I currently look after a Virtual Learning Environment (VLE) which is based on DNN. It was built in the DNN 4.0 days has has around 30 custom modules for the VLE functions. We have upgraded DNN along the way and currently at the latest 5.51. I have a few concerns around the performance and CPU usage and footprint of the worker process servicing the website.

Currently we have 4 servers, 2 x Win 2003 IIS servers running .Net 4.0 and 2 x Win 2008 SQL boxes. There is a load balancer sitting infront of the 2 IIS servers.
The IIS servers are 8-way 2.13Ghz XEON with 6Gb RAM.

What we are noticing is the sites crawling during peak periods when student login to do their study. The worker process can be anywhere from 200,000K to 700,000K during this time with CPU utilisation around the 30-50% mark.
Am I right in assuming this is a little too high?
It should be noted that our DNN instance hosts around 20 Portals. 5 of which are quite active with students logging in for study.

My client has asked me to look around at performance guidelines as I would have thought our hardware would be more than enough to handle the load. But quite clearly, something hardware, DNN, environment wise is not right.

Any help would be appreciated.

I have done quite a bit of reading around IIS performance tuning but with .net 4 the machine.config has an autoconfig element which apparently prepares the environment for optimal performance based on the server config.

Cheers
Anthony Roche

Hi Anthony, Did you get any response on this? We are currently load testing a new site and are having major issues with CPU usage. We have a very similar set up, but with three web servers, and we seem to start hitting issues at around the 1,000 concurrent users mark. How many users are you able to server before the server maxes out? Cheers, Ian