Preventing Site Loading Delays due to ASP.NET Startup (Including DotNetNuke)
Reducing the delay time upon first requests to a DotNetNuke or other ASP.NET website is something that I see asked quite often. This delay is due to the ASP.NET Worker Process compling a website, this articles will discuss the solutions available to prevent this delay from occuring. I personally find that the simplest solution is the best; the even better part is that it is free! First of all before I talk about the different solutions available let me first explain the issue and why it happens.
Depending on your specific setup and hosting environment this initial load time can be quite lengthy. I have noticed initial load times of anywhere from 4-5 seconds to over 25 depending on the server configuration and load. What is actually happening is that your DNN site is being compiled after the ASP.NET worker process has restarted. The worker process can restart for many reasons, however the most troubling one is due to site traffic. By default IIS will shut down the ASP.NET worker process after 20 minutes of inactivity meaning that the next request will restart the worker process and cause the compilation to occur.
Solutions
Now there are many different solutions to this issue I have recently noticed 4 distinct common recommendations. The first recommendation is a very simple fix, however, for those of us in shared hosting environments we cannot perform the needed changes. If you have access to administer IIS you can change the recycling properties of the ASP.NET worker process for your specific application pool. I have heard of many users changing the value from 20 minutes to be 6-8 hours to ensure that the process does not end until extreme cases of inactivity.
The second method to resolve this issue is the one that I personally use for all of my websites DotnetNuke or ASP.NET. This method relies on using an external service to “request” a page of your site every __ minute. DotNetNuke even provides a .aspx page that you can use for this purpose to limit the bandwidth used by these “keep alive” processes; keepalive.aspx. http://www.host-tracker.com provides a free service to monitor your website the added benefit is that they will track your overall site uptime as well. I use them for this website and they are directed to http://www.mitchelsellers.com/keepalive.aspx for monitoring. This should do a good job to keep your site active as long as the monitoring location sends requests every 10-15 minutes.
The other two options are site isolated elements that I have not yet tested and these involve placing various pieces of code into your application to have it call itself just before the worker process is shutdown. This can be done via an HTTP Module or via the ASP.NET Website Heartbeat event monitoring. I personally have not used these methods as I do not want to modify the DNN core, or the core of any of my ASP.NET applications. However, if you search for these topics online you will find many examples.
Conclusion
I hope this has provided some helpful information regarding the delays experienced when requesting the first page for an ASP.NET website.
Posted by Mitchel on Wednesday, June 13, 2007
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