Send message to all clients if a recurringJob in hangfire is started using SignalR in .net core2

This is quite simple, if you have understood HangFire & SignalR concepts

You can simply place a function inside your Hangfire Job to call SignalR function inside it, to get state of Hangfire.IO and to send message to all users.

Suppose my recurring job name is : FullThings

Now when HangFire call this function(FullThings), place SignalR Hub Instance inside it and call required function, something like this

public string FullThing()
{
   hub = GlobalHost.ConnectionManager.GetHubContext<ClientPushHub>();
   hub.Clients.All.SendAlertAboutJob("Started");
   //Some code
     
}

You can also read these articles:

https://www.jerriepelser.com/blog/communicate-status-background-job-signalr/

http://docs.hangfire.io/en/latest/background-processing/tracking-progress.html

http://henriquat.re/server-integration/signalr/integrateWithSignalRHubs.html

Above links may make things more clear about SignalR and Hangfire for you.