Knowledge Base
Welcome to HAProxy’s extensive and ever-expanding knowledge base. Created by a team of experts including HAProxy’s Core Development Team; it covers a wide range of topics to help you achieve maximum potential.
Rate Limiting with the HAProxy Kubernetes Ingress Controller
Add IP-by-IP rate limiting to the HAProxy Kubernetes Ingress Controller. DDoS (distributed denial of service) events occur when an attacker or group of attackers flood your application or API with disruptive traffic, hoping to exhaust its resources and prevent...
September/2021 – CVE-2021-40346: Duplicate ‘Content-Length’ Header Fixed
If you are using HAProxy 2.0 or newer, it is important that you update to the latest version. A vulnerability was found that makes it possible for an attacker to bypass the check for a duplicate HTTP Content-Length header, permitting a request smuggling attack or a...
August/2021 – HAProxy 2.0+ HTTP/2 Vulnerabilities Fixed
A vulnerability was found that makes it possible to abuse the HTTP/2 parser, allowing an attacker to prepend hostnames to a request, append top-level domains to an existing domain, and inject invalid characters through the :method pseudo-header.
[On-Demand Webinar] Multilayered Security with HAProxy Enterprise
Did you know that an HAProxy Enterprise load balancer can protect your applications from common threats? In this webinar, we'll give you an overview of the multilayered security solution provided by HAProxy Enterprise. We will cover how to: use the HAProxy...
Load Balancing/Routing
How to Enable Health Checks in HAProxy
HAProxy provides active, passive, and agent health checks. HAProxy makes your web applications highly available by spreading requests across a pool of backend servers. If one or even several servers fail, clients can still use your app as long as there are...
Rate Limiting with the HAProxy Kubernetes Ingress Controller
Add IP-by-IP rate limiting to the HAProxy Kubernetes Ingress Controller. DDoS (distributed denial of service) events occur when an attacker or group of attackers flood your application or API with disruptive traffic, hoping to exhaust its resources and prevent...
Testing Your HAProxy Configuration
Learn how to test your HAProxy Configuration. Properly testing your HAProxy configuration file is a simple, yet crucial part of administering your load balancer. Remembering to run one simple command after making a change to your configuration file can save you from...
The HAProxy APIs
The HAProxy load balancer provides a set of APIs for configuring it programmatically. Although many people enjoy the simplicity of configuring their HAProxy load balancer by directly editing its configuration file, /etc/haproxy/haproxy.cfg, others want a way to...
SSL
Announcing HAProxy Data Plane API 2.2
The HAProxy Data Plane API 2.2 lays the foundation for first-class service discovery and introduces native support for Consul. It also adds storage and file handling for SSL certificates, Map files, and SPOE configuration files. Watch our on-demand webinar "What’s New...
Route SSH Connections with HAProxy
Route SSH connections through HAProxy using the SSH ProxyCommand feature and SNI. Watch our on-demand webinar in French "How to Route SSH Connections with HAProxy". Did you know that you can proxy SSH connections through HAProxy and route based on hostname? The...
[On-demand Webinar] Achieving FIPS 140-2 Encryption Compliance with HAProxy Enterprise on Red Hat Enterprise Linux
Encryption is an important facet of cybersecurity. It involves scrambling messages so that they can not be read by unauthorized parties in order to protect private information, which is particularly important when sending data across an untrusted network or the...
Redirect HTTP to HTTPS with HAProxy
Use the HAProxy load balancer to redirect users from HTTP to HTTPS automatically. For decades, our lives have become increasingly dependent on sending and receiving data from across the Internet. Now, with more people working, studying, and hanging with friends...
Microservices
Consul Service Discovery for HAProxy
HAProxy with the HAProxy Data Plane API can integrate with Consul to enable service discovery for your load balancer configuration. Many Ops team professionals rank HAProxy as their favorite load balancer because it adds high availability, security and...
Power Your Consul Service Mesh with HAProxy
Many of you use HashiCorp Consul for service discovery. It makes connecting one backend application or service to another easy: Your Consul servers store a catalog of addresses to all of your services; when an application within the network wants to discover where a...
Circuit Breaking in HAProxy
With HAProxy, you can implement a circuit breaker to protect services from widespread failure. Martin Fowler, who is famous for being one of the Gang of Four authors who wrote Design Patterns: Elements of Reusable Object-Oriented Software, hosts a website where...
