hpa + ca into one guide

This commit is contained in:
marcel-dempers 2020-08-25 21:41:56 +10:00
parent 641b16ab12
commit 2798c4bb3f
8 changed files with 40 additions and 308 deletions

View File

@ -1,136 +0,0 @@
# Cluster Autoscaling
Scales the number of nodes in our cluster based off usage metrics
[Documentation](https://github.com/kubernetes/autoscaler/tree/master/cluster-autoscaler)
## Understanding Resources
In this example, I'll be focusing on CPU for scaling. <br/>
We need to ensure we have an understanding of the compute resources we have. <br/>
1) How many cores do we have <br/>
2) How many cores do our application use <br/>
I go into more details about pod resource utilisation in the Horizontal Pod Autoscaler guide.
# We need a Kubernetes cluster with Cluster Autoscaler
```
# azure example
NAME=aks-getting-started
RESOURCEGROUP=aks-getting-started
SERVICE_PRINCIPAL=
SERVICE_PRINCIPAL_SECRET=
az aks create -n $NAME \
--resource-group $RESOURCEGROUP \
--location australiaeast \
--kubernetes-version 1.16.10 \
--nodepool-name default \
--node-count 1 \
--node-vm-size Standard_F4s_v2 \
--node-osdisk-size 250 \
--service-principal $SERVICE_PRINCIPAL \
--client-secret $SERVICE_PRINCIPAL_SECRET \
--output none \
--enable-cluster-autoscaler \
--min-count 1 \
--max-count 5
```
# Deploy Metric Server
[Metric Server](https://github.com/kubernetes-sigs/metrics-server) provides container resource metrics for use in autoscaling pipelines
We will need to deploy Metric Server [0.3.7](https://github.com/kubernetes-sigs/metrics-server/releases/tag/v0.3.7) <br/>
I used `components.yaml`from the release page link above. <br/>
Note: For Demo clusters (like `kind`), you will need to disable TLS <br/>
You can disable TLS by adding the following to the metrics-server container args
```
- --kubelet-insecure-tls
- --kubelet-preferred-address-types="InternalIP"
```
Deploy it:
```
cd kubernetes\autoscaling
kubectl -n kube-system apply -f .\metric-server\metricserver-0.3.7.yaml
#test
kubectl -n kube-system get pods
#wait for metrics to populate
kubectl top nodes
```
## Example App
We have an app that simulates CPU usage
```
# build
cd kubernetes\autoscaling\application-cpu
docker build . -t aimvector/application-cpu:v1.0.0
# push
docker push aimvector/application-cpu:v1.0.0
# resource requirements
resources:
requests:
memory: "50Mi"
cpu: "500m"
limits:
memory: "500Mi"
cpu: "2000m"
# deploy
kubectl apply -f deployment.yaml
# metrics
kubectl top pods
```
## Generate some CPU load
```
# Deploy a tester to run traffic from
cd kubernetes/autoscaling
kubectl apply -f ./autoscaler-cluster/tester.yaml
# get a terminal
kubectl exec -it tester sh
# install wrk
apk add --no-cache wrk curl
# simulate some load
wrk -c 5 -t 5 -d 99999 -H "Connection: Close" http://application-cpu
# scale and keep checking `kubectl top`
# every time we add a pod, CPU load per pod should drop dramatically.
# roughly 8 pods will have each pod use +- 400m
kubectl scale deploy/application-cpu --replicas 2
```
## Deploy an autoscaler
```
# scale the deployment back down to 2
kubectl scale deploy/application-cpu --replicas 2
# deploy the autoscaler
kubectl autoscale deploy/application-cpu --cpu-percent=95 --min=1 --max=10
# pods should scale to roughly 7-8 to match criteria
kubectl describe hpa/application-cpu
kubectl get hpa/application-cpu -owide
```

View File

@ -1,18 +0,0 @@
apiVersion: v1
kind: Pod
metadata:
name: traffic-generator
spec:
containers:
- name: alpine
resources:
requests:
memory: "50Mi"
cpu: "500m"
limits:
memory: "500Mi"
cpu: "2000m"
image: alpine
args:
- sleep
- "100000000"

View File

@ -1,32 +0,0 @@
# Horizontal Pod Autoscaling
Scales the number of pods in a deployment based off metrics.
Kubernetes [documentation](https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/)
## Understanding Resources
In this example, I'll be focusing on CPU for scaling. <br/>
We need to ensure we have an understanding of the compute resources we have. <br/>
1) How many cores do we have <br/>
2) How many cores do our application use <br
# scale and keep checking `kubectl top`
# every time we add a pod, CPU load per pod should drop dramatically.
# roughly 8 pods will have each pod use +- 400m
## Deploy an autoscaler
```
# scale the deployment back down to 2
kubectl scale deploy/application-cpu --replicas 2
# deploy the autoscaler
kubectl autoscale deploy/application-cpu --cpu-percent=95 --min=1 --max=10
# pods should scale to roughly 7-8 to match criteria
kubectl describe hpa/application-cpu
kubectl get hpa/application-cpu -owide
```

