Replication is based on an eventual-consistency model, where updates that are propagated through a connected network of servers will eventually be consistent on all servers over a very short period of time. In a typical update operation, a client application updates an entry or group of entries on the PingDirectory Server with an ADD, DELETE, MODIFY, or MODIFY DN operation. After processing the operation, the Directory Server returns an LDAP response, while concurrently propagating the update to the other servers in the replicated topology. This concurrent processing model allows the client to continue submitting update requests without waiting for a replication completion response from the server. Alternatively, assured replication can be configured for specific write requests that requires local or global consistency, across datacenter locations, before a response is returned to the client. For more information, see Configuring assured replication.
To support this processing model, replication never locks the targeted entries at the other Directory Server instances before an update can be made locally. This means that the replicated Directory Servers may have an inconsistent view of the targeted entry for a very short period of time but will catch up as the propagated changes are applied. The eventual-consistency model also allows clients to complete update operations faster, since clients do not have to wait for replication to propagate the change. The rate of update operations remains the same no matter how many Directory Servers participate in replication.