Microservices Core Architectural Principles Questions and Answers

Question 1

Which of the following principles is most critical for ensuring that a failure in one microservice does not cascade and cause a system-wide outage?

Accepted Answer

Fault Tolerance and Isolation

Answer

Fault Tolerance and Isolation is the core principle designed to contain failures within a single service's boundary, preventing them from affecting other services. This is often achieved using patterns like circuit breakers, bulkheads, and timeouts to ensure the overall system remains resilient and available even when individual services fail.

Question 2

A development team is building an e-commerce platform using microservices. They decide that the 'User' service, 'Order' service, and 'Payment' service will all share a single, large relational database to simplify initial development. Which core microservice principle does this approach violate?

Accepted Answer

Decentralized Data Management

Answer

This approach directly violates the principle of Decentralized Data Management. A fundamental tenet of microservices is that each service should own its own data and database. Sharing a single database creates tight coupling between services; a change in the database schema for the 'Order' service could inadvertently break the 'User' or 'Payment' services, undermining their independence and autonomy.

Question 3

The Single Responsibility Principle (SRP) is applied to microservices by aligning each service with a specific business capability. This is most closely related to which concept from Domain-Driven Design (DDD)?

Accepted Answer

Bounded Context

Answer

A Bounded Context in Domain-Driven Design defines a specific boundary within which a particular domain model is consistent and well-defined. This maps directly to the goal of the Single Responsibility Principle in microservices, where each service encapsulates a distinct business capability or domain, ensuring high cohesion and clear boundaries.

Question 4

To maintain loose coupling and autonomy, how should microservices ideally communicate with each other when a direct, immediate response is not required?

Accepted Answer

Through asynchronous messaging via a message broker

Answer

Asynchronous messaging is the preferred communication pattern for maintaining loose coupling when an immediate response is not necessary. It decouples the sender from the receiver, meaning the services do not need to be available at the same time. This improves resilience and scalability, as a service can publish an event without waiting for the consumer to process it.

Question 5

What is the primary benefit of designing microservices to have 'high cohesion'?

Accepted Answer

It ensures that all related logic for a specific business capability is located within a single service.

Answer

High cohesion means that all the elements within a single service are tightly related and focused on a single, well-defined purpose. This ensures that when a change to a business capability is required, the modifications are likely to be contained within that one cohesive service, making the system easier to understand, maintain, and update.

Microservices Practice Test

Microservices Practice Test

Microservices Core Architectural Principles Questions and Answers