It seems that my asp.net sites on my web server are very slow to load if they have not been accessed in a while.
Does the ASP.NET processor go into suspend or sleep mode if it has gone unused for a period of time?
Is it better for me to fix this by configuring ASP.NET or writing some program to visit my sites every so often to keep it awake?
Depending on your configuration the Application Pool assigned to your ASP.net application the AppPool will recycle at a certain time of day, or after a certain number of requests. Once this happens it forces ASP.net to recompile the site. There is a good overview on ASP.net compilation on MSDN.
There are also several questions on StackOverfolow:
There are two steps that I use to make this better:
As an example, if you were able to identify that your site is rarely used at 0200 you could configure your Application Pool as follows (IIS Config -> Right Click the AppPool -> Click "Recycling..."):
(source: richard-slater.co.uk)
The above dialog is from Windows 7, however I don't think the dialog has changed vastly between Windows 2008 and Windows 7/2007 R2.
It could be that the application pool has been idle. You can change the idle time out the setting to 0 (zero) which effectively disables the timeout so that the application pool will never shut down due to being idle. You can find this setting in gui under advanced settings. See this blog post: http://brad.kingsleyblog.com/IIS7-Application-Pool-Idle-Time-out-Settings. You can also use a tool like smartping ( I have not used id) http://forums.smartertools.com/showthread.php/8511-SmarterPing-Website-Keep-Alive-Utility. Also there a new module from Microsoft that works with IIS7.5 http://www.iis.net/downloads/microsoft/application-initialization info here http://www.iis.net/learn/get-started/whats-new-in-iis-8/iis-80-application-initialization#TOC301259898