Few Useful Tips on Sun LDAP Multi-Master Replication

If you are using Sun Directory Server 5.2, here are few useful tips on Multi Master replications.

(1) The typical steps of configuring multi-master (say M1 and M2 fro reference) is to define replication agreement on each of the LDAP which push changes to other. But initially both the LDAPs has to be in sync. While defining the agreement from console, it usually displays a message that "remote replica of the selected agreement has not been initialized from this replica". The same message will be seen on other LDAP's console's agreement definition screen. This gives an impression as if both the LDAP has to be initialized with each other to be in perfect synchronization to start with. But NEVER do initialize both way.

For example, After defining replication agreement on each of the LDAP, only do a full initialization from M1 to M2. Never do the same from M2, even if agreement in M2 console displays the above said message of "remote replica of the selected agreement has not been initialized from this replica".

(2) While doing full initialization from M1 to M2, the schema MAY NOT not get loaded to M2. So copy ".../slapd-M2/config/schema" directory from M1 to M2 followed by restarting M2. Do the initialization after the schema at both M1 and M2 are same.

(3) Index information does not get loaded to when an initialization is done from one master to other. So export the index from source master and import it to other master followed by a re-indexing.

(4) For some reason, if you have to delete the existing agreement and create the same again, make sure you are assigning a new replica-id. This will avoid possible data corruption.

(5) When exporting data from any of the LDAPs participating in multi-master replication, you will see replication info(e.g. obEnabled;vucsn-49de55e5000000010000;deleted: disabled) in exported data. what if you wanted clean data only? There are many ways, here is one of them.

ldapsearch.exe -h yourHost -p yourPort -D myUser -w myPassword -b obname=o=Finance,dc=company,dc=com -s sub (objectclass=Top) > exported.ldif