A failover configuration establishes a primary and backup relationship between two servers or domains. Our authoritative name servers will send all traffic to the primary server/domain until it fails a majority of its health checks. At which point, all traffic will be redirected to the backup server/domain.
The following illustration shows the process through which all requests are resolved to the IP address of a primary server.
A health check configuration plays a major role in determining when to fail traffic over to a backup server/domain. Once a health check configuration has been established, a server/domain will be polled at regular intervals to ensure that it is still healthy.
In the following illustration, both the primary and backup servers have passed a majority of their health checks. All traffic is directed to the primary web server as a result of a failover configuration.
If the primary server fails a majority of its health checks, our DNS service will redirect all traffic to the backup server. This is illustrated below.
In the above scenario, traffic will continue to be served to the backup server until the primary server is reintegrated back into the failover configuration. At which point, our DNS service will redirect all traffic to the primary server.
Edgecast CDN