Blue-Green Deployment

A blue-green deployment strategy is considered an expensive deployment option because it requires maintaining two identical production environments, blue and green. The blue environment caters to the live production traffic. In contrast, the green environment is an identical copy of the blue environment, except that the next application version has been deployed to it, and it does not serve live traffic.

Deployment steps

The blue-green deployment strategy typically involves the following steps in switching the live traffic to the new environment:

• The green environment is exclusively used for performing functional and nonfunctional tests.

• Once all the tests pass and SLAs are met, the DNS is reconfigured to switch the traffic to the green environment.

• Once the DNS is reconfigured, no new traffic enters the blue environment, but they remain active until all the in-flight requests are gracefully handled.

• The green environment receives all production traffic. The operations team continues to monitor the new application version for performance issues or application errors.

• Once it's confirmed that the new release is successful, the green environment is labeled as the new blue and continues to receive production traffic. The blue environment is marked as the new green and is ready to host the latest version once ...