We have made good experiences with the following setup:
- One server running a reverse proxy (we are using pound)
- One server with an aolserver instance (no openacs) serving "static images" (served from the file system not the content rep)
- One server with the openacs installation
- One db server (pg)
- The proxy uses the url to divide the requests between the image server and the openacs server
All servers are running linux rh8. We are currently using only one openacs server but of course that could be several machines as well. The proxy could do the load balancing. Unfortunately the more servers you have the more work you will have with handling failover problems :)
As far as openacs itself is concerned i think we (Vienna Univ of Business Admin) will have the same performance problems in a few weeks. I think a good point to start enhancing dotlrn performance is the portal system. For all community-portals (dotlrn_class, dotlrn_class_instance, dotlrn_club, dotlrn_department) but the user portal i have ripped out the real portal-system and created a "static" version where all portlet are called directly with given parameters (=unchangeable portal layout). Next important thing will be to enhance the real portal system and to cache portlet content.
