> Is it possible to replicate a Moodle server, or is that what clustering is?
In a http://en.wikipedia.org/wiki/Computer_cluster
the components "are usually connected to each other through fast local area networks". Since your two servers are going to be in two different places (LANs) clustering is not what you are talking about.
The term which is used most often in this forum is mirroring, as in http://en.wikipedia.org/wiki/Mirror_%28computing%29
. Mirrors used to be copies of FTP
servers to avoid bottlenecks in their network connection, the SWITCH mirror http://mirror.switch.ch/
Now the bad news: The technology behind Moodle makes it unsuitable for mirroring. The short explanation is that Moodle needs three data storage areas, the database, moodledata and session files, which have to be synchronized very fast, almost instantaneous.
This has been discussed often in this forum. Use the 'advanced search facility' linked to the introduction to this forum. Here's an example: "How to Replicate MOODLE ??!!" http://moodle.org/mod/forum/discuss.php?d=173408
. (Yes, some use the term replication, but that term is commonly used to mean database replication. See http://en.wikipedia.org/wiki/Replication_%28computing%29
> We have a Moodle server running at our area data centre, however, our WAN traffic makes response times to our server less than ideal. I had thought that if it were possible to run a replica of our server locally, then using DNS redirects, the students would access our local machine while at school, and then it may sync data over the WAN to keep all things the same, so that when the students go home, they would then see the Data Centre machine.
The root cause is the slow Internet connection of the school, right? How come? Fast connections are not expensive these days. See also, "Need help regarding high availability" http://moodle.org/mod/forum/discuss.php?d=149182#p652633
. (Sorry, it is not about http://en.wikipedia.org/wiki/High_availability