Cloudflare

How to Fix 504 Gateway Timeout Error with Cloudflare

The 504 Gateway Timeout error in Cloudflare indicates a problem specific to your Cloudflare configuration or environment. This guide provides platform-specific solutions.

Common Causes in Cloudflare

• Origin server responding too slowly
• Database queries taking too long
• Cloudflare proxy timeout (100 seconds for Free plan, 600s for Enterprise)
• Origin server overloaded
• Network connectivity issues between Cloudflare and origin

Step-by-Step Solutions

Solution 1: Increase Origin Server Timeout

1. For Nginx, increase timeout in /etc/nginx/sites-available/your-site:
2. fastcgi_read_timeout 300; (for PHP-FPM)
3. proxy_read_timeout 300; (for reverse proxy)
4. For Apache, edit httpd.conf: Timeout 300
5. Reload web server: sudo systemctl reload nginx

Solution 2: Optimize Database Queries

1. Enable slow query log in MySQL: slow_query_log = 1, long_query_time = 2
2. Check /var/log/mysql/slow-query.log for slow queries
3. Add indexes to frequently queried columns
4. Use EXPLAIN to analyze query performance
5. Consider query caching or Redis

Solution 3: Temporarily Bypass Cloudflare

1. In Cloudflare DNS, change orange cloud to gray (DNS only)
2. Wait for DNS propagation (up to 5 minutes)
3. Test if site works without Cloudflare
4. If it works, the issue is origin server performance
5. Re-enable Cloudflare (orange cloud)

Solution 4: Enable Cloudflare Argo (Paid Feature)

1. Log into Cloudflare Dashboard
2. Go to Traffic → Argo
3. Enable Argo Smart Routing
4. This uses faster network paths to your origin
5. Note: This is a paid feature ($5/month + usage)

Solution 5: Implement Application-Level Caching

1. Use page caching (WordPress: WP Super Cache, W3 Total Cache)
2. Implement Redis or Memcached for object caching
3. Enable Cloudflare Page Rules for edge caching
4. Set appropriate Cache-Control headers
5. Cache API responses with short TTL

Prevention Tips

• Monitor Cloudflare error logs regularly
• Implement proper health checks and monitoring
• Keep Cloudflare and dependencies up to date
• Set up alerting for error rate increases
• Document your configuration changes
• Test configuration changes in staging first