache.

Best practice: If you use the wsadmin tool to enable servlet caching, verify that portlet fragment caching is also enabled. Similarly, if you use the wsadmin tool to disable servlet caching, verify that portlet fragment caching is also disabled. The settings for these two caching functions must remain synchronized. If you enable or disable servlet caching using the administrative console, synchronization performed automatically.

To see a list of parameters associated with dynamic caching, use the attributes command. For example:

$AdminConfig attributes DynamicCache

Procedure

Start the wsadmin scripting tool.
Retrieve the configuration ID of the server object.
The following example sets the first server found to the s1 variable:
- Using Jacl:
```
set s1 [$AdminConfig getid /Server:server1/]
```
- Using Jython:
```
s1 = AdminConfig.getid('/Server:server1/')
```
Retrieve the web containers for the server of interest. and assign them to the wc variable.
The following example sets the web container to the wc variable:
- Using Jacl:
```
set wc [$AdminConfig list WebContainer $s1]
```
- Using Jython:
```
wc = AdminConfig.list('WebContainer', s1)
```
Set a variable with the new value for the enableServletCaching attribute.
Set the enableServletCaching attribute to true and assign it to the serEnable variable, as the following example demonstrates:
- Using Jacl:
```
set serEnable "{enableServletCaching true}"
```
- Using Jython:
```
serEnable = [['enableServletCaching', 'true']]
```
Enable dynamic caching.
Use the AdminConfig object to modify the application server configuration, as the following example demonstrates:
- Using Jacl:
```
$AdminConfig modify $wc $serEnable
```
- Using Jython:
```
AdminConfig.modify(wc, serEnable)
```