This repository consists of everything you need to setup simple Kubernetes cluster and demonstrate usage of KEDA redis and mysql scalers. For more samples check https://github.com/kedacore/samples
The included helper
provides an easy way to perform both 0 -> n and n -> 0 scalings.
The deployment consists of 4 components:
- MySQL instance
- Redis instance
- Dummy pod that will be scaled up and down
- App service that provides some helper methods
kubectl apply -f deployment/
Follow the official KEDA guide https://keda.sh/deploy/
To observe how everything works you can watch two things:
- number of pods and their state:
watch -n2 "kubectl get pods"
- HPA stats:
watch -n2 "kubectl get hpa"
To scale the dummy deployment using
Redis scaler first we have to
deploy the ScaledObjects
:
kubectl apply -f keda/redis-hpa.yaml
this should result in creation of a new ScaledObjects
and new HPA
# kubectl get scaledobjects
NAME DEPLOYMENT TRIGGERS AGE
redis-scaledobject dummy redis 5s
# kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
keda-hpa-dummy Deployment/dummy <unknown>/10 (avg) 1 4 0 45s
To scale up we have to populate the Redis queue. To do this we can use the helper app:
kubectl exec $(kubectl get pods | grep "server" | cut -f 1 -d " ") -- keda-talk redis publish
and to scale down:
kubectl exec $(kubectl get pods | grep "server" | cut -f 1 -d " ") -- keda-talk redis drain
To scale the dummy deployment using
MySQL scaler first we have to
deploy the ScaledObjects
:
kubectl apply -f keda/mysql-hpa.yaml
this should result again in creation of ScaleObject
and an HPA:
# kubectl get scaledobjects
NAME DEPLOYMENT TRIGGERS AGE
mysql-scaledobject dummy redis 5s
# kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
keda-hpa-dummy Deployment/dummy <unknown>/10 (avg) 1 4 0 45s
To scale up we have to insert some values to MySQL database. To do this we can use the helper app:
kubectl exec $(kubectl get pods | grep "server" | cut -f 1 -d " ") -- keda-talk mysql insert
and to scale down:
kubectl exec $(kubectl get pods | grep "server" | cut -f 1 -d " ") -- keda-talk mysql delete