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Moar! I want moar!

Autoskalowanie w kubernetesie na przykładzie OpenShift 4.0

Paweł Krupa

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Czym jest (auto)skalowanie?

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Red Hat

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Vertical

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Red Hat

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Horizontal

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Red Hat

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Gdzie to “auto”?

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Red Hat

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Feedback Loop

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Red Hat

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Feedback Loop

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Red Hat

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Feedback Loop

8

Red Hat

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9

Red Hat

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10

Red Hat

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kubernetes autoscalers

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Vertical Pod Autoscaler (VPA)

Horizontal Pod Autoscaler (HPA)

Cluster Autoscaler

Red Hat

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Resources and scheduling

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apiVersion: v1

kind: Pod

metadata:

name: frontend

spec:

containers:

- name: db

image: mysql

env:

- name: MYSQL_ROOT_PASSWORD

value: "password"

resources:

requests:

memory: "64Mi"

cpu: "250m"

limits:

memory: "128Mi"

cpu: "500m"

- name: wp

image: wordpress

resources:

requests:

memory: "64Mi"

cpu: "250m"

limits:

memory: "128Mi"� cpu: "500m"

Red Hat

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Resources and scheduling

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200m

600m

node 900m

node 900m

600m

200m

600m

200m

Red Hat

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Vertical Pod Autoscaler

14

Red Hat

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Vertical Pod Autoscaler

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node 900m

node 900m

Red Hat

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Vertical Pod Autoscaler

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node 900m

node 900m

Red Hat

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Vertical Pod Autoscaler

  • Loosely coupled set of applications
  • Changes resource requests not limits!
  • Makes decisions based on historical data
  • VPA Recommender (calculate memory and cpu values based on historic metrics)
  • Experimental :-)

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Red Hat

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Vertical Pod Autoscaler

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VPA

Pod

Metrics

RC/Deployment

Pod

Red Hat

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Horizontal Pod Autoscaler

19

Red Hat

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Horizontal Pod Autoscaler

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HPA

Pod

Metrics

RC/Deployment

Pod

Pod

Red Hat

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node 900m

node 900m

600m

200m

200m

200m

200m

200m

200m

200m

Red Hat

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node 900m

node 900m

600m

200m

200m

200m

200m

200m

200m

200m

200m

200m

200m

200m

200m

200m

Red Hat

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Cluster Autoscaler

23

Red Hat

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Cluster Autoscaler

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Pod

Pod

Pod

Pending

CA

Pod

Pending

node 900m

Pod

Pod

Red Hat

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OpenShift Cluster Autoscaler

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Pod

Pod

Pod

Pending

CA

Pod

Pending

node 900m

Pod

Pod

Machine API Operator

Red Hat

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node 900m

node 900m

600m

200m

200m

200m

200m

200m

200m

200m

200m

200m

200m

200m

Red Hat

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node 900m

node 900m

600m

200m

200m

200m

200m

200m

200m

200m

200m

200m

node 900m

200m

200m

200m

200m

Red Hat

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TL;DR;

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Red Hat

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node

node

CA

Pod

2. Pods pending

Pod

HPA

VPA

1. Change resources

3. Additional nodes allocated

4. Pods scheduled

Pod

Red Hat

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Demo time!

30

Red Hat

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THANK YOU

github.com/paulfantom

paulfantom@gmail.com

twitter.com/paulfantom

pkrupa@redhat.com