Set up mod_cluster to grow and shrink your application at will
Mod_cluster is the next generation connector from JBoss. Like other software load balancer, it serves to be the bridge between web server and application server. Unlike mod_jk and mod_proxy, mod_cluster allows an application server to grow / shrink dynamically without needs for reconfiguration. Additionally, mod_cluster leverages a second communication channel which allows it to have more robust load balancing options as well as being more than just application server aware – it is also application aware meaning that it can detect scenarios where an application server is up but an application is not available and thereby not route traffic to it. In our example system, we introduce mod_cluster as a way of creating a more robust and dynamically discovered middle tier to our environment. With mod_cluster in place, if our monitoring team sees an increase in traffic to our application, planned or unplanned, we can have our team that is responsible for environments create another instance of our application on a new virtual or physical server and, once started, that instance is now immediately able to start taking on load. Using mod_cluster doesn’t stop a failure point so much as it allows business to continue on without