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

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About this task

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, DC 1 serves the traffic, and in DC2, only API Data Store is up and running, whereas API Gateway is in a shutdown state.

Pre-requisites

  • Install webMethods API Gateway in DC2 and ensure that the fix upgrades of DC1 is applied to DC2 too.
  • Run the following backup REST API periodically to take a snapshot of data from DC1 and store the snapshots in a suitable externalized storage system based on the RPO: 
    curl -si -X POST -H "content-type:application/json" -d '{"indices": "gateway_tenant_*"}' http://es-host:es-port/_snapshot/repo-name/backup_file_name
  • Run the following restore REST API periodically to restore the backup snapshots from the externalized storage in DC2. 
    curl -si -X POST -H "content-type:application/json" -d '{"indices": "gateway_tenant_*"}' http://es-host:es-port/_snapshot/repo-name/backup_file_name/_restore

For more information about backup and restore, see Data Backup

Failover and Failback process

Procedure

  1. During the failover process:
    • Restart webMethods API Gateway in DC2.

      As API Data Store is up and running and the data is already restored from the snapshots in API Data Store, you just have to restart webMethods API Gateway in DC 2. The downtime for this mode would be only the time until API Gateway is up.

    • 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: 
      curl -si -X POST -H "content-type:application/json" -d '{"indices": "gateway_tenant_*"}' http://es-host:es-port/_snapshot/repo-name/backup_file_name
    • Run the following command in DC 1 to restore the backed up data: 
      curl -si -X POST -H "content-type:application/json" -d '{"indices": "gateway_tenant_*"}' http://es-host:es-port/_snapshot/repo-name/backup_file_name/_restore
    • Restart webMethods API Gateway in DC 1.
    • Reconfigure the load balancer by exposing DC 1 to the client.