Each data center or the cloud region hosts an independent cluster of its own.

Primary data center serves the traffic and is exposed to the client and you must turn on the secondary data center only when the primary data center goes down due to a disaster.

Before performing the failover process:

In cold standby mode:

You must install API Gateway in the secondary data center and ensure that the fix upgrades of the primary data center is applied to the secondary data center too.

You must run the backup scripts periodically to take a snapshot of data from the primary data store and store the snapshots in a suitable externalized storage like AWS S3, Azure Blobs.

In warm standby mode:

You must install API Gateway in the secondary data center and ensure that the fix upgrades of the primary data center is applied to the secondary data center too.

You must run the backup scripts periodically to take a snapshot of data from the primary data store and store the snapshots in a suitable externalized storage system.

You must run the restore scripts periodically to restore the backedup snapshots from the externalized storage in the secondary data center.

During the failover process:

In cold standby mode, you must start API Data Store, restore the data from the snapshots in API Data Store, and then start API Gateway in the secondary data center. This approach impacts the RTO (high), but is cost effective.

In warm standby mode, as API Data Store is always turned on and the data is already restored from the snapshots in API Data Store, you must just restart API Gateway alone. This approach reduces RTO, but the cost of this approach is higher compared to the cold-standby mode.

After completing the disaster recovery process, when you want to switch back the traffic from the secondary data center to primary data center, you can follow the failback process.