How to make azure webjob run continuously and call the public static function without automatic trigger

Question

I am developing a azure webjob which should run continuously. I have a public static function. I want this function to be automatically triggered without any queue. Right now i am using while(true) to run continuously. Is there any other way to do this?

Please find below my code

   static void Main()
    {
        var host = new JobHost();
        host.Call(typeof(Functions).GetMethod("ProcessMethod"));
        // The following code ensures that the WebJob will be running continuously
        host.RunAndBlock();
    }

[NoAutomaticTriggerAttribute]
public static void ProcessMethod(TextWriter log)
{
    while (true)
    {
        try
        {
            log.WriteLine("There are {0} pending requests", pendings.Count);
        }
        catch (Exception ex)
        {
            log.WriteLine("Error occurred in processing pending altapay requests. Error : {0}", ex.Message);
        }
        Thread.Sleep(TimeSpan.FromMinutes(3));
    }
}

Thanks

You dont need the whole JobHost thing you have there, you can simply call ProcessMethod from Main and use Console.WriteLine to log. — Amit Apple, Apr 14 '15 at 17:12
Hi, I have just shown a simple example in ProcessMethod to log. Other than logging, the ProcessMethod does other processes ie. calling database, update sql table , etc., — Mukil Deepthi, Apr 17 '15 at 08:43
@AmitApple What if you want to have a cancellation token to allow a graceful shutdown? Is it needed then? (Acknowledging support for this may have been added after your comment) — xr280xr, Jun 12 '23 at 16:45

score 27 · Accepted Answer · answered May 31 '15 at 00:01

27

These steps will get you to what you want:

Change your method to async
await the sleep
use host.CallAsync() instead of host.Call()

I converted your code to reflect the steps below.

static void Main()
{
    var host = new JobHost();
    host.CallAsync(typeof(Functions).GetMethod("ProcessMethod"));
    // The following code ensures that the WebJob will be running continuously
    host.RunAndBlock();
}

[NoAutomaticTriggerAttribute]
public static async Task ProcessMethod(TextWriter log)
{
    while (true)
    {
        try
        {
            log.WriteLine("There are {0} pending requests", pendings.Count);
        }
        catch (Exception ex)
        {
            log.WriteLine("Error occurred in processing pending altapay requests. Error : {0}", ex.Message);
        }
        await Task.Delay(TimeSpan.FromMinutes(3));
    }
}

answered May 31 '15 at 00:01

none

418
5
8

1

Is Thread.Sleep generally a problem in WebJobs e.g. in static (non async) functions? Thanks! – GGleGrand Dec 22 '15 at 16:00
If it's a scheduled or manual webjob you shoud get the task returned from CallAsync and call Wait() on it. – Giorgio Bozio Oct 02 '16 at 13:17
System.ArgumentNullException: 'Value cannot be null. Parameter name: method' – Neo Oct 08 '20 at 12:57
What is the purpose of `NoAutomaticTriggerAttribute`? What happens if you remove it? – xr280xr Mar 24 '23 at 04:16

Rocklands.Cave · Answer 2 · 2016-01-23T21:39:58.273

Use the Microsoft.Azure.WebJobs.Extensions.Timers, see https://github.com/Azure/azure-webjobs-sdk-extensions/blob/master/src/ExtensionsSample/Samples/TimerSamples.cs to create a trigger that uses a TimeSpan or Crontab instruction to fire the method.

Add Microsoft.Azure.WebJobs.Extensions.Timers from NuGet to your project.

public static void ProcessMethod(TextWriter log)

becomes

public static void ProcessMethod([TimerTrigger("00:05:00",RunOnStartup = true)] TimerInfo timerInfo, TextWriter log)

for five minute triggers (using TimeSpan string)

You will need ensure your Program.cs Main sets up the config to use timers as follows:

static void Main()
    {
        JobHostConfiguration config = new JobHostConfiguration();
        config.UseTimers();

        var host = new JobHost(config);

        // The following code ensures that the WebJob will be running continuously
        host.RunAndBlock();
    }

I do this, but it terminates after some days. My method is async Task ProcessTimer([TimerTrigger("00:01:00")]...). I run in Basic plan and Always On. — Eivind Gussiås Løkseth, Feb 14 '17 at 08:12
System.ArgumentNullException: 'Value cannot be null. Parameter name: method' — Neo, Oct 08 '20 at 12:58

How to make azure webjob run continuously and call the public static function without automatic trigger

2 Answers2