chore: Add API Rate limiting to API documentation

apps/www/content/glossary/api-rate-limiting.mdx

@@ -0,0 +1,150 @@
+---
+title: "API Rate Limiting: Best Practices Guide"
+description: Unlock API rate limiting power. Learn from real-world examples. Explore Cloudflare and REST API strategies.
+h1: "API Rate Limiting: Implementing Best Practices"
+term: API Rate Limiting
+categories: []
+takeaways:
+  tldr: API rate limiting is a technique to control the number of requests a client can make to an API within a specific timeframe, ensuring stability, performance, and security.
+  definitionAndStructure:
+    - key: Control Mechanism
+      value: Request Limit
+    - key: Purpose
+      value: Stability, Performance, Security
+    - key: Implementation
+      value: Token Bucket, Leaky Bucket, Fixed Window Counter, Sliding Window Counter, IP Throttling
+  historicalContext:
+    - key: Introduced
+      value: Est. ~2000s
+    - key: Origin
+      value: Web Services (API Rate limiting)
+    - key: Evolution
+      value: Standardized API Rate limiting
+  usageInAPIs:
+    tags:
+      - API
+      - Rate Limiting
+      - Security
+      - Performance
+    description: API rate limiting is used to prevent API abuse, protect against denial-of-service attacks, and ensure fair usage. It's implemented in APIs of major platforms like Facebook, Twitter, and Google Maps. Different methods like Token Bucket, Leaky Bucket, Fixed Window Counter, Sliding Window Counter, and IP Throttling are used based on the use case.
+  bestPractices:
+    - Assess API call frequency and user activity to set appropriate rate limits.
+    - Provide clear feedback on rate limit errors to inform users when they have exceeded the limit.
+    - Have contingency plans for when limits are breached to ensure continued service availability.
+  recommendedReading:
+    - url: https://www.example.com/api-rate-limiting
+      title: API Rate Limiting — Everything You Need to Know
+    - url: https://www.example.com/rate-limiting-best-practices
+      title: Best Practices and Configurations for Implementing Rate Limiting in APIs
+    - url: https://www.example.com/rate-limiting-guide
+      title: Everything You Need to Know About Rate Limiting for APIs
+  didYouKnow: API rate limiting not only protects against abuse but also helps in reducing operational costs by preventing unnecessary resource utilization.
+faq:
+  - answer: |-
+      Best practices for handling API rate limiting exceedance include: 
+      1. Defining a clear rate limiting strategy that balances user needs and system resources. 
+      2. Identifying clients using unique identifiers such as API keys or IP addresses. 
+      3. Implementing rate limiting logic, typically through middleware in your API management system. 
+      4. Handling rate limit exceedances gracefully, by returning informative error messages that indicate when the client can retry. 
+      5. Resetting rate limits at appropriate intervals, such as every hour or day. 
+      6. Logging and monitoring rate limit usage to identify potential issues or abuses. 
+      7. Informing clients about their rate limit status in HTTP headers. 
+      8. Regularly testing and iterating on your rate limiting strategy to ensure it meets evolving needs.
+    question: What are the best practices for API rate limiting exceedance?
+  - answer: The best way to implement rate limiting depends on your specific needs, but a common approach is to use a token bucket or leaky bucket algorithm. These algorithms allow a certain number of requests per time period, and either accumulate 'tokens' for unused requests (token bucket) or 'leak' excess requests over time (leaky bucket). If a client exceeds their limit, their requests are either denied or delayed until they have sufficient tokens or their bucket has leaked enough. This can be implemented at the application level, or using a dedicated API management system or gateway.
+    question: What is the best way to implement rate limiting?
+  - answer: API rate limiting is typically implemented using middleware in an API management system or gateway. This middleware checks each incoming request against the client's rate limit, which is typically defined in terms of a maximum number of requests per time period. The client's usage is tracked using a unique identifier such as an API key or IP address. If the client exceeds their limit, the middleware can deny the request and return an error message, or delay the request until the rate limit is reset. The rate limit and current usage can also be communicated to the client in HTTP headers.
+    question: How is API rate limiting implemented?
+  - answer: When dealing with an API that rate limits requests, it's important to handle potential rate limit exceedances gracefully. This means checking the HTTP headers for rate limit information, and if a rate limit error is received, waiting the appropriate amount of time before retrying. It's also a good idea to implement a backoff strategy, where the time between retries increases if multiple rate limit errors are received. Finally, consider optimizing your API usage to reduce the number of requests, such as by caching results or using bulk operations where available.
