The LDAP data cache resolves the master/slave LDAP configuration problem by providing Calendar Server clients with the most recent LDAP data, even when the master directory server has not updated each slave directory server.
If the LDAP data cache is enabled, Calendar Server writes committed LDAP data to the cache database (ldapcache.db file). By default, the LDAP cache database is located in the ldap_cache database directory, but you can configure a different location if you prefer.
When a client makes a change to the LDAP data for a single user, Calendar Server writes the revised data to the LDAP cache database (as well as to the slave directory server). A subsequent client operation retrieves the LDAP data from the cache database.
This data retrieval applies to the following operations for a single user:
User's attributes at login
User's options (such as color scheme or time zone)
User's calendar groups
User's subscribed list of calendars
Thus, the LDAP data cache database provides for:
Data consistency across processes on a single system The database is available to all Calendar Server processes on a multiprocessor system.
Data persistence across user sessions The database is permanent and does not require refreshing.