HAProxy Troubleshooting Guides

HAProxy errors can surface at the worst possible moments — during deployments, under peak traffic, or in the middle of critical operations. This collection of 3 troubleshooting guides covers the most common HAProxy issues encountered in network infrastructure, protocols, and connectivity. Each article walks through specific error messages with step-by-step diagnosis, root cause analysis, and verified solutions. Whether you're dealing with configuration problems, authentication failures, timeout errors, or unexpected behavior, these guides are designed to get you from error message to resolution as quickly as possible. Solutions are backed by official documentation and real-world production experience.

Error Quick Reference

Article	Description
Fixing HAProxy 503 Service Unavailable, 502 Bad Gateway & 504 Timeout Errors	Learn how to troubleshoot and fix HAProxy 503 Service Unavailable and 502/504 gateway errors. Step-by-step diagnostic guide for backend connection issues.
HAProxy 503 Service Unavailable: Complete Troubleshooting Guide	Fix HAProxy 503 Service Unavailable fast. Root causes: health checks, maxconn limits, no backend pool—plus step-by-step fixes with real commands.
Resolving HAProxy SSL Handshake Failure: A Complete Troubleshooting Guide	Fix HAProxy SSL handshake failures caused by cipher suite mismatches, missing intermediate certificates, SNI configuration errors, and backend verification issu