The replication purge delay specifies the period after which the directory server purges changes on the replication server database. Any change that is older than the purge delay is removed from the replication server database regardless of whether the change has been applied.
Currently, the PingDirectory Server sets the default purge delay to one day. Administrators can change the default purge delay using the dsconfig tool. To ensure proper replication processing, you must have the same purge delay value set for all replication servers in the topology.