Server cluster
From MoodleDocs
A Server Cluster is a group of servers that appear to the client as one server. The key to the linix server cluster ip_vs code.
To begin with, here are some interesting discussion about running moodle in a cluster configuration:
TCP Load Balancing Discussion http://moodle.org/mod/forum/discuss.php?d=49986
Moodle Clustering http://moodle.org/mod/forum/discuss.php?d=57202
Installation for 3000 simultaneous users http://moodle.org/mod/forum/discuss.php?d=88214
