Static content, including js files: like everybody says in this thread, you should use cache busting (add hash of file to filename) regardless of canary/blue-gr

Static content, including js files: like everybody says in this thread, you should use cache busting (add hash of file to filename) regardless of canary/blue-green pattern. Back end services: use a cookie or a header. Once a user is selected for canary'ing a device, they get a special value in a header, and your service router sends their requests to the right set of servers.