HTTP/Web Too Many Requests

The HTTP 429 status code indicates the client has sent too many requests in a given amount of time (rate limiting). The server is temporarily refusing to process the request.

Common Causes

Exceeding the API's rate limit (requests per second/minute/hour).
A misconfigured or overly aggressive client application or script.
Distributed Denial of Service (DDoS) attack traffic or unintentional traffic spikes.

How to Fix

1 Implement Exponential Backoff

Retry the failed request after a progressively longer wait time. This is the standard, polite way to handle rate limits.

BASH

 $ // Pseudo-code for exponential backoff
let delay = 1000; // Start with 1 second
const maxDelay = 60000;

while (attempts < maxAttempts) {
  try {
    await makeRequest();
    break; // Success
  } catch (error) {
    if (error.status === 429) {
      await sleep(delay);
      delay = Math.min(delay * 2, maxDelay); // Double the delay
      attempts++;
    } else {
      throw error; // Re-throw non-429 errors
    }
  }
}

2 Check and Respect Rate Limit Headers

Inspect the HTTP response headers for rate limit information (e.g., Retry-After, X-RateLimit-*) and adjust your request timing accordingly.

BASH

 $ # Example using curl to check headers
curl -I https://api.example.com/endpoint

# Look for headers like:
# Retry-After: 120
# X-RateLimit-Limit: 1000
# X-RateLimit-Remaining: 23
# X-RateLimit-Reset: 1640995200

3 Optimize and Throttle Client Requests

Reduce request frequency by implementing client-side throttling, caching responses, or batching multiple operations into a single request where the API supports it.

BASH

 $ # Example using a simple token bucket algorithm in Python
import time

class RateLimiter:
    def __init__(self, rate, per):
        self.rate = rate
        self.per = per
        self.allowance = rate
        self.last_check = time.time()

    def can_call(self):
        current = time.time()
        time_passed = current - self.last_check
        self.last_check = current
        self.allowance += time_passed * (self.rate / self.per)
        if self.allowance > self.rate:
            self.allowance = self.rate
        if self.allowance < 1.0:
            return False
        else:
            self.allowance -= 1.0
            return True