doing scheduled background work in asp.net

Question

I need to perform periodically a certain task in my asp.net app so did like this:

protected void Application_Start()
{
    Worker.Start();
}

...
 public static class Worker
 {
   public static void Start()
   {
     ThreadPool.QueueUserWorkItem(o => Work());
   }
   public static void Work()
   {
      while (true)
      {
          Thread.Sleep(1200000);
          //do stuff
      }
    }
}

is this approach good ?

I saw a blog about the badge awarding on this site is done using an asp.net cache hack: https://blog.stackoverflow.com/2008/07/easy-background-tasks-in-aspnet/

score 2 · Accepted Answer · edited May 23 '17 at 09:59

You can use Timer class for task like this. I'm using this class in my own ASP.NET chat module for closing rooms after some expiration time and it works fine. And I think, it's better approach than using Thread.Sleep

Below example code:

using System;
using System.IO;
using System.Threading;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Worker.Start();
            Thread.Sleep(2000);
        }

        public static class Worker
        {
            private static Timer timer;

            public static void Start()
            {
                //Work(new object());
                int period = 1000;
                timer = new Timer(new TimerCallback(Work), null, period, period);
            }

            public static void Work(object stateInfo)
            {
                TextWriter tw = new StreamWriter(@"w:\date.txt");

                // write a line of text to the file
                tw.WriteLine(DateTime.Now);

                // close the stream
                tw.Close();
            }

        }
    }
}

with Timer I still have to do `ThreadPool.QueueUserWorkItem(o => Work());` ? the difference is that I don't need while(true) Thread.sleep anymore ? — Omu, Oct 04 '11 at 11:48
@Chuck, Yes, you don't need this stuff. Check my post now, I've written sample code that is doing exactly what your, but with Timer approach — Łukasz Wiatrak, Oct 04 '11 at 12:17
@Chuck, Work method never gets executed because program exits immediately. Timer object is disposed and timer thread is stopped after program exits. I've edited this program - added Thread.Sleep(2000) after "Worker.Start()". Now Work function has enough time to be executed. — Łukasz Wiatrak, Oct 04 '11 at 18:28

score 2 · Answer 2 · edited May 23 '17 at 12:18

Your method will work, but as Lucasus said, better approach will be using Timer class.

Other than that if you own the computer where your site is running I would recommend using Windows service for your scheduling tasks. This approach will proove itself more beneficial than timers of any kind inside of asp.net infrastructure. That is because everything that is working inside asp.net is going to be managed by asp.net engine and it is not something you want. For example worker process can be recycled and at this moment your task will break.

Detailed information about timers in windows services can be found here: Timers and windows services.

Information about windows services can be found here: Windows services

To hoock timer into windows service you need to create it at the start and handle events that it fires.

with Timer I still have to do `ThreadPool.QueueUserWorkItem(o => Work());` ? the difference is that I don't need while(true) Thread.sleep anymore ? — Omu, Oct 04 '11 at 11:48

score 1 · Answer 3 · answered Oct 04 '11 at 09:15

1

If you want do do a scheduled work, why not use Windows Task Scheduler ?

Some info I found, may be useful: http://www.codeproject.com/KB/cs/tsnewlib.aspx

Kris

answered Oct 04 '11 at 09:15

Drakkonite

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doing scheduled background work in asp.net

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