HAProxyQuick RefBeginner
Fix HAProxy '503 Service Unavailable' Backend Down
Diagnose and fix HAProxy 503 Service Unavailable errors caused by backend servers failing health checks, connection limits, or misconfigured routing.
4 min read
TroubleshootingNetworking
HAProxy Troubleshooting & Fix Guides
Common HAProxy errors, step-by-step fixes, and troubleshooting guides. Resolve issues quickly with practical solutions from experienced DevOps engineers.
Error Fixes & Troubleshooting
HAProxy Guides & Best Practices
HAProxyTutorialBeginnerFresh
HAProxy Stick Tables For Session Persistence And DDoS Rate Limiting
If you've been running HAProxy in production for any length of time, you've probably hit one of two problems: either your users keep losing their sessions...
8 min read
HAProxyQuick RefBeginnerFresh
HAProxy ACL-Based Routing For Blue-Green Deployments Without Downtime
Blue-green deployments are one of the cleanest ways to ship without waking anyone up at 3am. HAProxy makes this surprisingly straightforward with ACL-based...
5 min read
NginxTutorialBeginner
HAProxy Advanced: SSL Termination, SNI Routing, and mTLS
Advanced HAProxy SSL configuration — multi-domain SNI routing from a single frontend, mutual TLS (mTLS) for service-to-service authentication, certificate management, and OCSP stapling.
5 min read
NginxTutorialBeginner
HAProxy Configuration Guide: TCP/HTTP Load Balancing, Health Checks, and SSL
A comprehensive HAProxy configuration guide covering frontends, backends, balance algorithms, active health checks, SSL termination, ACLs, rate limiting, and the runtime socket API.
6 min read
NginxTutorialBeginner
HAProxy + Keepalived: Production HA Load Balancer Setup
Step-by-step guide to building a highly available load balancer pair with HAProxy and Keepalived — covering the full stack from VIP configuration to health checks, stats, and SSL termination.
5 min read
HAProxyTutorialBeginner
HAProxy Health Checks and Automatic Failover
Configure HAProxy health checks at TCP, HTTP, and application layers with automatic failover, backup servers, and alerting for production reliability.
7 min read
HAProxyTutorialBeginner
HAProxy SSL Termination: Offload TLS Without the Headache
Configure HAProxy SSL termination to offload TLS from backend servers, including certificate management, hardening, and SNI-based routing.
6 min read
HAProxyTutorialAdvanced
HAProxy Load Balancing: From Installation to Production
Configure HAProxy for HTTP and TCP load balancing — installation, frontends, backends, health checks, ACLs, SSL termination, and the stats dashboard.
24 min read
About HAProxy
Reliable, high-performance TCP/HTTP load balancer used by some of the world's highest-traffic websites. Provides advanced health checking, rate limiting, SSL termination, and connection management.
Frequently Asked Questions
What are common HAProxy errors?
Common HAProxy issues include configuration errors, connectivity problems, performance bottlenecks, and permission issues. Browse our troubleshooting guides above for step-by-step fixes.
How do I troubleshoot HAProxy?
Start by checking logs, verifying configuration, and testing connectivity. Our HAProxy troubleshooting guides walk through common scenarios with specific commands and solutions.
Where can I find HAProxy fix guides?
DevOpsil provides step-by-step HAProxy fix guides written by experienced DevOps engineers. Each guide includes root cause analysis, solution steps, and prevention tips.
Can't Find Your Fix?
Request a troubleshooting guide for your specific HAProxy issue. Our team writes new fix guides based on community requests.