Accelerate Your APIs by Using the HAProxy Cache
HAProxy's cache helps boost API performance by serving saved messages to your users. The age of rendering most of a web page's contents on the server and then delivering it as a colossal HTML file is fading into the past. Modern web frameworks like Angular, React, and...
Performance
Autoscaling with the HAProxy Kubernetes Ingress Controller and KEDA
This blog post describes how to implement autoscaling of your application pods using KEDA and the HAProxy Kubernetes Ingress Controller. Since it was published, a new feature has been added to the ingress controller that lets you autoscale the number of ingress...
Protect Servers with HAProxy Connection Limits and Queues
HAProxy connection limits and queues can help protect your servers and boost throughput when load balancing heavy amounts of traffic. When you use HAProxy as an API gateway in front of your services, it has the ability to protect those servers from traffic...
Announcing HAProxy Kubernetes Ingress Controller 1.5
We've released version 1.5 of the HAProxy Kubernetes Ingress Controller. This version unlocks access to the raw HAProxy configuration language for power users to gain more control. You can also enable mutual TLS authentication between the ingress controller and...
HTTP Keep-Alive, Pipelining, Multiplexing and Connection Pooling
Persistent connections allow HAProxy to optimize resource usage, lower latency on both the client and server side, and support connection pooling. HTTP is a layer 7 protocol that's transmitted over a TCP connection. It works in a client-server model and follows...
Webinars
[On-Demand Webinar] Run the HAProxy Kubernetes Ingress Controller in External Mode
If you prefer to watch the French version of this webinar, register here. Traditionally, connecting clients to services in Kubernetes has required multiple layers of proxies. For example, an external load balancer will route traffic to your nodes. Then, kube-proxy...
[On-Demand Webinar] What’s New in the HAProxy Data Plane API 2.3
The HAProxy Data Plane API enables remote, dynamic configuration of your HAProxy load balancers. Version 2.3 of the API adds: service discovery for AWS EC2 instances and Auto Scaling groups, the ability to view, add, and remove HAProxy ACLs, support for forwarding API...
[On-Demand Webinar] Multilayered Security with HAProxy Enterprise
Did you know that an HAProxy Enterprise load balancer can protect your applications from common threats? In this webinar, we'll give you an overview of the multilayered security solution provided by HAProxy Enterprise. We will cover how to: use the HAProxy...
[On-Demand Webinar] HAProxy and the Financial Information eXchange (FIX) Protocol
If you prefer to join the French version of the webinar on May 25th, register here. HAProxy 2.4 and HAProxy Enterprise 2.3 add support for the Financial Information eXchange (FIX) protocol. Financial organizations around the world use FIX as a shared vocabulary for...
Basics
How to Enable Health Checks in HAProxy
HAProxy provides active, passive, and agent health checks. HAProxy makes your web applications highly available by spreading requests across a pool of backend servers. If one or even several servers fail, clients can still use your app as long as there are...
Testing Your HAProxy Configuration
Learn how to test your HAProxy Configuration. Properly testing your HAProxy configuration file is a simple, yet crucial part of administering your load balancer. Remembering to run one simple command after making a change to your configuration file can save you from...
Install HAProxy on Ubuntu
Learn how to Install HAProxy on Ubuntu 20.04. Ubuntu 20.04 is a great choice for installing your HAProxy software load balancer. It's a free Linux operating system that's fast, secure, and best of all, it's easy to use. One of the features that makes Ubuntu so...
How to Run HAProxy with Docker
Can you run HAProxy as a Docker container? Yes! Did you even need to ask? Docker is ubiquitous these days and you'll find that many applications have been Docker-ized; the HAProxy load balancer is no exception. Pardon the cliché, but HAProxy was born for this....
Benchmarking
HAProxy Forwards Over 2 Million HTTP Requests per Second on a Single Arm-based AWS Graviton2 Instance
For the first time, a software load balancer exceeds 2-million RPS on a single Arm instance. A few weeks ago, while I was working on an HAProxy issue related to thread locking contention, I found myself running some tests on a server with an 8-core, 16-thread...
Test Driving “Power of Two Random Choices” Load Balancing
The Power of Two Random Choices load-balancing algorithm has piqued some curiosity. In this blog post, we see how it stacks up against other modern-day algorithms available in HAProxy. Recently, I was asked twice about my opinion on supporting an algorithm known as...
