In the case of a disaster, we can leverage sophisticated monitoring techniques. Route 53 can be used to monitor the primary environment endpoint; if the primary web environment consists of multiple health checks, a calculated health check can be used to gain a wider understanding of the health of your services.

The failover routing policy provides records that can be configured as ALIAS (for CNAMES DNS) or as type A (for IP addresses). The health check string matching feature allows you to find a specific string or pattern in the check response. An example is as follows:

{ 
   "STATUS"    : "OK", 
   "DB"        : "UP", 
   "MQ"        : "UP", 
   "API"             : "UP" 
} 

Route 53 will automatically fail over to the warm standby, and, with the use of Lambda (as in the backup and restore strategy), the pilot can be triggered to initiate the furnace, by starting the web server, adjusting the AutoScaling limits so that the pilot light environment can accommodate the current load of the production environment; this could take several minutes to be fully usable and horizontally scale to match the current demand.

Some of the relevant services are as follows:

• Relational Database Service (RDS)

• Database Migration Service (DMS)