Microservices Basics for Mobile Backends Quiz

Explore essential concepts of microservices architecture as applied to mobile backend development. This quiz is designed to help learners and developers understand distributed systems, communication patterns, scalability, and fault tolerance in mobile application backends.

  1. Definition of Microservices

    Which statement best describes a microservices architecture in the context of mobile backend development?

    1. A frontend user interface combined with backend services in one application.
    2. A single large application that handles all business logic.
    3. A database-only solution for mobile apps.
    4. A collection of small, independently deployable services that communicate with each other.

    Explanation: Microservices architecture organizes an application as a collection of loosely coupled services that can be independently developed and deployed. This contrasts with a single large application, which is known as a monolith, making the second option incorrect. The third option confuses application layers, while the fourth option neglects essential service logic required for mobile backends. Only the first option accurately reflects microservices for mobile backends.

  2. Communication Patterns

    In a mobile backend built with microservices, which protocol is most often used for synchronous communication between services?

    1. HTTP/REST
    2. SMTP
    3. Bluetooth
    4. UDP Multicast

    Explanation: HTTP/REST is a common protocol for synchronous communication in microservices due to its widespread adoption and compatibility with most platforms. Bluetooth is used for short-range device-to-device communication and is not suitable for backend services. UDP Multicast is typically used for broadcasting to multiple hosts rather than direct service-to-service calls. SMTP is primarily used for email delivery, not microservices communication.

  3. Data Consistency

    How do microservices typically maintain data consistency across different services in a mobile backend?

    1. Locking all databases before transactions
    2. Storing all data in flat files
    3. Sharing a single database among all services
    4. Using eventual consistency across services

    Explanation: Microservices often use eventual consistency, where services update their own data stores and synchronize over time, since strict consistency can reduce scalability. Sharing one database reduces independence and can cause bottlenecks. Locking all databases before each transaction hurts performance and scalability. Using flat files is an outdated and unreliable method for modern distributed systems.

  4. Scaling Benefits

    Why is scaling individual services in a microservices-based mobile backend advantageous?

    1. It is less expensive than scaling monolithic applications in all cases.
    2. It always doubles the performance of the whole system.
    3. It requires every service to run on a separate device.
    4. It allows allocating resources based on specific service demand.

    Explanation: Scaling individual services means each service can have resources matched to its current needs, making resource utilization more efficient. The second option is incorrect because scaling does not guarantee doubled performance system-wide. The third option is incorrect, as services can run on virtualized or shared environments. The fourth option is not always true, since cost effectiveness depends on several factors.

  5. Service Discovery

    What is the main purpose of using a service discovery mechanism in a microservices mobile backend?

    1. To optimize wireless network bandwidth
    2. To encrypt data between mobile clients
    3. To monitor the temperature of servers
    4. To help services locate each other at runtime

    Explanation: Service discovery enables microservices to dynamically find the network locations of other services, which is important when services frequently scale up or down. The second option is related to security but not discovery. The third and fourth options are unrelated to locating services within a microservices system.

  6. Fault Tolerance

    In a microservices-based mobile backend, why is it important for each service to handle failures gracefully?

    1. Because all services share the same codebase.
    2. To accelerate the speed of frontend user interfaces.
    3. So that the failure of one service does not bring down the entire system.
    4. To eliminate the need for error logging.

    Explanation: One of the key benefits of microservices is resilience. If a single service fails, the rest of the system can continue operating, enhancing reliability. Speeding up user interfaces (option two) is unrelated to backend fault tolerance. Sharing codebases contradicts microservice principles (option three). Eliminating error logging (option four) is not a benefit but a risk.

  7. Independent Deployment

    How does independent deployment benefit microservices in mobile backends?

    1. Allows updates to one service without affecting others
    2. Forces all services to use identical programming languages
    3. Requires full system downtime for updates
    4. Prevents bug fixes from being introduced

    Explanation: With independent deployment, each service can be updated, fixed, or scaled individually, enhancing system flexibility and uptime. Requiring full system downtime (option two) is a characteristic of monolithic applications, not microservices. Option three is incorrect because microservices encourage language diversity. Option four is incorrect—independent deployment actually supports faster bug fixes.

  8. API Gateway Role

    What is the main function of an API gateway in a microservices architecture for mobile backends?

    1. Encrypts only database transactions inside each microservice
    2. Handles user authentication on the client-side only
    3. Monitors battery usage on mobile devices
    4. Acts as a single entry point for client requests and routes them to the appropriate services

    Explanation: An API gateway serves as a central access point for client requests, routing them to the correct services while offering features like load balancing. Monitoring device battery or handling database encryption isn't its role. User authentication is often included, but only on the backend, not exclusively on the client side.

  9. Decoupling Services

    Why is it recommended to keep microservices loosely coupled in a mobile backend architecture?

    1. To share the same user interface code among services
    2. To increase the memory usage of each service
    3. To minimize dependencies and make changes easier without impacting other services
    4. To use as few network calls as possible

    Explanation: Loosely coupled microservices have fewer dependencies, allowing each to evolve independently, which supports flexibility and scalability. Using few network calls is desirable but not a primary benefit of loose coupling. Sharing user interface code goes against backend separation. Option four is not accurate; loose coupling is unrelated to memory usage.

  10. State Management

    What is a common approach to managing state in microservices for mobile backends?

    1. State is ignored and only logs are kept
    2. Each service manages its own data and avoids direct shared state
    3. All services write to the same table in a global database
    4. State is kept in temporary cache only

    Explanation: Microservices promote autonomy by letting each service maintain its own state, which reduces complexity and potential conflicts. Sharing database tables hinders independence and scalability. Relying only on cache risks data loss. Ignoring state altogether is impractical for backend systems.