Running Redis on Kubernetes#
Redis on Kubernetes ranges from dead simple (single pod for caching) to operationally complex (Redis Cluster with persistence). The right choice depends on whether you need data durability, high availability, or just a fast throwaway cache.
Single-Instance Redis with Persistence#
For development or small workloads, a single Redis Deployment with a PVC is enough:
apiVersion: apps/v1
kind: Deployment
metadata:
name: redis
spec:
replicas: 1
selector:
matchLabels:
app: redis
template:
metadata:
labels:
app: redis
spec:
containers:
- name: redis
image: redis:7-alpine
command: ["redis-server", "--appendonly", "yes", "--maxmemory", "256mb", "--maxmemory-policy", "allkeys-lru"]
ports:
- containerPort: 6379
volumeMounts:
- name: redis-data
mountPath: /data
resources:
requests:
cpu: 100m
memory: 300Mi
limits:
cpu: 500m
memory: 350Mi
volumes:
- name: redis-data
persistentVolumeClaim:
claimName: redis-data
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: redis-data
spec:
accessModes: ["ReadWriteOnce"]
resources:
requests:
storage: 5Gi
---
apiVersion: v1
kind: Service
metadata:
name: redis
spec:
selector:
app: redis
ports:
- port: 6379
targetPort: 6379
Set the memory limit in Redis (--maxmemory) lower than the container memory limit. If Redis uses 350Mi and the container limit is 350Mi, the kernel OOM-kills the process during background save operations when Redis forks and temporarily doubles its memory usage. A safe ratio: set maxmemory to 60-75% of the container memory limit.
