Blue-Green Deployment
Blue-Green Deployment is a release technique that reduces downtime and risk by running two identical production environments called Blue and Green.
At any time, only one of the environments is live, with the live environment serving all production traffic. For this example, Green is currently live and Blue is idle. As you prepare a new release of your software, deployment and the final stage of testing takes place in the environment that is not live: in this example, Blue. Once you have deployed and fully tested the software in Blue, you switch the router so all incoming requests now go to Blue instead of Green. Blue is now live, and Green is idle.
This technique can eliminate downtime due to application deployment. In addition, blue-green deployment reduces risk: if something unexpected happens with your new release on Blue, you can immediately roll back to the last version by switching back to Green.
Deployment Risks
In the image above, we can see some common deployment risks that we may face due to unplanned deployments. It might not affect a lot for small patch/update release but for a major release or a big update to go live, it affects a lot. So to reduce deployment risks, Blue-Green Deployment plays a crucial role.
