REST API Gateways, Reverse Proxies, and Load Balancers Essentials Quiz Quiz

Explore fundamental concepts of REST API gateways, reverse proxies, and load balancers with this quiz designed to reinforce understanding of core functions, benefits, and differences between these crucial networking components.

1. API Gateway Function

   Which primary function does an API gateway perform in a microservices architecture?

   1. It ensures direct client-to-database communication.
   2. It replaces all load balancers in the network.
   3. It routes client requests to appropriate backend services.
   4. It encrypts all data stored on the backend servers.

   Explanation: API gateways primarily route client requests to the correct backend services, often handling tasks like authentication and aggregation. Encrypting backend data is generally a function of security modules, not gateways. Allowing clients unfettered access to databases bypasses proper API design, and while an API gateway may perform some load distribution, it does not universally replace load balancers.

2. Reverse Proxy Role

   In a typical web application, what is the main purpose of deploying a reverse proxy?

   1. To forward client requests to backend servers while hiding their internal structure.
   2. To store data directly for users and handle long-term file storage.
   3. To establish new network cables between servers.
   4. To provide user authentication without contacting any backend systems.

   Explanation: A reverse proxy acts as an intermediary, forwarding client requests to backend servers and concealing their internal details. It does not act as a storage device or handle physical infrastructure changes like cabling. While a reverse proxy can help with authentication, it does not typically provide authentication without backend interaction.

3. Load Balancer Purpose

   What is the main reason for using a load balancer in a network serving a high volume of web traffic?

   1. To evenly distribute incoming traffic across multiple servers.
   2. To assign static IP addresses to client devices.
   3. To increase the speed of internal graphics processing.
   4. To directly encrypt all outgoing emails from the server.

   Explanation: A load balancer distributes incoming network traffic to different servers to enhance performance and reliability. Encrypting emails and assigning IP addresses are unrelated to load balancing, and internal graphics processing is not connected to web traffic management.

4. API Gateway vs Reverse Proxy

   How does an API gateway typically differ from a standard reverse proxy?

   1. An API gateway sends emails to backend servers, but reverse proxies do not.
   2. An API gateway can manage authentication and rate limiting, while a reverse proxy usually only forwards requests.
   3. A reverse proxy always encrypts client communications, while an API gateway does not.
   4. A reverse proxy stores data permanently, but an API gateway deletes it.

   Explanation: API gateways often include advanced features like authentication, rate limiting, and request transformation, while reverse proxies mainly forward requests. Neither component is dedicated to emailing or data storage, and encryption is generally handled elsewhere in the network stack.

5. Health Checks in Networking

   Why do load balancers frequently perform health checks on backend servers?

   1. To send advertisement banners to users.
   2. To ensure that traffic is only sent to healthy and available servers.
   3. To permanently store sensitive business data.
   4. To configure firewalls on client devices.

   Explanation: Load balancers use health checks to avoid routing traffic to servers that are offline or malfunctioning. Storing business data and configuring client firewalls are outside the scope of load balancing, and advertising delivery has no direct relation to this process.

6. SSL Termination Placement

   Where is SSL termination commonly handled when using a load balancer or reverse proxy setup?

   1. Exclusively on the client’s local device.
   2. Only inside the application code running on backend servers.
   3. At the load balancer or reverse proxy before forwarding plain traffic to backend servers.
   4. Within the database engine during data reads.

   Explanation: SSL termination is often performed at the load balancer or reverse proxy, which decrypts client traffic before passing it internally. Clients do not perform termination for the entire network, and backend application code or databases are not responsible for initial SSL termination.

7. Sticky Sessions Usage

   Which scenario typically requires enabling sticky sessions on a load balancer?

   1. When all sessions should avoid single-server use.
   2. When images need to be compressed for faster delivery.
   3. When each client must access a different database.
   4. When a user’s requests need to go to the same backend server during a session.

   Explanation: Sticky sessions bind a user’s requests to a specific server during their session, often needed when temporary data is stored locally on the server. They are unrelated to database selection or image compression, and avoiding single-server use is the opposite of enabling sticky sessions.

8. Rate Limiting Implementation

   Where is rate limiting most commonly enforced in a RESTful system for protecting backend services?

   1. Individually by database engines, after data is served.
   2. At the API gateway, before requests reach backend services.
   3. In the operating system kernel of client devices.
   4. By the email sending server process.

   Explanation: API gateways often manage rate limiting to prevent abuse, stopping excessive requests before reaching backend servers. Databases and OS kernels are generally not involved in request rate limits for APIs, and email servers are unrelated to this process.

9. Caching and Traffic Efficiency

   How does adding a reverse proxy with caching capabilities improve web service performance?

   1. By encrypting all static files on every response.
   2. By only allowing administrative users to connect.
   3. By constantly creating new server instances for every request.
   4. By serving repeated requests from cache and reducing backend load.

   Explanation: A reverse proxy with caching can serve repeat requests directly, reducing the number of times backend servers must process the same data. It does not create new servers, handle encryption for every response, or restrict access to administrators by default.

10. Load Balancing Algorithms

    When a load balancer uses the round-robin algorithm, how are requests distributed?

    1. Requests are sent to each backend server in a repeating, sequential order.
    2. Requests are always sent to the server with the lowest IP address.
    3. Requests are sent randomly with no pattern.
    4. Requests are sent only to servers with the longest queue.

    Explanation: The round-robin algorithm distributes requests sequentially and evenly to each backend, cycling through them. Random dispatching and prioritizing based on queue length are different methods, while IP address-based allocation is not typical for round-robin.