This page was generated from examples/models/autoscaling/autoscaling_example.ipynb.

Autoscaling Seldon Deployments

Prerequisites

• The cluster should have heapster and metric-server running in the kube-system namespace

• For Kind install ../../testing/scripts/metrics.yaml See https://github.com/kubernetes-sigs/kind/issues/398

• For Minikube run:

  minikube addons enable metrics-server
  minikube addons enable heapster
  

Setup Seldon Core

Use the setup notebook to Setup Cluster with Ambassador Ingress and Install Seldon Core. Instructions also online.

!kubectl create namespace seldon

!kubectl config set-context $(kubectl config current-context) --namespace=seldon

Create model with autoscaler

To create a model with an HorizontalPodAutoscaler there are three steps:

1. Ensure you have a resource request for the metric you want to scale on if it is a standard metric such as cpu or memory, e.g.:

resources:
  requests:
    cpu: '0.5'

1. Add an HPA Spec refering to this Deployment, e.g.:

- hpaSpec:
    maxReplicas: 3
    metrics:
    - resource:
        name: cpu
        targetAverageUtilization: 10
      type: Resource
    minReplicas: 1

The full SeldonDeployment spec is shown below.

!pygmentize model_with_hpa.yaml

!kubectl create -f model_with_hpa.yaml

!kubectl rollout status deploy/$(kubectl get deploy -l seldon-deployment-id=seldon-model -o jsonpath='{.items[0].metadata.name}')

Create Load

We label some nodes for the loadtester. We attempt the first two as for Kind the first node shown will be the master.

!kubectl label nodes $(kubectl get nodes -o jsonpath='{.items[0].metadata.name}') role=locust
!kubectl label nodes $(kubectl get nodes -o jsonpath='{.items[1].metadata.name}') role=locust

!helm install loadtester ../../../helm-charts/seldon-core-loadtesting  \
    --set locust.host=http://seldon-model-example:8000 \
    --set oauth.enabled=false \
    --set locust.hatchRate=1 \
    --set locust.clients=1 \
    --set loadtest.sendFeedback=0 \
    --set locust.minWait=0 \
    --set locust.maxWait=0 \
    --set replicaCount=1

After a few mins you should see the deployment my-dep scaled to 3 deployments

import json
import time

def getNumberPods():
    dp=!kubectl get deployment seldon-model-example-0-classifier -o json
    dp=json.loads("".join(dp))
    return dp["status"]["replicas"]

scaled = False
for i in range(60):
    pods = getNumberPods()
    print(pods)
    if pods > 1:
        scaled = True
        break
    time.sleep(5)
assert(scaled)

!kubectl get pods,deployments,hpa

Remove Load

After 5-10 mins you should see the deployments replicas decrease to 1

!helm delete loadtester -n seldon

!kubectl get pods,deployments,hpa

!kubectl delete -f model_with_hpa.yaml