☁️ Free practice test question from: KCNA (KCNA)

StatefulSet is specifically designed for applications that need:

1. Stable, unique network identifiers - Each pod gets a predictable hostname based on an index (like database-0, database-1), which is crucial for database clustering where nodes need to know about each other.

2. Stable, persistent storage - StatefulSets allow you to attach persistent volumes to specific pods, ensuring data survives pod restarts or rescheduling.

3. Ordered, graceful deployment and scaling - Pods are created in sequence (from 0 to N-1) and terminated in reverse order. This is essential for database operations like primary election or data replication.

4. Ordered, automated rolling updates - Updates can happen in a controlled fashion, which is critical for database availability.

In practice, you'd use a StatefulSet to deploy databases like MongoDB, PostgreSQL clusters, or Elasticsearch, where each instance needs its own persistent storage and stable identity within the cluster.