The first step in getting ready to fail back processing to the primary computer is to begin replication from the secondary database to the primary database on the primary machine. This process is knows as secondary replication.

As shown in the following figure, setting up secondary replication begins with a backup of the secondary database. Using an online backup limits the amount of downtime required.

Figure 1. Performing an online backup of secondary database


The backup files must be either sent to the primary machine or stored on a shared device that both the primary and secondary machines can access.

Once the backup files are available on the primary machine, you can restore the new primary database using the files, as shown in the following figure.

Figure 2. Restoring backup of secondary database


Before you restore the database, ensure that you have set up a structure file that the PROREST utility can use. For details about creating a structure file, see Step 2: Create a structure file.

You must now transition the primary database from a source to a target, as shown in the following figure.

Figure 3. Transitioning source database to target


You can use either of the following methods to transition the primary database:

  • To transition the database as it is restored, use the following command: 
    prorest primary-db-namebackup-file -REPLTransition
  • To transition the database after it has been restored, first use the following command to restore it: 
    prorest primary-db-namebackup-file

    Then use the following command for transition:

    proutil primary-db-name -C enableSiteReplication target

Regardless of which method you choose, the primary database will become a target database ready to be the replica of the production database on the secondary machine.

At this point, the secondary database is a source database and the primary database is a target database, as shown in the following figure.

Figure 4. Transition completes


You can now perform secondary replication.