Common Ways of handling long running process in ASP.NET

Question

We have a long running data transfer process that is just an asp.net page that is called and run. It can take up to a couple hours to complete. It seems to work all right but I was just wondering what are some of the more popular ways to handle a long process like this. Do you create an application and run it through windows scheduler, or a web service or custom handler?

Answer 1

Windows Workflow Foundation

What I find the most appealing about WF, is that workflows can be designed without much complexity to be persisted in SQL Server, so that if the server reboots in the middle of a process, the workflow can resume.

Answer 2

A windows service is the typical solution. You do not want to use a web service or a custom handler as both of those will lie prey to the app pool recycling, which will kill your process.

Answer 3

I use two types of processes depending on the needs of my BAs. For transfer processes that are run on demand and can be scheduled regularly, I typically write a WinForms (this is a personal preference) application that accepts command line parameters so I can schedule the job with params or run it on demand through an interactive window. I've written enough of them over the last few years that I have my own basic generic shell that I use to create new applications of this nature. For processes that must detect events (files appearing in folders, receiving CyberMation calls, or detecting SNMP traps), I prefer to use Windows Services so that they are always available. It's a little trickier simply because you have to be much more cautious of memory usage, leaks, recycling, security, etc. For me, the windows application tends to run faster on long duration jobs than they do when through an IIS process. I don't know if this is because it's attached to an IIS thread or if its memory/security is more limited. I've never investigated it.

I do know that .Net applications provide a lot of flexibility and management over resources, and with some standards and practice, they can be banged out fairly quickly and produce very positive results.

Answer 4

In a project for long running tasks in web-application, i made a windows service. whenever the user has to do the time-consuming task, the IIS would give the task to the service which will return a token(a temporary name for the task) and in the background the service would do the task. At anytime, the user would see the status of his/her task which would be either pending in queue, processing, or completed. The service would do a fixed number of jobs in parallel, and would keep a queue for the next-incoming tasks.