blue-green-deploymentdeployment
What's the difference between a blue/green deployment and a rolling deployment? I always thought that a blue/green deployment was a sudden switch of traffic from the old version to the new version immediately.
This talk about Blue/Green deployment on AWS shows various different strategies to implement a blue/green deployment, but they also seem to match the definition of a rolling deployment.
Is a blue/green deployment a subset of rolling deployments?
I have written a detailed essay on this topic here: http://blog.itaysk.com/2017/11/20/deployment-strategies-defined
In my opinion, the difference is whether or not the new 'green' version is exposed to real users. If it is, then I'd call it Canary. A common way to implement Canary is regular Blue/Green with the addition of smart routing of specific users to the new version. Read the post for a detailed comparison
Blue/Green:
Canary:
Best Answer
I have written an essay on this topic here: http://blog.itaysk.com/2017/11/20/deployment-strategies-defined
In my opinion the difference is whether the new version is applied by replacing instances in the existing setup (in the case of rolling upgrade), or a completely isolated setup is created for the new version (in the case of Blue/Green). In my opinion Blue/Green is the safest strategy and is better in most cases for production deployments. Read the post for a detailed comparison.