Is auto-scaling at a VM-level (cell-level) possible in Cloud Foundry? If yes, how can this be achieved?

Question

I have seen two levels of scaling instances in open-source Cloud Foundry.

cf scale -i INSTANCES
cf scale -m MEMORY -k DISK

Is there something available for a cell-level auto-scaling in CF? eg If I have 5 instances of an app running and I want to launch 15 more but the current no. of cell VMs that are running have a capacity of running only 15 instances in total. Can I use an existing service that recognises that the load to be served would need one more cell to be launched and spawn another machine? I'm looking to deploy CF on Azure, so Azure-specific solution would also help.

Answer 1

I think the short answer is no (at least at the time of me writing this). Usually, Cloud Foundry is deployed using Bosh and Bosh does not have an auto scaling feature.

The way that a CF platform is typically managed is that as a CF operator, you would have monitoring setup so that you can see the capacity of your platform ( there are metrics that tell you how much capacity is left on your Cells) and also alert when your platform hits certain capacity limits. When you reach these, you can then use Bosh to scale up or down the number of Cells accordingly. This would be a manual operation with Bosh though.

Having said that, I suppose there's nothing to stop you from using the alerts to automatically trigger Bosh to scale up or down the Cells, there's just nothing (as of me writing this) to do that out-of-the-box (ie part of Bosh itself).

Hope that helps!