Load balancing with the Apache http server
Balancing Act

© sTan, Fotolia
Today's web performance and availability requirements make load balancing indispensable. In this article, we show you how to set up an effective load balancing system using features built into the Apache web server.
A multitude of technologies support load balancing for web servers. Load balancers come in all shapes and sizes, from simple DNS-based techniques through vast and versatile proprietary systems. In some cases, however, the load balancing features you need might be available already through the Apache web server. In this article, I describe some strategies for load balancing with Apache.
Preparation
The schematic in Figure 1 shows the underlying structure of a software-based balancing system. In this scenario, several front-end load balancers accept incoming user requests and distribute them to a pool of back-end servers on the basis of a predefined scheme. Multiple individual systems can run in parallel to provide a fail-safe (shown in the background in Figure 1). Apache includes a number of modules for supporting load balancing (Table 1), and you'll need to make sure any modules you intend to use are loaded:
LoadModule xyz_module modules/mod_xyz.so
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

News
-
Akamai Will Host kernel.org
The organization dedicated to cloud-based solutions has agreed to host kernel.org to deliver long-term stability for the development team.
-
Linux Kernel 6.14 Released
The latest Linux kernel has arrived with extra Rust support and more.
-
EndeavorOS Mercury Neo Available
A new release from the EndeavorOS team ships with Plasma 6.3 and other goodies.
-
Fedora 42 Beta Has Arrived
The Fedora Project has announced the availability of the first beta release for version 42 of the open-source distribution.
-
Dash to Panel Maintainer Quits
Charles Gagnon has stepped away as maintainer of the popular Dash to Panel Gnome extension.
-
CIQ Releases Security-Hardened Version of Rocky Linux
If you're looking for an enterprise-grade Linux distribution that is hardened for business use, there's a new version of Rocky Linux that's sure to make you and your company happy.
-
Gnome’s Dash to Panel Extension Gets a Massive Update
If you're a fan of the Gnome Dash to Panel extension, you'll be thrilled to hear that a new version has been released with a dock mode.
-
Blender App Makes it to the Big Screen
The animated film "Flow" won the Oscar for Best Animated Feature at the 97th Academy Awards held on March 2, 2025 and Blender was a part of it.
-
Linux Mint Retools the Cinnamon App Launcher
The developers of Linux Mint are working on an improved Cinnamon App Launcher with a better, more accessible UI.
-
New Linux Tool for Security Issues
Seal Security is launching a new solution to automate fixing Linux vulnerabilities.