When you are deploying a new change into production, the associated deployment should be in a predictable manner. In simple terms, this means no disruption and zero downtime! In case you do encounter a problem or a bottleneck, the deployment strategy should include a quick roll back.

The safe strategy can be achieved by working with two identical infrastructures - the “green” environment hosting the current production and the “blue” environment with the new changes.

The business and IT teams will have an opportunity to conduct sanity, smoke test or any other test in the “blue” environment before making a “Go” decision. Upon “Go”, the team can switch “blue” to “green” and “green” to “blue”.

In Azure, different processes are available for implementing the Blue-Green strategy with two environments.

We have listed below some of these techniques. Naturally, this list is not fixed and will grow continuously as new tool sets and services emerge.

• Deployment slots - For Web Apps, deployment slots provide an easy way to implement Blue-Green deployments.
• Azure Traffic Manager – This can be leveraged to realize Blue-Green deployments for smoother deployments with weighted round-robin routing method. The detailed configuration and implementation methods are available in Azure Documentation.
• Using an Application Gateway with two backend pools and a routing rule - Have two backend resource pools with one as a stage pool and another one as a prod pool. Add stage VMSS to stage pool, prod VMSS to prod pool and have one routing rule in the app gateway. Depending on the need to use stage or prod VMSS, this rule will be changed to point to the appropriate backend address pool.

CloudIQ architects and engineers have implemented Blue-Green deployment for multiple clients, and in each case, we have customized our strategies to suit their use-cases. If you are looking for a completely safe way to deploy new software versions and applications, then reach out to us at [email protected]