19.5. Web, HTTP Connectors, and HTTP Clustering

19.5.1. About the mod_cluster HTTP Connector

The mod_cluster module enables load balancing in the JBoss Web container and is referred to as a connector. To learn about other connectors, see one of the following:
The mod_cluster connector has several advantages over other connectors.
  • The mod_cluster Management Protocol (MCMP) is an additional connection between the JBoss Enterprise Application Platform 6 servers and the Apache HTTP Server with the mod_cluster module enabled. It is used by the JBoss Enterprise Application Platform servers to transmit server-side load balance factors and lifecycle events back to the Apache HTTP Server via a custom set of HTTP methods.
  • Dynamic configuration of Apache HTTP Server with mod_cluster allows JBoss EAP 6 servers to join the load balancing arrangement without manual configuration.
  • JBoss EAP 6 performs the load-balancing factor calculations, rather than relying on the Apache HTTP Server with mod_cluster. This makes load balancing metrics more accurate than other connectors.
  • The mod_cluster connector gives fine-grained application lifecycle control. Each JBoss EAP 6 server forwards web application context lifecycle events to the Apache HTTP Server, informing it to start or stop routing requests for a given context. This prevents end users from seeing HTTP errors due to unavailable resources.
  • AJP, HTTP or HTTPS transports can be used.