Services and networking in Microservices - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Architecture

intermediate

Designing Service Communication in Microservices

You have three microservices: User, Order, and Inventory. Which communication pattern best reduces tight coupling and improves scalability?

A Using an asynchronous message broker for event-driven communication

B Synchronous HTTP calls directly between services for every request

C Embedding all logic into a single monolithic service

D Using shared database tables for communication between services

💡 Hint

Think about how services can work independently without waiting on each other.

Asynchronous message brokers allow services to communicate without waiting, reducing tight coupling and improving scalability.

❓ scaling

intermediate

Scaling Service Discovery in a Microservices Environment

You have 100 microservices instances running across multiple servers. Which approach best supports automatic service discovery and load balancing?

A Manually configure IP addresses of all instances in each service

B Use a centralized service registry with health checks and client-side load balancing

C Use DNS with static entries for each service instance

D Hardcode service endpoints in configuration files

💡 Hint

Consider how services can find healthy instances dynamically without manual updates.

A centralized service registry with health checks allows services to discover healthy instances dynamically and balance load efficiently.

❓ tradeoff

advanced

Choosing Between API Gateway and Service Mesh

Which statement best describes a key tradeoff when choosing between an API Gateway and a Service Mesh for microservices networking?

A API Gateway centralizes external client requests, while Service Mesh manages internal service-to-service communication with fine-grained control

B API Gateway handles internal service-to-service communication, while Service Mesh manages external client requests

C API Gateway and Service Mesh are identical and interchangeable in all scenarios

D Service Mesh replaces the need for load balancers, while API Gateway replaces the need for service discovery

💡 Hint

Think about the roles of API Gateway and Service Mesh in handling traffic.

API Gateway centralizes external client requests, providing routing and security, while Service Mesh manages internal service communication with features like retries and observability.

🧠 Conceptual

advanced

Understanding Circuit Breaker Pattern in Microservices

What is the primary purpose of the circuit breaker pattern in microservices networking?

A To encrypt all network traffic between services

B To route requests to the nearest service instance geographically

C To automatically scale services based on load

D To prevent a service from repeatedly calling a failing service and causing cascading failures

💡 Hint

Consider how to protect the system when one service is down or slow.

The circuit breaker stops calls to a failing service temporarily to avoid cascading failures and improve system resilience.

❓ estimation

expert

Estimating Network Bandwidth for Microservices Communication

You have 50 microservices instances communicating via REST APIs. Each instance sends 100 requests per second, each request is 2KB, and the response is 3KB. Estimate the total network bandwidth required in Mbps.

A 80 Mbps

B 100 Mbps

C 160 Mbps

D 120 Mbps

💡 Hint

Calculate total data per second and convert bytes to bits, then to Mbps.

Total requests per second = 50 instances * 100 = 5000 requests/sec. Each request + response = 2KB + 3KB = 5KB = 5120 bytes. Total bytes per second = 5000 * 5120 = 25,600,000 bytes/sec. Convert to bits: 25,600,000 * 8 = 204,800,000 bits/sec = 204.8 Mbps. Since options are lower, closest lower option is 160 Mbps (rounded estimate).