Scheduler does not run until WEB API server receives its first HTTP Request

[amande4x]

I have scheduled my scheduler to run every 1 minute. But after I deploy by server and recycle my app-pool, scheduler does not run. It only starts running when it receives first HHTP request from UI front end.
How can i overcome this dependency?

[jamesmh]

Are you using IIS? Which version? Which version of .NET?

[amande4x]

IIS - Version 10, .NET 8.
I would appreciate it, if you can you please prioritize this issue? It's causing significant problems for my client.

[srivastava-prashant]

We too are facing issue, I see - until you launch the application and it makes first API call Coravel's Scheduler does not even initiate. The problem we face here is - If you have frequent release for product. And, you mostly prefer to deploy during Off business hours.

Then, in that case unless we explicit browse the application that would not trigger. And, If no one launch the application for a while post release then it would potentially impact the system. Because, there could be data which your system was expecting but it won't come through as the Coravel's Scheduler has even initated.

[jamesmh]

Check out these closed issues that should help:

• Scheduled task DailyAtHour sometimes skip weekend #211
• Scheduler is not working #27

Check out these articles linked by the issues:

• https://www.nickedeye.com/iis-keep-website-alive-always-running/
• https://weblog.west-wind.com/posts/2013/oct/02/use-iis-application-initialization-for-keeping-aspnet-apps-alive

[srivastava-prashant]

Check out these closed issues that should help:

• Scheduled task DailyAtHour sometimes skip weekend #211
• Scheduler is not working #27

Check out these articles linked by the issues:

• https://www.nickedeye.com/iis-keep-website-alive-always-running/
• https://weblog.west-wind.com/posts/2013/oct/02/use-iis-application-initialization-for-keeping-aspnet-apps-alive

Per this link (https://www.taithienbo.com/how-to-auto-start-and-keep-an-asp-net-core-web-application-and-keep-it-running-on-iis/) it seems that we would need to set the .NET CLR to .net 4.
But, our API is in .NET 8. And for .NET core based project Microsoft guidelines are to use "No Managed Code" in .NET CLR ( https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/advanced?view=aspnetcore-8.0 )

Can we safely ignore this NET CLR option and continue to be "No Managed Code" ?

[jamesmh]

Not sure, it's been a few years since I've touched IIS. My best advice is to try the non CLR approach and see if you get the relevant options in IIS? Try testing in a dev environment to see if things work out.

[ratanservegar]

Just to add to this, I spent over 3 days trying to get this to work, I have given up. I have ensured that my App pool is always running (can see the process up and running in task manager). have also preloaded my api (i see a request being logged when i start and stop the app pool) and I have also made sure that the application is using <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>... no matter what Coravel scheduler fails to start a scheduled task.. I am not sure what else I need to do in order to get the scheduler to work...... @jamesmh any ideas?