HAProxy — The best open source load balancer, without a doubt

It's really annoying when people believe that something traditional (proven to work) is somehow worse, than something that is modern (looks like a cool idea).

It’s no big secret that a single processor can only handle so much processing in a given time. So what happens when you reach the limits of what a single processor can handle? Simple, you add more processors.

Cloudflare provides a content delivery network (CDN). A CDN is a worldwide network of servers that delivers web content to clients based on the geographic location of the client.

Load balancing NFS is a real pain — especially when it comes to the locked mounts issue. In this blog I'll explain how to create a highly available NFS server for Kerberos.

As I design, build and sell load balancers based on LVS and HAProxy, it’s in my interests to combat the avalanche of NGINX+ marketing propaganda that I've seen over the last year. Let's call it an attempt to skewer fake news.

HAProxy is awesome. So awesome in fact, that here at Loadbalancer.org HQ - I find it very difficult to generate enough load to break it...so let's try harder!

Open standards are awesome, and the File Transfer Protocol FTP (inspite of its flaws) has been in constant use for an amazing 40 years! FTP can be a pain to run over firewalls and load balancers, so this blog explains how to configure Microsoft FTP and HAProxy.

Using client certificates for security is a pretty cool idea! You can protect an entire application or even just a specific Uniform Resource Identifier (URI) to only those that provide a valid client certificate.

HAProxy Technologies' ALOHA Pocket is a full-featured ALOHA Load Balancer running on a light USB-powered hardware that easily fits in a pocket, meaning it's possible to carry it everywhere to run tests and demos.

HAProxy is an excellent choice if you need layer 7 functionality, but its a full reverse-proxy, so the application thinks that all of the traffic is coming from HAProxys IP - rather than the clients.

Once HAProxy is running transparently, it will allow the real server to see the client IP so the real server will reply directly back to the client bypassing the load balancer.

Anomaly score based blocking is more flexible and effective than simple first error blocking.

One of our favorite methods of load balancing is using Layer 4 DR because it is transparent and fast. Unfortunately, because of Amazon's infrastructure, this is not possible in EC2 so we need to use another method which means we are left with layer 4 NAT and transparent HAproxy using TProxy.

Denial of Service (DOS) attacks can be used to degrade or cripple the functionality of a site.

The media industry had lots of fun at the expense of e-commerce outlets on Black Friday, mercilessly reporting on site crashes and outages.

By default, the source IP address of the packet reaching the web servers is the IP address of the load balancer and not the IP address of the client.

There are a lot of SSL offload throughput statistics available for appliances across the internet but rarely do they detail the way they were tested.

The ideal way to monitor the health of the real servers is to to have a dedicated monitoring system in place such as Nagios. However this isn’t always an option, so for some they require the loadbalancer to send an alert.

In general when you are load balancing a cluster you can evenly spread the connections through the cluster. However, with some applications, you might get very high load from just a few users doing heavy work, which can compromise performance.

Some of the most common questions we get at Loadbalancer.org are performance related. It is quite difficult to give a straight answer to these questions as the real answer is often slightly unsatisfactory.

As of haproxy-1.6-dev1 it is now possible to send email alerts directly from HAProxy thanks to the excellent work done for us by Simon Horman.

Transparent mode with HAProxy allows you to see the IP Address of the clients computer while still having a high availability service using HAProxy.

This Blog is for anyone wanting to load balance the Exchange 2010 CAS role using only open source software.

I get quite frustrated with benchmarks because they are very hard to perform properly, and even when you do them properly its very hard to get any useful data from them.

Here at Loadbalancer.org we have recently started the certification process of our product with Microsoft Office Communications Server (OCS).