[[PageOutline(2-5,Contents,pullout)]]

= Cache Management

Because network connections are expensive in time, compute cycles and network bandwidth, a strong caching paradigm was implemented to help lower the use of resources and lower the response time. 

== Configuration

 - The timeout and size can be tweaked as needed to support a particular environment. The system will send out an INFO alert if it's purging too quickly.
 - The memory cache can be completely disabled by setting the size to 0. This should only be done if you are using a single process, as the database interface *should* be caching results.

== Lookups

 - Each search to the ActiveDirectory server is through a cached LDAP filehandle. The restart option has been enabled to allow it to persist. 
 - When valid data is found, the data is pickled, and the key hashed and stored in a new table in the database called `ad_cache`.
 - It's also stored in a class variable {{{_cache}}} which is a dictionary.

== Retrieval

 - The memory cache is checked first.
 - Then the database cache.
 - Lastly the AD server itself is searched.
 - Any results are then pushed back on the cache(s).

== Integration

 - Data is cached by 'class' where appropriate to speed up processing.
 - All ldap searches are cached using a key which is a hashed combination of `( base_dn, scope, filter )`.