Hypervisors Virtual Network Performance Comparison from a Virtualized Load Balancer Point of View
Introduction At HAProxy Technologies, we edit and sell a Load-Balancer appliance called ALOHA (stands for Application Layer Optimisation and High-Availability). A few month ago, we managed to make it run on the most common hypervisors available: VMWare (ESX, vsphere)...
Benchmarking SSL Performance
Introduction The story Recently, there has been some attacks against website which aimed to steal user identity. In order to protect their users, major website owners had to find a solution. Unfortunately, we know that sometimes, improving security means downgrading...
Random Tips
Serve Dynamic Custom Error Pages with HAProxy
Set up custom error pages in HAProxy to ensure consistent, branded messaging that supports any backend web stack. The memory is probably still fresh: You're shopping online at your favorite website, looking for something specific, you've got it narrowed down to two or...
[Conference Presentation] Dynamic Application Routing Over SSL with HAProxy Enterprise
Back in May, HAProxy Senior Systems Engineer Chad Lavoie presented at the OpenStack Summit Boston. Chad presented on using maps in HAProxy to dynamically route requests while securing your site with SSL combined with the use of the Update Module (included in HAProxy...
HAProxy and HTTP Errors 408 in Chrome
Lately, there was some discussions on HAProxy's mailing list about 408 errors printed in Chrome browsers. Origin of 408 errors 408 is the status code used by web servers or proxies when the client has not sent a whole HTTP request during a certain period of time. It...
Configure syslog-ng to Log Readable HTTP URL from HAProxy
These tips are provided by Exosec. Exosec provides a very good monitoring product called POM, based on Nagios with very strong value added such as very simple administration, application monitoring, etc... For some of their project, they use either HAProxy or the...
Observability
Visualize HAProxy Metrics with InfluxDB
HAProxy generates over a hundred metrics to give you a nearly real-time view of the state of your load balancers and the services they proxy, but to get the most from this data, you need a way to visualize it. InfluxData’s InfluxDB suite of applications takes...
Logging with the HAProxy Kubernetes Ingress Controller
The HAProxy Kubernetes Ingress Controller publishes two sets of logs: the ingress controller logs and the HAProxy access logs. After you install the HAProxy Kubernetes Ingress Controller, logging jumps to mind as one of the first features to configure. Logs...
Using HAProxy as an API Gateway, Part 4 [Metrics]
HAProxy publishes more than 100 metrics about the traffic flowing through it. When you use HAProxy as an API gateway, these give you insight into how clients are accessing your APIs. Several metrics come to mind as particularly useful, since they can help you...
HAProxy Log Sampling
Log Sampling is a powerful feature introduced in HAProxy 2.0 that lets you define a percentage of your logs to create a representative view of your data allowing you to minimize your costs. Log files are the key to observability. They can provide helpful information...
DevOps
The HAProxy APIs
The HAProxy load balancer provides a set of APIs for configuring it programmatically. Although many people enjoy the simplicity of configuring their HAProxy load balancer by directly editing its configuration file, /etc/haproxy/haproxy.cfg, others want a way to...
[On-Demand Webinar] HAProxy Skills Lab: Diagnosing Simple Problems
If you prefer joining the same webinar in French, register here. Troubleshooting network issues can seem like an arcane art. Operations teams build up knowledge through trial-and-error, online forums, and wisdom handed down from one generation to another. However, the...
[On-Demand Webinar] Learn the HAProxy Data Plane API 2.0
People know HAProxy as the high-performance software load balancer that they can configure once, then trust to do the job, but it's also the best choice for dynamic environments where change is constant. For instance, HAProxy's configuration can be generated on the...
Announcing HAProxy Data Plane API 2.0
Find out more by registering for our webinar: “Learn the HAProxy Data Plane API 2.0“ Version 2.0 of the HAProxy Data Plane API brings some exciting enhancements that unlock the power of HAProxy's flexible configuration and its runtime capabilities. The HAProxy Data...
Kubernetes
Rate Limiting with the HAProxy Kubernetes Ingress Controller
Add IP-by-IP rate limiting to the HAProxy Kubernetes Ingress Controller. DDoS (distributed denial of service) events occur when an attacker or group of attackers flood your application or API with disruptive traffic, hoping to exhaust its resources and prevent...
