Essential Microservices Concepts and Interview Questions Quiz

Explore core microservices architecture principles, communication methods, resilience strategies, and best practices. This quiz is designed to help professionals and learners gauge their understanding of microservices fundamentals and interview essentials.

1. Understanding Microservices Basics

   Which statement best describes a microservices architecture?

   1. A single, large codebase handles all business functions together.
   2. An application is divided into small, independent services, each focused on a single business capability.
   3. All modules of the application are deployed as plugins within a core server.
   4. A cloud-based service for storing large amounts of data.

   Explanation: The correct answer explains the core idea of microservices, where each service is responsible for a specific business capability and operates independently. The monolithic approach described in the second option is the opposite of microservices. The third option refers more to plugin-based designs, not true microservices. The last option describes cloud storage, not application architecture.

2. Advantages of Microservices

   What is a primary benefit of adopting a microservices approach?

   1. All code written in one programming language
   2. Single deployment unit for all services
   3. Complexity is eliminated entirely
   4. Independent scalability of services

   Explanation: Microservices allow each service to be scaled on its own, improving efficiency and resource use. A single deployment unit suggests a monolith, which limits scalability. Requiring one language does not match the flexibility of microservices, while architectural complexity often increases, not disappears, with microservices.

3. Comparing Monolith to Microservices

   In a monolithic application, what is a commonly seen limitation compared to microservices?

   1. Each component stores its own data
   2. Flexible choice of technology per service
   3. Services are deployed independently
   4. Tightly coupled components make scaling and updating harder

   Explanation: Monolithic applications suffer from tightly coupled parts, which makes scaling or updating individual features difficult. In contrast, microservices provide independence of deployment and technology, and often encourage service-owned, isolated data stores. The incorrect options instead describe microservice advantages.

4. Communication Patterns

   What is an example of synchronous communication between microservices?

   1. Writing to a shared database
   2. Asynchronous message queue
   3. REST API call
   4. Periodic batch file transfer

   Explanation: REST API calls are a common method of synchronous communication, meaning the client waits for the response. Shared databases are discouraged in microservices due to coupling. Batch file transfer is neither common nor synchronous, while message queues are used for asynchronous communication.

5. API Gateway Responsibilities

   Which function is typically performed by an API Gateway in a microservices environment?

   1. Managing internal database replication
   2. Compiling source code for all microservices
   3. Encrypting all files in storage
   4. Routing client requests to appropriate services

   Explanation: An API Gateway acts as the single entry point, handling routing, security, and other concerns for incoming requests. Database replication is managed by the database layer, not the API Gateway. Encrypting files is a storage responsibility, and compiling source code is a build process, not routing-related.

6. Service Discovery Approaches

   How can service discovery be achieved in a microservices landscape?

   1. Embedding connection details in frontend JavaScript
   2. Configuring all endpoints manually in application code
   3. Using tools like Consul for client-side discovery
   4. Storing service addresses in cookies

   Explanation: Service discovery tools such as Consul or Eureka help services locate each other dynamically, which is essential for scalability and flexibility. Manual endpoint configuration is error-prone and does not adapt well to changes. Cookies and frontend storage of addresses are insecure and unreliable for backend service discovery.

7. Circuit Breaker Pattern Purpose

   What problem does the circuit breaker pattern address in microservices?

   1. Preventing repeated failed calls to an unavailable service
   2. Managing schema migrations across databases
   3. Ensuring user sessions remain active indefinitely
   4. Reducing data stored in logs

   Explanation: The circuit breaker pattern helps prevent a system from overwhelming a failing service by temporarily blocking requests, increasing overall resilience. Schema migrations relate to database management, user sessions are unrelated to circuit breakers, and log storage is a separate concern.

8. Handling Data Consistency

   Which technique promotes data consistency across distributed microservices?

   1. Disabling persistence for all services
   2. Only using static configuration files for data
   3. Synchronizing all services with a single global transaction
   4. Saga pattern

   Explanation: The Saga pattern breaks down complex transactions into smaller, coordinated local transactions, enabling data consistency across services. Global transactions are hard to scale and go against microservices design. Disabling persistence means data is lost, and static config files do not help with transactional data.

9. Database Design in Microservices

   What is a recommended database practice in microservices architecture?

   1. All services share a single common database
   2. Each service owns and controls its own schema or database
   3. A global configuration file manages reads and writes
   4. Services write to each other’s tables for faster queries

   Explanation: To avoid tight coupling, each microservice should have its own database, ensuring autonomous management and scalability. Sharing databases or tables leads to difficulties in maintenance and data integrity. Configuration files manage settings, not transactional data.

10. Microservices Resilience

    Which method is commonly used to increase resilience in a microservices system?

    1. Permitting unlimited incoming traffic with no limits
    2. Storing all logs in local text files only
    3. Removing any error handling logic from the code
    4. Implementing retry policies with timeouts

    Explanation: Retry policies and timeouts help handle temporary failures and prevent cascading faults in distributed systems. Allowing unlimited traffic with no control can overload services. Relying only on local logs hinders visibility, and removing error handling reduces system reliability.