Rate limiting in Node.js - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is rate limiting in web applications?

Rate limiting is a technique to control how many requests a user or client can make to a server in a given time. It helps prevent overload and abuse.

beginner

Name a popular Node.js middleware used for rate limiting.

express-rate-limit is a popular middleware for Node.js that helps easily add rate limiting to Express apps.

intermediate

How does rate limiting improve security and performance?

It stops too many requests from one user, which can protect against attacks like denial of service and reduce server overload, keeping the app fast and stable.

beginner

What is a common strategy to identify users for rate limiting?

Using the user's IP address is common to track how many requests they make and apply limits accordingly.

advanced

Explain the difference between fixed window and sliding window rate limiting.

Fixed window counts requests in fixed time blocks (like per minute). Sliding window tracks requests continuously over time, giving smoother limits.

What is the main purpose of rate limiting in Node.js apps?

A To speed up database queries

B To encrypt user data

C To control the number of requests from a user in a time period

D To improve UI design

Rate limiting controls how many requests a user can make to protect the server from overload.

Which Node.js middleware is commonly used for rate limiting in Express?

A express-rate-limit

B body-parser

C cors

D helmet

express-rate-limit is designed specifically to add rate limiting to Express apps.

What user information is often used to apply rate limits?

A User's favorite color

B IP address

C Browser version

D Screen resolution

IP address helps identify the source of requests to apply limits.

Which rate limiting strategy counts requests in fixed time blocks?

A Fixed window

B Sliding window

C Token bucket

D Leaky bucket

Fixed window counts requests in set time intervals, like per minute.

How does rate limiting help prevent denial of service attacks?

A By blocking all users

B By encrypting data

C By speeding up server hardware

D By limiting how many requests a user can send quickly

Rate limiting stops attackers from flooding the server with too many requests.

Describe how you would add rate limiting to a Node.js Express app using middleware.

Think about installing a package and configuring it with limits.

Explain the difference between fixed window and sliding window rate limiting and when you might use each.

Consider how time is measured and requests are counted.