如何在ASP.NET中动态运行进程

Question

I am designing a website and it uses Windows Forms (in Visual Studio 10) in which for example i have five-six URLs . Now i am displaying them on home page of my website xyz.com

What i want is, i want to calculate total no. of tweets for all links and display links based on no. of times they are being tweeted/retweeted.

for a url we can calculate no. of tweet using twitter api http://urls.api.twitter.com/1/urls/count.json?url=YourURL

I know all the stuff like receiving JSON values in a string and parsing json to retrieve tweet counts and then compare and display links based on the priority etc.

What i have been using till now it is initiating all the process using a Click_Button.

But i want to know how can i automate this all for each 10 minutes. Its like a end user can see urls priority with just refreshing the page.

Answer 1

One way to do this is to run a scheduled task ever 10 mins which interacts with the DB. The web application also interacts with the DB and thus the two systems are distinct.

Side note: it is strongly recommended to use only console applications as scheduled tasks. If you make a windows form application will will have some issues.

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As Kieren Johnstone has pointed out in another answer the best way to do this would be to write a windows service.

I still recommend the solution as described above as a first step since it is easy to debug and test.

Additionally, give some serious consideration to logging and error reporting -- with background tasks you can never know to much about what the heck it was doing when it broke.

Answer 2

If timing itself is not important (it doesn't have to be 10 minutes precisely), I would suggest binding to any event that fires when users use your application. No point in calculating anything if noone is using it :-)

So you could use a login, or page load, or whatever happens at an interval roughly like the interval you wish to achieve.

You can always store a DateTime variable somewhere that you can check to see when the calculation was last made. Something like:

public void MyEventHasFired()
{
     DateTime dateLastProcessed = ... //Database? Session data? Anything goes.
     if(dateLastProcessed < DateTime.Now.AddMinutes(-10))
     {
          //calculate

          ...

          dateLastProcessed = DateTime.Now;
     }
}

Answer 3

The best solution is definitely a Windows Service. It can be started, stopped and managed well, it's easy to log, maintain..

Scheduled Tasks are very prone to problems. At least in a Windows Service you can configure it to start automatically, re-start if there's a problem, you can control the timing yourself in the code, and catch/handle exceptions as you wish.

Answer 4

The best scheduler i know is Quartz.net

It'is not simple to use but it works great.

You can find an example with asp.net there http://blogs.planetcloud.co.uk/mygreatdiscovery/post/ASPNET-Scheduled-Tasks-with-QuartzNET.aspx

Anyway i agree with Kieren Johnstone: you should use a windows service