As discussed in marathon groups here, I open this issue to track this feature request.
> Hi all,
> We're running marathon 0.9.2 + mesos 0.21.0 in product environment with great experience.
> As marathon targets to hosting log-running service and we run some web apps on marathon and experienced upgrade apps by upgrading it's docker image.
> However, after go though marathon docs(https://mesosphere.github.io/marathon/docs/) we found that seems marathon doesn't support user controllable upgrade policy but documented some hints to do BLUE-GREEN deployment.
> What we mean "user controllable app upgrade policy" like below:
> 1. user controlled what percentage of running containers will be upgraded
> 2. after configured percentage of running containers upgraded, stop for a period user specified, like, 1day, 1week or forever until receive next instruction.
> Though we can do that based on BLUE-GREEN deployment, but it's much complicated since you have two apps, and we'll merge both them into load balancer or proxy, that means some hacks by hand or in code.
> Is there any plan to implement "user controllable app upgrade policy" or such a feature deserved a PR?