Rate Limiter for Clean Stack

What is Rate Limiting?

Rate limiting is a technique used to control the number of requests a user can make to a server within a specified time frame. It helps in managing server load, preventing abuse, and ensuring fair usage of resources.

Why is Rate Limiting Necessary?

1. Prevent Abuse: Protects against denial-of-service attacks and other malicious activities.
2. Resource Management: Ensures fair distribution of resources among users.
3. Performance Stability: Maintains consistent performance by preventing server overload.
4. Cost Control: Reduces costs associated with excessive resource usage.

Rate Limiter Architecture

Implementation Idea

The Rate Limiter in Clean Stack is designed with flexibility and efficiency in mind:

1. Abstraction: The core RateLimiter interface abstracts the rate limiting logic, allowing different rate limiting strategies to be used interchangeably.
2. Provider-Agnostic: By accepting a RateLimiterProvider as a parameter, the implementation supports various rate limiting strategies without changing the core logic.
3. Policy Management: The limiter implements a policy-based management system, allowing efficient configuration of rate limits.

Rate Limiter Provider as a Parameter

The RateLimiterProvider is passed as a parameter to the createRateLimiter function, offering several advantages:

1. Flexibility: Users can choose the most suitable rate limiting strategy for their needs.
2. Testability: It's easier to mock the rate limiter provider in unit tests.
3. Dependency Injection: This design follows the dependency injection principle, improving modularity and maintainability.

Significance of Rate Limit Policies

Rate limit policies are a powerful feature of this rate limiter implementation:

1. Efficient Traffic Management: Allows fine-grained control over traffic flow.
2. Customizable Limits: Supports different limits for different users or endpoints.
3. Consistency Management: Helps maintain consistent application performance. ::: Usage example:

await rateLimiter.isAllowedRateLimit('user:1');

Using the Rate Limiter with a REST API

To use this rate limiter with a REST API:

1. Create a Rate Limiter provider:

   import { RateLimiterProvider } from '../rate-limiter';
   
   export function getRateLimiterProvider(): RateLimiterProvider {
     return {
       set: async (key: string, value: string, ttl?: number) => {
         // Implement set logic here
       },
       get: async (key: string) => {
         // Return stored value
       },
     };
   }

2. Set up the rate limiter provider:

   import { getRateLimiterProvider } from './rateLimiterProvider';
   import { createRateLimiter } from './rateLimiter';
   
   const rateLimiterProvider = getRateLimiterProvider();
   const rateLimiter = createRateLimiter(rateLimiterProvider, { maxRequests: 100, duration: 3600 });

3. Use in API routes:

   app.get('/users/:id', async (req, res) => {
     const userId = req.params.id;
     const rateLimitKey = `user:${userId}`;
   
     // Apply rate limiting
     const isAllowed = await rateLimiter.isAllowedRateLimit(rateLimitKey);
     if (!isAllowed) {
       return res.status(429).send('Too Many Requests');
     }
   
     // Fetch user data
     const userData = await fetchUserFromDatabase(userId);
   
     res.json(userData);
   });

This implementation provides a flexible, efficient, and powerful rate limiting solution for Clean Stack, enhancing performance and scalability while maintaining ease of use and adaptability to different rate limiting strategies.