1.

Switch over from primary to secondary data center

See Switching over from the primary to the secondary data center.

2.

Resolve the cause of the primary data center failure. Then apply the following processes to return it to being the primary.

3.

Reverse replication direction after switching from primary to secondary role

See Reversing data replication when the DC2 is the primary.

4.

Switch back from the secondary data center to the primary.

Use the same process as previous used for switching but with the data centers reversed.

See Switching over from the primary to the secondary data center.