How to Force a Retry on Specific HTTP Status Codes in Your Application

How can I configure my application to automatically retry requests on specific HTTP status codes?

// Example using Axios in JavaScript
const axios = require('axios');

const instance = axios.create();

instance.interceptors.response.use(null, (error) => {
  const { response } = error;
  if (response) {
    if (response.status === 500 || response.status === 503) {
      return instance.request(error.config);
    }
  }
  return Promise.reject(error);
});

Automatically retrying HTTP requests based on specific statuses can significantly enhance your application's robustness by ensuring successful communication despite transient issues. This process involves intercepting responses and re-sending requests under defined conditions.

// Implementing a basic retry pattern with Axios
const maxRetries = 3;
const retryDelay = 1000; // in milliseconds

async function fetchWithRetry(url, retries = maxRetries) {
  try {
    const response = await axios.get(url);
    return response.data;
  } catch (error) {
    if (error.response && retries > 0 && (error.response.status === 500 || error.response.status === 503)) {
      await new Promise(res => setTimeout(res, retryDelay));
      return fetchWithRetry(url, retries - 1);
    }
    throw error;
  }
}

Causes

• Transient network issues
• Server overloads
• Temporary downtime of services

Solutions

• Use interceptors in HTTP clients like Axios or Fetch to catch errors and retry based on status codes.
• Implement a delay mechanism to prevent immediate retries, which can overwhelm the server.

Mistake: Not implementing exponential backoff strategies when retrying.

Solution: Incorporate a delay that increases each time the request fails.

Mistake: Retrying on client-side errors like 400 status codes.

Solution: Only retry on server-side errors to avoid unnecessary load.