My understanding of a canary release is that it's a partial release to a subset of production nodes with sticky sessions turned on. That way you can control and minimize the number of users/customers that get impacted if you end up releasing a bad bug.
My understanding of a blue/green release is that you have 2 mirrored production environments ("blue" and "green"), and you push changes out to all the nodes of either blue or green at once, and then use networking magic to control which environment users are routed to via DNS.
So, before I begin, if anything I have said so far is incorrect, please begin by correcting me!
Assuming I'm more or less on track, then a couple of questions about the two strategies:
- Are there scenarios where canary is preferred over blue/green, and vice versa?
- Are there scenarios where a deployment model can implement both strategies at the same time?