Question

I have recently started working for a new company and am now working on a web application (asp.net). This application uses the Global.asax to start a timer which will do various things at a given interval (send out emails, set various values in the database etc)

What they want now is to have something which will call a third party web service retrieve some data and update a database at our end. I would normally do all of the above in a windows service. However they seem happy to have this type of thing in the global.asax

I’m going to create a new project and develop this new functionality as a windows service, but should I bother? Maybe I should just add this to the global.asax?

My question is what is the most appropriate/best approach for the above scenarios?

Answer 1

The use of an external service is the best choice.

1. An unhandled exception in a thread not associated with a request will take down the process. This occurs even if you have a handler setup via the Application_Error method.

2. If you run your site in a Web Farm, you could end up with multiple instances of your app that all attempt to run the same task at the same time. A little more challenging to deal with than the first item, but still not too hard. One typical approach is to use a resource common to all the servers, such as the database, as a synchronization mechanism to coordinate tasks.

3. The AppDomain your site runs in can go down for a number of reasons and take down your background task with it. This could corrupt data if it happens in the middle of your code execution.

For more info:

• Execute method in global.asax every few minutes

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