Tag Archives: layer7

HAProxy, Varnish and the single hostname website

As explained in a previous article, HAProxy and Varnish are two great OpenSource software which aim to improve performance, resilience and scalability of web applications. We saw also that these two softwares are not competitors. Instead of that, they can … Continue reading

Posted in Aloha, architecture, HAProxy, performance | Tagged , , , , , , , , , , | 32 Comments

HAProxy and Varnish comparison

In opensource world, there are some very smart products which are very often used to build a high performance, reliable and scalable architecture. HAProxy and Varnish are both in this category. Since we can’t really compare a reverse-proxy cache and … Continue reading

Posted in HAProxy, performance | Tagged , , , , , , , | 7 Comments

HTTP request flood mitigation

In a recent article, we saw how we can use a load-balancer as a first row of defense against DDOS. The purpose of the present article to provide a configuration to protect your applications against HTTP request flood. The configuration … Continue reading

Posted in Aloha, HAProxy, layer7, security | Tagged , , , | 6 Comments

Preserve source IP address despite reverse proxies

What is a Reverse-Proxy? A Reverse-proxy is a server which get connected on upstream servers on behalf of users. Basically, it usually maintain two TCP connections: one with the client and one with the upstream server. The upstream server can … Continue reading

Posted in Aloha, architecture | Tagged , , , , , | 3 Comments

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) Citrix … Continue reading

Posted in benchmark, performance | Tagged , , , | 15 Comments

load balancing, affinity, persistence, sticky sessions: what you need to know

Synopsis To ensure high availability and performance of Web applications, it is now common to use a load-balancer. While some people uses layer 4 load-balancers, it can be sometime recommended to use layer 7 load-balancers to be more efficient with … Continue reading

Posted in HAProxy, layer7, optimization | Tagged , , , | 4 Comments

Protect Apache against “apache killer” script

What is Apache killer? Apache killer is a script which aims to exploit an Apache Vulnerability. Basically, it makes Apache to fill up the /tmp directory which makes the webserver unstable. Who is concerned? Anybody running a website on Apache. … Continue reading

Posted in security | Tagged , , , , | 4 Comments