If Master 1 is not already stopped, stop it.
Identify the cause of the failure.
If the failure is easily repaired, by replacing a network cable, for example, make the repair and go to Step 3.
If the problem is more serious, the failure might take more time to fix.
Ensure that any applications that access Master 1 are redirected to point to Master 2 or Master 3, through Directory Proxy Server.
Check the availability of a recent backup.
If a recent backup is available, reinitialize Master 1 from the backup and go to Step 3.
If a recent backup is not available, do one of the following:
Restart Master 1 and perform a total initialization from Master 2 or from Master 3 to Master 1.
For details on this procedure, see Initializing Replicas in Oracle Fusion Middleware Administration Guide for Oracle Directory Server Enterprise Edition.
If performing a total initialization will take too long, perform an online export from Master 2, or Master 3, and an import to Master 1.
Start Master 1, if it is not already started.
If Master 1 is in read-only mode, set it to read/write mode.
Check that replication is functioning correctly.
You can use DSCC, dsccmon view-suffixes, or the insync command to check replication.