How Do I Set Up Data Center in Warm Standby Mode?

This use case explains how to set up the data centers in warm standby mode to achieve disaster recovery.

For example, assume that you have two data centers DC 1 and DC 2 in the following landscape:

Data Center Name	Host Name	Region
DC 1	uk.myhost.com	United Kingdom
DC 2	us.myhost.com	United States

Here, the DC 1 is in active mode and DC 2 is passive, that is DC2 is up but the systems are in shutdown state.

Pre-requisites

You must install API Gateway in DC2 and ensure that the fix upgrades of DC1 is applied to DC2 too.

You must run the following backup script periodically to take a snapshot of data from DC1 and store the snapshots in a suitable externalized storage system based on the RPO. For example, you can use crontab command scheduler to back up the data for every 15 minutes using this command:

*/15 * * * * /APIM/SAG/apigatewayUtil.sh

You must run the following restore script periodically to restore the backup snapshots from the externalized storage in DC2.

apigatewayUtil.sh restore backup -name backup_file_name

For more information about backup and restore, see Data backup

Failover and Failback process

1. During the failover process:

Restart API Gateway in DC2.

As API Data Store is always turned on and the data is already restored from the snapshots in API Data Store, and API Gateway is already installed, you just have to restart API Gateway in DC 2. The downtime for this mode would be the time when you start API Gateway in DC 2 soon after DC 1 failure.

Reconfigure the load balancer by exposing DC 2 to the client.

2. During the failback process:

Run the following command in DC 2 to back up the data:

apigatewayUtil.sh create backup -name backup_file_name

Run the following command in DC 1 to restore the backed up data:

apigatewayUtil.sh restore backup -name backup_file_name

Restart API Gateway in DC 1.

Reconfigure the load balancer by exposing DC 1 to the client.