This article contains step by step instructions for configuring an Apache 2.x web server which handles static content and delegates JSP (Java Server Pages) and Servlet requests to two Tomcat 4.x servers using AJP 13 connectors and a load balancing worker.
Introduction
Apache 2.0 is a standards compliant, fast and mature web server which excels at delivering static content such as static HTML pages and images. The Tomcat web server is great for serving Java Server Pages and servlets, but it is not as fast as Apache for delivering static content.
In order to build a fast, scalable web application, the requirements call for an Apache server that delegates servicing of JSP and servlet requests to multiple tomcat servers by using an Apache module, mod_jk, that performs load balancing with session affinity, also known as “sticky” sessions.
Session affinity explained. When a client browser requests a JSP page for the first time, the load balancer redirects the request received by Apache to one of the two tomcat servers; further requests originating from the same client session will be automatically forwarded to the same tomcat server, so that the user’s session data is retrieved.
This document describes how I configured Apache 2.x to dispatch JSP and servlet requests to two Tomcat 4.x instances listening on different ports. This setup was done on a Linux system. Your mileage may vary.
