Execute method in global.asax every few minutes

Question

What is the most effective way to execute a method in the Global.asax file every x number of minutes? Is there a way to have the ASP.NET server run a background thread that fires a tick event after a certain elapsed period?

Solution

You could have a timer in the Application_Start of the Global.asax, but this is not very flexible since you need to do a request to the application for the timer to start. There are dangers to doing it this way though, as detailed by Haacked:

• http://haacked.com/archive/2011/10/16/the-dangers-of-implementing-recurring-background-tasks-in-asp-net.aspx

A better way of doing it is to have a web service that acts as an interface to your ASP.NET application and have a windows service that calls your web service on scheduled intervals:

More details here:

• http://msdn.microsoft.com/en-us/magazine/cc163821.aspx

Comments

[Chris Gessler]

You beat me by 22 seconds, but I actually typed something :)

[Chris Sinclair]

If you do not have access to your server (say it's hosted by a third party) and cannot install Windows services, then you can fake one using the ASP.NET cache: codeproject.com/Articles/12117/…

[carlbenson]

In my particular case, I am okay with requiring a request to be made for the application to start. Your web service idea is great though, and definitely a more appropriate answer for generic cases of my question. Thanks a lot!

[Moiz Tankiwala]

Not a very good idea. An ASP.Net application may have been shut down (typically the configuration of hosted web servers, where application is shut down after a period of inactivity and only started on receiving a new request).

[Fandango68]

@ChrisSinclair is 100% spot on. You should not be developing, with the mindset that you have full access to company resources or client resources. Everything should be portable and expandable, and hence a ASP.net cached solution is really the only way to go.

[Fandango68]

@MoizTankiwala is correct. Not a good idea. Most web services have a timeout, which you may not have control over. Web servers may crash. Then what!? You may need to host your ASP.net page on a remote service that at least gives some gaurantees it won't stop - cloud, etc. Try to avoid using server internals to do the job. Use the cache!