Blue-green deployment is a technique for rolling out software updates in which two identical production environments, known as blue and green, are used. At any given time, only one of the environments is live, while the other one is idle. When a new version of the software is ready to be deployed, it is first released to the idle environment.

This can be done by updating the application code, configuring the infrastructure, and running any necessary tests.

Once the new version has been deployed to the idle environment and tested, it can be switched to the live environment by updating a load balancer or a DNS record to route traffic to the new version. This switchover is typically done quickly, in a matter of seconds or minutes, to minimize downtime.

Below are the advantages of blue-green deployment:

• It allows for a quick rollback if something goes wrong with the new version.

• If there are any issues with the new version, it can be immediately switched back to the previous version by updating the load balancer or DNS record.

• This ensures that the software is always available and minimizes the impact of software updates on users.