A Master/Slave LDAP configuration includes a master (root) directory server and one or more slave (consumer or replica) directory servers. Calendar Server can access the master LDAP directory server either directly or through a slave directory server:
If Calendar Server accesses the master LDAP directory server directly, the LDAP should be accurate, and you do not need to configure the LDAP data cache. In this case, make sure that the local.ldap.cache.enable parameter is set to “no” (which is the default).
If Calendar Server accesses the master LDAP directory server through a slave directory server, LDAP data changes are usually written to the master directory server transparently using an LDAP referral, which in turn replicates the data back to each slave directory server. This introduces a delay in the availability of committed LDAP data. For example, Calendar Server commits an LDAP data change, but the new data is not available for a specific amount of time because of the delay in the master directory server updating each slave directory server. A subsequent Calendar Server client operation uses the old LDAP data and presents an out-of-date view.