[On-Demand Webinar] Run the HAProxy Kubernetes Ingress Controller in External Mode
If you prefer to watch the French version of this webinar, register here. Traditionally, connecting clients to services in Kubernetes has required multiple layers of proxies. For example, an external load balancer will route traffic to your nodes. Then, kube-proxy...
Run the HAProxy Kubernetes Ingress Controller Outside of Your Kubernetes Cluster
Run your HAProxy Kubernetes Ingress Controller in External mode to reduce network hops and latency. Join our webinar to learn more about running the ingress controller in external mode. Traditionally, you would run the HAProxy Kubernetes Ingress Controller as a pod...
Announcing HAProxy Kubernetes Ingress Controller 1.6
We're proud to announce the release version 1.6 of the HAProxy Kubernetes Ingress Controller. This version provides the ability to add raw configuration snippets to HAProxy frontends, allows for ACL/Map files to be managed through a ConfigMap, and enables complex...
Service Discovery
[On-Demand Webinar] What’s New in the HAProxy Data Plane API 2.3
The HAProxy Data Plane API enables remote, dynamic configuration of your HAProxy load balancers. Version 2.3 of the API adds: service discovery for AWS EC2 instances and Auto Scaling groups, the ability to view, add, and remove HAProxy ACLs, support for forwarding API...
Consul Service Discovery for HAProxy
HAProxy with the HAProxy Data Plane API can integrate with Consul to enable service discovery for your load balancer configuration. Many Ops team professionals rank HAProxy as their favorite load balancer because it adds high availability, security and...
Announcing HAProxy Data Plane API 2.3
The HAProxy Data Plane API 2.3 expands its service discovery mechanisms and introduces native support for discovering AWS EC2 instances and auto-scaling groups. It also adds a new configuration file that supports HCL and YAML, an Inotify configuration watcher, and...
Power Your Consul Service Mesh with HAProxy
Many of you use HashiCorp Consul for service discovery. It makes connecting one backend application or service to another easy: Your Consul servers store a catalog of addresses to all of your services; when an application within the network wants to discover where a...
Cloud
AWS EC2 Service Discovery with HAProxy
AWS Auto Scaling groups are a powerful tool for creating scaling plans for your application. They let you dynamically create a group of EC2 instances that will maintain a consistent and predictable level of service. HAProxy's Data Plane API adds a cloud-native method...
HAProxy Enterprise Offers SAML-based Single Sign-on
HAProxy Enterprise handles SAML single sign-on for your applications and integrates with identity providers like Azure Active Directory. Single sign-on (SSO) is such a familiar convenience for companies that it's easy to forget how powerful it is. When employees...
Building Blocks of a Modern Proxy
A major outcome of IT/Ops evolution is realizing the importance of a reverse proxy, such as HAProxy, in achieving modern application delivery. This is the first post in a series about HAProxy's role in building a modern systems architecture that relies on cloud-native...
[On-Demand Webinar] HAProxy Data Plane API: True Dynamic Configuration Management
Integrating HAProxy into automation tools, continuous-delivery pipelines, and service meshes just got a lot easier. We’ve introduced a new REST API that you can use to configure HAProxy fully at runtime and it’s called the Data Plane API. Tune into this webinar to...
LUA
Enabling CORS in HAProxy
The HAProxy Cross-Origin Resource Sharing (CORS) Lua module streamlines adding CORS to your APIs. What is CORS? Read on to learn more.It doesn't matter whether you're using Angular, React, Vue or simple, vanilla JavaScript. You're guaranteed to need to fetch or...
5 Ways to Extend HAProxy with Lua
Use Lua to add fetches, converters, actions, services and tasks to HAProxy. Did you know that HAProxy embeds the Lua scripting language, which you can use to add new functionality? HAProxy features an extremely powerful and flexible configuration language and gives...
Let’s Encrypt (ACMEv2) for HAProxy
HAProxy Technologies is proud to announce the availability of an integrated Let’s Encrypt ACMEv2 Lua client for HAProxy and HAProxy Enterprise (HAPEE). HAProxy Enterprise comes bundled with Lua support in a precompiled binary conveniently distributed using your Linux...
HAProxy 1.6-Dev1 and LUA
HAProxy 1.6-dev1 Yesterday, Willy has released HAProxy 1.6-dev1: ANNOUNCE HAProxy 1.6-dev1. This version contains many new features and core improvements. Amongst the new features, one is LUA, contributed by Thierry (HAProxy Technologies developer). NOTE: We invite...
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