Question

Scenario
I have an web application which needs some calculations and processing on data. This job is a long running job(few hours). Job is initiated by user.

Requirement.

1. User Clicks on Process Data.

2. Some functions are called to start data processing.

3. Data Processing runs for hours.

4. User is given feedback of percentage completed etc.

5. Even if user logs off and then again log on he should get this feedback.

The requirement is somewhat similar to Spiceworks. Where it runs in background to detect the devices/computers in network and the user is notified in his page about the progress. But spicework uses windows service. We don’t want to us windows service.

Now the question is.

1. What if user closes the page, will the task still run in background.

2. This task has to be completed fully.If terminated in between output will not have any meaning.

3. How to actually to design this long running process. In ASP.Net environment.

4. Also is there a way to show all/same user who logs in the status of processing.

Answer 1

There are multiple ways to schedule a job in the background. You can use SQL Job, Windows Service or Scheduled Tasks.

I would design it like this:

From my ASP.NET page – I will store an indication in the database for the job to start which will then be picked by the scheduled task. This task is nothing but a console application which pulls data from the database to see which tasks user initiated and then take the next action in there.. For the percetage complete you can store those values from your job into DB and your page will access the dB to show it to user anytime they come to the page.

Here is another thread where long running tasks in IIS are discussed:
Can I use threads to carry out long-running jobs on IIS?