BlueGreenDeployment

“There are many ways to provide for failover and clustered services.  One very specific way to achieve high availability that allows for leap-frog releases cycles is blue-green deployments.  The idea is to have a mirrored setup where release code runs one one environment and pre-release code runs on the other.  This creates an environment that provides rollback, reliability, failover and a host of other capabilities.”

“Blue-green deployment allows you to upgrade production software without downtime. You deploy the new version into a copy of the production environment and change routing to switch.”

Source: BlueGreenDeployment