Feature: Add min/max scale for auto-scaling - Swarm & external providers

[alexellis]

Should be able to set a minimum scale for functions as well as the maximum (existing)

We can configure this through labels on the Docker Swarm service.

  labels:
    "com.openfaas.scale.min": "5"
    "com.openfaas.scale.max": "15"

Labels are generic so this would need faas-netes to expose some new data for the /system/function/ call too.

This will be useful for functions which are known to need to have high availability or traffic.

Implementation on Swarm:

• [x] Alert handler
• [x] Create handler
• [x] Update handler

cc @stefanprodan @ericstoekl

Initial work: https://github.com/openfaas/faas/compare/scale_with_min_values?expand=1

[stefanprodan]

Tested on Kubernetes with the following stack:

functions:
  nodeinfo:
    handler: node main.js
    image: functions/nodeinfo:burner
    labels:
      com.openfaas.scale.min: "5"
      com.openfaas.scale.max: "15"

It got up to 15 PODs during the load test and down to 5 after that:

[alexellis]

Thank you for helping to test this on Kubernetes Stefan.

That result sounds like what we want. When the settings are not present does it fallback to the old behavior?

[stefanprodan]

With no com.openfaas.scale.min label it goes back to one pod.

[alexellis]

Derek add label: enhancement

[austinfrey]

Is this closeable with the merge of #419?

[alexellis]

Derek close

[alexellis]

Yes thanks for helping out

[YasminBZ]

Hello please how i can autoscale my faas fucntion ??

[YasminBZ]

which command i use for example to fix the number of replica depend on the CPU usage or the number of requests ??

[alexellis]

@white-cloud this thread is closed - please open a new issue if you'd like support.

[alexellis]

Derek lock: feature completed