Configuration

Redis operator configuration

How are pods scheduled?

The Redis nodes are scheduled on K8s nodes according to pod affinity rules equivalent to the YAML configurations below.

For the leaders:

podAntiAffinity:
  requiredDuringSchedulingIgnoredDuringExecution:
  - labelSelector:
      matchExpressions:
      - key: "app"
        operator: In
        values:
        - "redis"
    topologyKey: "kubernetes.io/hostname"
  preferredDuringSchedulingIgnoredDuringExecution:
  - weight: 100
    podAffinityTerm:
      labelSelector:
        matchExpressions:
        - key: "redis-node-role"
          operator: In
          values:
          - "leader"
      topologyKey: "failure-domain.beta.kubernetes.io/zone"

For the followers (replicas):

podAntiAffinity:
  requiredDuringSchedulingIgnoredDuringExecution:
  - labelSelector:
      matchExpressions:
      - key: "app"
        operator: In
        values:
        - "redis"
    topologyKey: "kubernetes.io/hostname"
  preferredDuringSchedulingIgnoredDuringExecution:
  - weight: 100
    podAffinityTerm:
      labelSelector:
        matchExpressions:
        - key: "redis-node-role"
          operator: In
          values:
          - "leader"
        - key: "redis-cluster-id"
          operator: In
          values:
          - <leader-number>
      topologyKey: "failure-domain.beta.kubernetes.io/zone"

Configuration example

apiVersion: db.payu.com/v1
kind: RedisCluster
metadata:
  name: rdc-test
  namespace: infra
spec:
  leaderCount: 3
  leaderFollowersCount: 2
  image: "redis:testing"
  initContainer:
    image: "redis-init:testing"
  prometheusExporter:
    port: 9121  
    image: metrics-exporter:testing
  imagePullSecrets: "regcred"
  redisContainerResources:
    limits:
      cpu: 500m
      memory: 500Mi
    requests:
      cpu: 50m
      memory: 50Mi
  podLabelSelector:
    app: "redis"
  podAnnotations:
    sidecar.istio.io/inject: "false"
  affinity:
    hostTopologyKey: "kubernetes.io/hostname"
    zoneTopologyKey: "failure-domain.beta.kubernetes.io/zone"
  redisContainerEnvVariables:
    - name: PORT
      value: '6379'
    - name: CONF_PATH
      value: '/usr/local/etc/redis/redis.conf'

Field Name	Mandatory	Type	Description
prometheusExporter	False	Dictionary: image,port,imagePullPolicy	Prometheus exporter side car. Recommended: https://github.com/oliver006/redis_exporter
initContainer	False	Dictionary image,enabledHugepage,imagePullPolicy