Set up Auto Scaling Apps

Question

Is it possible to setup auto-scaling capabilities for an app depending on the workload? I haven't found anything useful neither in the Developer Console nor in the docs. Is there may be a hidden possibility via the CLI?

Just wondering if this is possible as I'm doing a basic evaluation on Swisscom Application Cloud.

Answer 1

There are several opensource autoscaling projects of various readiness for production use like

• https://github.com/cloudfoundry-incubator/app-autoscaler
• https://github.com/cloudfoundry-samples/cf-autoscaler

Pivotal Cloud Foundry supports auto-scaling of the applications out of the box (http://docs.pivotal.io/pivotalcf/1-8/appsman-services/autoscaler/autoscale-configuration.html)

Answer 2

This capability is not present at the moment, and it is not part of the (open source) cloudfoundry platform either. Some platforms provide it, but this has not been released to the community yet!

Answer 3

There are various ways how you can do that. As described by Anatoly, you can obvisouly use the "Auto Scaler" Service, if this is deployed from your respective Provider.

(you can figure that out by just calling this Feature-Flags-API check: https://apidocs.cloudfoundry.org/253/feature_flags/get_the_app_scaling_feature_flag.html)

An other option is actually writing your own small auto-scaler based on the custom-defined scaling-behaviours you've to meet your application. (DIY ;))

• Get Load : First you need to get information about your current "load" of the app (i.e. memory usage, cpu usage etc). You can easily do that by pulling data from the v2/apps//stats API. See details here: https://apidocs.cloudfoundry.org/253/apps/get_detailed_stats_for_a_started_app.html

• Write some magic : Now you need to write some magic around to verify if the app is under heavy load. Could be CPU or Memory or other bottle necks you try to get our of the stats API.

• Scale up/down : With the PUT v2/apps// API you can easily now change the amount of instances of your app by filling the paramter "instances" accordingly. https://apidocs.cloudfoundry.org/253/apps/updating_an_app.html

Answer 4

For PCF you can take a look at this https://github.com/Pivotal-Field-Engineering/autoscaling-cli-plugin. It should give you what you are looking for.

You will need to install it via the

cf install-plugin https://github.com/pivotal-cf-experimental/autoscaling-cli-plugin

and configure using steps similar to below

Get the details of the autoscaler from your marketplace

cf m | grep app-autoscaler

Install the auto scaler plugin using service & plan from above

cf create-service <service> <plan> myAutoScaler

Bind the service to your app (or u can do this via you deployment manifest)

cf bind-service myApp myAutoScaler

Configure your scaling parameters

cf configure-autoscaling --min-threshold ## --max-threshold ## --max-instances # --min-instances # myApp myAutoScaler