ServerCacheMode
Caching enables the system to store definitions locally on the application server, eliminating unnecessary trips to the database server. If caching were disabled, the system would need to retrieve definitions from the database with each request, every time. This adds significant overhead to each transaction and affects system response times.
If server caching is enabled on the application server, which is usually the recommended approach, there are two modes of caching from which to choose.
| Cache Mode | Description |
|---|---|
|
Non-shared cache |
By default, non-shared cache mode is enabled (ServerCacheMode set to 0). With the non-shared cache mode, each server process that starts within a domain maintains its own separate cache file. For example, assume you had two PSAPPSRV processes configured in a domain. In non-shared cache mode, there is one cache directory per PSAPPSRV server process, which each individual PSAPPSRV process uses separately. In this case, you can find the cache files in PS_CFG_HOME\appserv\domain\cache\PSAPPSRV_1 and \PSAPPSRV_2. While the cache directories will grow over time to include the most used definitions, you have the option to preload the non-shared cache directories with the most used system definitions. See Configuring an Application Server Domain to Preload Cache. |
|
Shared cache |
To set shared caching for the domain, enter 1 at the Set ServerCacheMode prompt. With this option enabled, you can find the cache files in PS_CFG_HOME\appserv\domain\cache\share. The system assumes that a preloaded cache exists in the share directory. The preloaded cache contains most instances of the managed object types that are cached to file. When you boot the application server, if shared cache files are enabled but no cache files exist in the expected location, the system reverts to unshared caching. To preload shared cache, you run delivered Application Engine programs that build your shared cache. |