StatefulSets¶

StatefulSets manage stateful applications that require stable identities and persistent storage.

They are commonly used for:

databases
distributed systems
clustered applications

Key Characteristics¶

Feature	Description
Stable Pod Names	pods keep consistent names
Ordered Deployment	pods start sequentially
Persistent Storage	each pod gets its own volume
Stable Network Identity	predictable DNS names

StatefulSet Example¶

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mysql
spec:
  serviceName: "mysql"
  replicas: 3
  selector:
    matchLabels:
      app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - name: mysql
        image: mysql:8

Pod Naming

Pods are named sequentially:

mysql-0
mysql-1
mysql-2

Persistent Volume Claims¶

Each pod receives its own storage:

mysql-data-mysql-0
mysql-data-mysql-1
mysql-data-mysql-2

Commands¶

View StatefulSets:

kubectl get statefulset

Describe:

kubectl describe statefulset <name>

Delete:

kubectl delete statefulset <name>