Pods and deployments for services in Microservices - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary role of a Pod in Kubernetes?

Imagine you have a small team working together in a room to complete a task. In Kubernetes, a Pod is like that team. What is the main purpose of a Pod?

A It stores persistent data for containers to use.

B It manages the deployment and scaling of containers automatically.

C It acts as a load balancer to distribute traffic among services.

D It groups one or more containers that share storage and network resources.

💡 Hint

Think about what runs inside a Pod and what resources they share.

A Pod is the smallest deployable unit in Kubernetes. It groups containers that run together and share the same network and storage.

❓ Architecture

intermediate

How does a Deployment help manage Pods in Kubernetes?

Think of a Deployment as a manager who ensures the right number of workers (Pods) are always available. What is the main function of a Deployment?

A It ensures a specified number of Pods are running and updates them smoothly.

B It provides persistent storage to Pods for data retention.

C It schedules Pods to specific nodes based on resource availability.

D It routes external traffic directly to individual Pods.

💡 Hint

Consider how you keep a team size constant and update their tasks without disruption.

A Deployment manages the lifecycle of Pods by maintaining the desired number and performing rolling updates without downtime.

❓ scaling

advanced

What happens when you scale a Deployment from 3 to 6 replicas?

You have a Deployment running 3 Pods. You decide to scale it to 6. What is the expected behavior in Kubernetes?

A Kubernetes merges the 3 Pods into 6 containers within the same Pods.

B Kubernetes replaces the existing 3 Pods with 6 new Pods on the same nodes.

C Kubernetes creates 3 additional Pods to reach 6 total, distributing them across nodes.

D Kubernetes pauses all Pods and restarts 6 Pods sequentially.

💡 Hint

Think about how Kubernetes adds capacity without stopping existing Pods.

Scaling a Deployment increases the number of Pod replicas by creating new Pods alongside existing ones, balancing them across nodes.

❓ tradeoff

advanced

What is a tradeoff when using a single Pod with multiple containers versus multiple Pods with single containers?

Consider running multiple containers inside one Pod versus running each container in its own Pod. What is a key tradeoff?

A Single Pod containers cannot communicate internally; multiple Pods communicate via shared memory.

B Single Pod containers share resources closely but reduce isolation; multiple Pods increase isolation but add network overhead.

C Single Pod containers require separate IPs; multiple Pods share the same IP address.

D Single Pod containers have better network isolation; multiple Pods share storage more efficiently.

💡 Hint

Think about resource sharing and security boundaries.

Containers in the same Pod share network and storage, which is efficient but less isolated. Separate Pods provide better isolation but communicate over the network.

❓ estimation

expert

Estimate the number of Pods needed for a service expecting 10,000 requests per second with each Pod handling 500 requests per second.

You have a microservice deployed with Pods that can each handle 500 requests per second. To handle 10,000 requests per second reliably, how many Pods should you deploy?

A 20 Pods

B 15 Pods

C 25 Pods

D 10 Pods

💡 Hint

Divide total requests by capacity per Pod and consider no overloading.

To handle 10,000 requests per second with each Pod handling 500, you need 10,000 / 500 = 20 Pods.