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Docker & Kubernetes · Question Set
Networking, Storage & Scaling interview questions for placements and exams.
Questions
11
Included in this set
Subject
Docker & Kubernetes
Explore more sets
Difficulty
Mixed
Level of this set
Go through each question and its explanation. Use this set as a focused practice pack for Docker & Kubernetes.
A StorageClass provides the parameters and provisioner details for dynamically creating PersistentVolumes when a PVC requests storage. Using StorageClasses lets you abstract underlying storage infrastructure (e.g., SSD vs HDD, encrypted vs non-encrypted) and make storage request simple and flexible.
For complete preparation, combine this set with full subject-wise practice for Docker & Kubernetes. You can also explore other subjects and sets from the links below.
In Kubernetes each pod is assigned an IP address and is supposed to be able to reach any other pod in the cluster, regardless of node location and without NAT in the ideal model. This simplifies service-to-pod and pod-to-pod communication and avoids complex port mapping.
A Container Network Interface (CNI) plugin is responsible for providing networking for pods: allocating IP addresses, configuring interfaces, managing routing and enforcing network policies. Choosing the correct CNI is vital for security, performance and multi-node networking.
A Service of type LoadBalancer provisions a cloud provider’s external load-balancer and assigns the service an external IP so it can route traffic to backend pods directly. An Ingress resource works at layer-7 (HTTP/HTTPS) and allows routing requests based on host or path, often consolidating multiple services behind one load-balancer. Use LoadBalancer when you just need a simple external endpoint; use Ingress when you want more flexible routing, path-based rules or certificate termination.
The HorizontalPodAutoscaler (HPA) controller monitors metrics such as CPU utilization and adjusts the number of pod replicas dynamically to match load. This enables applications to scale out or in without manual intervention and improve resource usage efficiency.
A NetworkPolicy defines how groups of pods are allowed to communicate with each other and with other network endpoints. It acts like a firewall inside the cluster facilitating segmentation and enforcing least-privilege communication patterns.
Horizontal scaling means adding or removing pod replicas (scale-out) to handle variable load; vertical scaling means increasing CPU/memory of existing pods (scale-up). Example: a stateless web service might use HPA to horizontally scale out when traffic surges; a stateful analytics job might use vertical scaling if the workload remains on one pod but needs more memory and CPU. Choosing the right approach depends on application architecture and workload characteristics.
Kubernetes may evict pods when a node is under resource pressure, such as low memory, or when pods exceed their resource limits. Eviction frees node resources and protects system stability, so setting requests and limits is vital.
A robust backup and restore strategy involves using tools that snapshot PersistentVolumes or underlying storage, storing backups externally (cloud object store or off-cluster storage), verifying restore processes, and automating recovery drills. You must consider consistency (quiesce applications), retention, recovery time objective (RTO) and recovery point objective (RPO). For migration you may export data, set up new PVCs in the destination cluster, and restore volumes before pods start. This planning ensures data integrity and minimal downtime in production clusters.
A StatefulSet is used for applications that require stable network identifiers, ordered start-up or shutdown, and persistent storage tied to each replica (for example databases or message queues). When using a StatefulSet you must ensure each replica has a PersistentVolumeClaim bound to appropriate storage, define a StorageClass for dynamic provisioning, and consider storage performance, retention and backup. Using StatefulSet correctly is key for stateful workloads in Kubernetes production setups.
A PersistentVolume (PV) is a piece of storage in the cluster provisioned by an administrator or dynamically created, and it can be claimed by pods via PersistentVolumeClaims (PVCs). This separation provides flexibility in storage management and decouples storage from pods’ lifecycles.