View File

@ -1,105 +0,0 @@
# Vertical Pod Autoscaling
Provides recommendations for CPU and Memory request values.
## Understanding Resources
In this example, I'll be focusing on CPU for scaling. <br/>
We need to ensure we have an understanding of the compute resources we have. <br/>
1) How many cores do we have <br/>
2) How many cores do our application use <br/>
3) Observe our applications usage
4) Use the VPA to recommend resource request values for our application
## Create a cluster
My Node has 6 CPU cores for this demo <br/>
```
kind create cluster --name vpa --image kindest/node:v1.18.4
```
# Deploy Metric Server
[Metric Server](https://github.com/kubernetes-sigs/metrics-server) provides container resource metrics for use in autoscaling pipelines
We will need to deploy Metric Server [0.3.7](https://github.com/kubernetes-sigs/metrics-server/releases/tag/v0.3.7) <br/>
I used `components.yaml`from the release page link above. <br/>
Note: For Demo clusters (like `kind`), you will need to disable TLS <br/>
You can disable TLS by adding the following to the metrics-server container args <br/>
For production, make sure you remove the following : <br/>
```
- --kubelet-insecure-tls
- --kubelet-preferred-address-types="InternalIP"
```
Deploy it:
```
cd kubernetes\autoscaling
kubectl -n kube-system apply -f .\metric-server\metricserver-0.3.7.yaml
#test
kubectl -n kube-system get pods
#wait for metrics to populate
kubectl top nodes
```
## Example App
We have an app that simulates CPU usage
```
# build
cd kubernetes\autoscaling\application-cpu
docker build . -t aimvector/application-cpu:v1.0.0
# push
docker push aimvector/application-cpu:v1.0.0
# resource requirements
resources:
requests:
memory: "50Mi"
cpu: "500m"
limits:
memory: "500Mi"
cpu: "2000m"
# deploy
kubectl apply -f deployment.yaml
# metrics
kubectl top pods
```
## Generate some CPU load
```
# Deploy a tester to run traffic from
cd kubernetes\autoscaling
kubectl apply -f .\autoscaler-vpa\tester.yaml
# get a terminal
kubectl exec -it tester sh
# install wrk
apk add --no-cache wrk curl
# simulate some load
wrk -c 5 -t 5 -d 99999 -H "Connection: Close" http://application-cpu
# scale and keep checking `kubectl top`
# every time we add a pod, CPU load per pod should drop dramatically.
# roughly 8 pods will have each pod use +- 400m
kubectl scale deploy/application-cpu --replicas 2
```

View File

@ -1,11 +0,0 @@
apiVersion: v1
kind: Pod
metadata:
name: traffic-generator
spec:
containers:
- name: alpine
image: alpine
args:
- sleep
- "100000000"

View File

@ -88,6 +88,8 @@ spec:
args:
- --cert-dir=/tmp
- --secure-port=4443
- --kubelet-insecure-tls
- --kubelet-preferred-address-types="InternalIP"
ports:
- name: main-port
containerPort: 4443

View File

@ -3,6 +3,8 @@
## Cluster Autoscaling
Cluster autoscaler allows us to scale cluster nodes when they become full <br/>
I would recommend to learn about scaling your cluster nodes before scaling pods. <br/>
Video [here](https://youtu.be/jM36M39MA3I)
## Horizontal Pod Autoscaling
@ -50,7 +52,6 @@ My Node has 6 CPU cores for this demo <br/>
kind create cluster --name hpa --image kindest/node:v1.18.4
```
### Metric Server
* For `Cluster Autoscaler` - On cloud-based clusters, Metric server may already be installed. <br/>
@ -78,12 +79,12 @@ Deployment: <br/>
```
cd kubernetes\autoscaling
kubectl -n kube-system apply -f .\metric-server\metricserver-0.3.7.yaml
kubectl -n kube-system apply -f .\components\metric-server\metricserver-0.3.7.yaml
#test
kubectl -n kube-system get pods
#wait for metrics to populate
#note: wait for metrics to populate!
kubectl top nodes
```
@ -101,7 +102,7 @@ For all autoscaling guides, we'll need a simple app, that generates some CPU loa
```
# build
cd kubernetes\autoscaling\application-cpu
cd kubernetes\autoscaling\components\application
docker build . -t aimvector/application-cpu:v1.0.0
# push
@ -124,17 +125,48 @@ kubectl top pods
```
## Cluster Autoscaler
For cluster autoscaling, you should be able to scale the pods manually and watch the cluster scale. </br>
Cluster autoscaling stops here. </br>
For Pod Autoscaling (HPA), continue</br>
## Generate some traffic
Let's deploy a simple traffic generator pod
```
cd kubernetes\autoscaling\components\application
kubectl apply -f .\traffic-generator.yaml
# get a terminal to the traffic-generator
kubectl exec -it traffic-generator sh
# install wrk
apk add --no-cache wrk curl
apk add --no-cache wrk
# simulate some load
wrk -c 5 -t 5 -d 99999 -H "Connection: Close" http://application-cpu
#you can scale to pods manually and see roughly 6-7 pods will satisfy resource requests.
kubectl scale deploy/application-cpu --replicas 2
```
```
## Deploy an autoscaler
```
# scale the deployment back down to 2
kubectl scale deploy/application-cpu --replicas 2
# deploy the autoscaler
kubectl autoscale deploy/application-cpu --cpu-percent=95 --min=1 --max=10
# pods should scale to roughly 6-7 to match criteria of 95% of resource requests
kubectl get pods
kubectl top pods
kubectl get hpa/application-cpu -owide
kubectl describe hpa/application-cpu
```