Problem Statement
You need to migrate a stateful application from one Kubernetes cluster to another (different region) with zero or minimal downtime. What strategy do you follow for data, volumes, services and DNS? What tools might you use and how do you ensure consistency and application integrity?
Explanation
First I would ensure the source cluster’s PersistentVolumes are snapshotted or backed up incrementally, leveraging cloud-native snapshot tools or volume migration mechanisms. Meanwhile I’d deploy the target cluster, provision equivalent StorageClass and PersistentVolumes, restore data and validate state. I’d update Service endpoints to point to the new application or use a load-balancer/ingress with blue-green traffic switch. DNS might need TTL reduction so cut-over happens quickly. I’d use tools like Velero for backup/restore, or cloud provider volume replication. I’d test traffic routing and readiness, and finally redirect traffic once target pods pass health checks. This kind of scenario tests real-world readiness for stateful workloads in Kubernetes. :contentReference[oaicite:3]{index=3}
