Installation guide

Chapter 1. Overview
Apache HTT P server ("Apache") is a well-known web server which can be extended using plug-ins. T he
Apache Tomcat Connector mod_jk is a plug-in designed to allow request forwarding from Apache to a
servlet container. T he module also supports load-balancing HT T P calls to a set of servlet containers
while maintaining sticky sessions.
HTT P session replication is used to replicate the state associated with web client sessions to other
nodes in a cluster. If one node becomes unavailable, another node in the cluster continues to service the
failed node's requests. T his involves two distinct operations:
Session state replication
Load-balancing HT T P Requests
Session state replication is handled by JBoss per application, providing the application is configured to
make use of this feature (refer to Section 17.1, “Enabling session replication in your application”).
Load balancing must be handled externally to JBoss, via either hardware or software. A cost-effective
way of enabling load balancing is to set up a software load balancer using Apache and the Apache
Tomcat Connector (mod_jk).
JBoss Enterprise Application Platform 5 HTTP Connectors Load Balancing Guide 11