Microservices Made Easy: 10 Must-Know Concepts for Java Programmers Quiz

1. Understanding Microservices Architecture

   Which statement best describes the microservices architecture style?

   1. A collection of small, independently deployable services that communicate over a network.
   2. A single, large application that handles all business logic in one codebase.
   3. A system where code is copied across multiple repositories for safety.
   4. An approach where all services share the same memory space.
   5. A model with tightly-coupled functions running as a group.

2. Shared Databases in Microservices

   Why is sharing a single database among multiple microservices generally considered a bad practice?

   1. It leads to tight coupling between services and potential data inconsistency.
   2. It ensures strong consistency at all times.
   3. It speeds up service deployment.
   4. It simplifies troubleshooting and debugging.
   5. It allows all services to bypass network communication.

3. Service Discovery Basic Concept

   How do microservices typically locate and communicate with each other in a dynamic environment?

   1. By using a Service Discovery mechanism that registers and tracks service locations.
   2. By hardcoding IP addresses in every service config file.
   3. By storing all service information in a single class.
   4. By relying on a random number generator to choose services.
   5. By using manual DNS edits for each deployment.

4. API Gateway Function

   What is the primary responsibility of an API Gateway in a microservices setup?

   1. To act as a single entry point that routes client requests to the appropriate microservice.
   2. To provide a development environment for microservices.
   3. To store all user credentials centrally.
   4. To implement every microservice’s business logic.
   5. To replicate data between databases.

5. Database Per Service Pattern

   In microservices architecture, what is the main benefit of following the 'Database per Service' pattern?

   1. Each service can manage its own data independently, reducing dependencies.
   2. All services instantly receive data updates from others.
   3. It allows services to run on outdated versions.
   4. It enables direct table sharing between all services.
   5. It prevents services from being stateless.

6. Event-driven Communication

   What does 'event-driven communication' between microservices typically involve?

   1. Publishing and subscribing to events so services can react asynchronously.
   2. Starting all services at the same time.
   3. Hardcoding method calls between different services.
   4. Saving log files instead of sending messages.
   5. Using only database triggers for messaging.

7. Fault Tolerance Pattern

   Which pattern is commonly used in microservices to prevent cascading failures when a downstream service is unavailable?

   1. Circuit breaker pattern, which stops requests to a failing service.
   2. Waterfall pattern, which speeds up request flow.
   3. Singleton pattern, which ensures one instance per service.
   4. Round-robin pattern, which cycles requests between services.
   5. Cryptic breaker, which encrypts all service messages.

8. Scaling Microservices

   What is a key advantage of deploying each microservice independently when scaling?

   1. You can increase resources only for the services that need more capacity.
   2. All services are required to scale at the same time.
   3. Deployment must be paused for all services.
   4. It decreases fault tolerance for each service.
   5. Scaling always requires manual code edits in all services.

9. Stateless Services

   Why is it recommended to make microservices stateless whenever possible?

   1. It allows any instance to handle requests without needing previous session information.
   2. It forces all data to be stored in-memory only.
   3. It guarantees faster database joins.
   4. It eliminates the need for any external storage.
   5. It means each service can store state in global variables.

10. Testing Microservices

    What is a typical challenge when testing microservices compared to monolithic applications?

    1. Coordinating interactions between multiple independent services can be complex.
    2. No debugging tools are available for microservices.
    3. All microservices are written in the same language.
    4. Testing is always done manually without automation.
    5. Microservices never need integration tests.