http://documentation-devel.engineering.redhat.com/docs/en-US/JBoss_Enterprise_Web_Server/2/html/HTTP_Connectors_Load_Balancing_Guide/Apache_HTTP_Overview.html

Following text (all about session replication) is valid for EAP and not for EWS. Should be removed.

{remove}
HTTP 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 takes the load of the disabled node. Two distinct functions must be performed:

Session state replication
Load-balancing HTTP Requests

Sessions state replication is handled by JBoss at the application level.
Load balancing, however, requires an external load balancer. A cost effective way of managing load-balancing is to set up a software load balancer using Apache httpd and mod_jk.
{remove}