+    question: How to deal with API that rate limits requests?
+updatedAt: 2024-11-25T19:00:38.000Z
+slug: api-rate-limiting
+---
+
+API rate limiting is a critical component in API management that helps control the rate at which user applications can make requests to API endpoints. This is essential to prevent abuse, manage the load on the API server, and ensure fair usage among consumers. In this guide, we will explore various aspects of **API rate limiting**, including best practices, implementation strategies, and resources for developers.
+
+## Understanding API Rate Limiting Concepts
+
+API rate limiting involves restricting the number of API calls a user or service can make within a specified time period. Key concepts include:
+
+- **Rate Limit**: The maximum number of requests a client can make in a defined time period.
+- **Throttle**: Temporarily limiting the access of users who exceed the rate limit.
+- **Quota**: The total number of allowed requests in a longer time period (e.g., a day or a month).
+- **Burst Limits**: Allows for short bursts of calls, often used to handle usage spikes smoothly.
+
+## Best Practices for API Rate Limiting
+
+Implementing effective **API rate limiting best practices** is crucial for maintaining API performance and user satisfaction. Here are some recommended strategies:
+
+1. **Transparent Policies**: Clearly communicate rate limits to API consumers to avoid confusion and frustration.
+2. **Dynamic Limits**: Adjust rate limits based on server load and user behavior to optimize performance.
+3. **High Availability**: Implement failover strategies to ensure limit enforcement when primary systems fail.
+4. **Graceful Degradation**: Instead of hard stopping, provide users with limited functionality or degraded service when they hit limits.
+5. **Feedback Mechanisms**: Use HTTP headers to provide real-time usage data back to the user.
+
+## Implementing API Rate Limiting: Examples
+
+Here’s a practical example of implementing **API rate limiting** in Python using Flask and Redis:
+
+```python
+# Python example using Flask and Redis to implement rate limiting
+from flask import Flask, request, jsonify
+import redis
+from functools import wraps
+
+app = Flask(__name__)
+redis_client = redis.StrictRedis(host='localhost', port=6379, db=0)
+
+def rate_limiter(max_requests, time_period):
+    def decorator(f):
+        @wraps(f)
+        def decorated_function(*args, **kwargs):
+            key = f"{request.remote_addr}:{request.endpoint}"
+            try:
+                requests = int(redis_client.get(key) or 0)
+            except redis.RedisError:
+                return jsonify({"error": "Redis server is not responding"}), 503
+
+            if requests >= max_requests:
+                return jsonify({"error": "Rate limit exceeded"}), 429
+
+            redis_client.incr(key, 1)
+            redis_client.expire(key, time_period)
+            return f(*args, **kwargs)
+        return decorated_function
+    return decorator
+
+@app.route('/api/resource')
+@rate_limiter(max_requests=100, time_period=60)
+def my_api_endpoint():
+    return jsonify({"success": "Access granted"})
+
+if __name__ == "__main__":
+    app.run()
+```
+
+## GitHub Resources for API Rate Limiting
+
+For developers looking to implement **API rate limiting best practices and implementation**, here are some useful GitHub resources:
+
+1. **ratelimit**: A Python library that offers simple and efficient rate-limiting using decorators.
+2. **express-rate-limit**: A Node.js rate limiting middleware for Express applications.
+3. **go-rate**: A Golang limiter for managing access frequency to resources.
+
+## Cloudflare Rate Limiting Strategies
+
+Cloudflare provides advanced **rate limiting best practices** that protect APIs by identifying and mitigating excessive request rates. Strategies include:
+
+- **Geo-targeting**: Different limits for different regions.
+- **Anomaly Detection**: Automatically adjusting limits based on traffic patterns.
+- **Custom Responses**: Tailoring responses based on the type of rate limit trigger.
+
+## REST API Rate Limiting Techniques
+
+REST APIs can implement rate limiting using several techniques, which are essential for maintaining performance and user experience:
+
+- **HTTP Headers**: Communicate limits and current usage to clients (`X-RateLimit-Limit`, `X-RateLimit-Remaining`).
+- **Retry-After**: Use this header to inform clients when to retry after hitting a rate limit.
+- **Token Bucket Algorithm**: A flexible method for rate limiting that allows for bursts of requests.
+
+By understanding and implementing these **API rate limiting best practices and implementation** strategies, API developers can ensure their APIs remain robust, fair, and scalable. For further reading, consider exploring resources on **OWASP rate limiting best practices** and **Cloudflare rate limiting best practices** to enhance your API management skills.