The History of HAProxy

For over 20 years, HAProxy has been one of the industry’s most successful open source projects. It’s been continuously tested and improved by a massive and active open source community. See how HAProxy evolved into an essential part of the world’s technology infrastructure.

HAProxy 1999

Zprox

  • Testing tool developed to gauge how an application would perform when facing lots of clients with 28 Kbps modems
HAProxy 2000

Zprox

  • Modified to include regex-based header rewriting, with a minimalistic config language.
  • Keywords introduced: listen, server
HAProxy 2001

HAProxy 1.0

  • Developed to offload traffic from hardware load balancers
HAProxy 2002

HAProxy 1.1

  • Simple round-robin scheduler
  • Simple health checks
  • Improved its logging capabilities
  • Cookie insertion
HAProxy 2003

HAProxy 1.2

  • IPv6 support on the client side
  • Replaced the wait-queue linked list with a rbtree
  • Introduced maxconn setting
  • Keywords introduced: except, forwardfor
HAProxy 2006

HAProxy 1.3

  • Elastic Binary Trees within the internal scheduler
  • TCP scripting
  • Explicit source port ranges
  • Interface binding
HAProxy 2009

HAProxy 1.4

  • RDP protocol support with server stickiness and user filtering
  • Client-side Keep-Alive
  • HTTP authentication support
  • ACL-based persistence
HAProxy 2010

HAProxy 1.5

  • SSL and compression
  • Data sampling
  • Server-side Keep-alive
  • DDoS protection
HAProxy 2015

HAProxy 1.6

  • Lua Scripting
  • Server-side connection multiplexing
  • Dynamic buffer allocation
  • Replaced Zlib with an in-house stateless implementation
HAProxy 2016

HAProxy 1.7

  • HAProxy Runtime API
  • Server hot reconfiguration
  • SPOE (Stream Processing Offload Engine)
  • Introduced content processing agents & multi-type certs
HAProxy 2017

HAProxy 1.8

  • Improved HAProxy Runtime API
  • Introduced multithreading
  • Dynamic Cookies
  • New MUX layer
HAProxy 2018

HAProxy 1.9

  • HTX – internal HTTP representation
  • End-to-End HTTP/2 (enabling gRPC)
  • Improved queue priority control
  • Improved the scalability of the multithreading feature
HAProxy 2019

HAProxy 2.0

  • Cloud-native theading and logging
  • HAProxy Kubernetes Ingress Controller
  • HAProxy Data Plane API
  • Prometheus exporter

HAProxy 2.1

  • Dynamic SSL Certificate Updates
  • FastCGI
  • Improved debugging
  • Native Protocol Tracing
HAProxy 2020

HAProxy 2.2

  • Fully Dynamic SSL Certificate Storage
  • Improved idle connection management
  • Native Response Generator
  • Health Check System Overhaul

HAProxy 2.3

  • Syslog Protocol (UDP/TCP)
  • OpenTracing (SPOE)
  • SSL/TLS Environments
  • Improved Cache
HAProxy 2021

HAProxy 2.4

  • HTTP/2 WebsocketsFIX & MQTT Protocols
  • Dynamic SSL Certificate Storage
  • Built-in OpenTracing
  • DNS TCP Resoultion

Today, HAProxy is the world’s fastest and most widely used software load balancer. It’s responsible for providing high availability, security, and observability to some of the world’s highest-trafficked websites. Explore our User Spotlight Series to learn how the world’s top architects and engineers chose to implement HAProxy within their application architectures.

User Spotlight Series