Introduction to LDAP Replication
Replication?
When an LDAP Directory Service is set up, it can have one, several, or or many servers responding to requests.
If more than one server is handling the load, changes made to any server have to be propagated to the others so each has a complete and up to date copy of the directory’s data. Propagating changes is called Replication.
Changes are requested by authorized LDAP Client programs or utility programs and are sent to one of the servers. How it gets there is a longer discussion covered in the Introduction to Routing Requests to LDAP Serversnull. But wherever and however the request gets to a server, it processes it and sends the results (data or a result code) back.
But those changes need to be replicated to the rest of the servers. The the IETF standards specify that an LDAP implementation MUST provide replication of changes. OpenLDAP provides sophistication for replication.
The Idea
Requests for changes are normally routed to one or more of the servers in the cluster.