How to design a call back service ?

Question

Hi,
Could you help me understand whether this is possible or whether I am on the right track with what I am trying to achieve?
Client
(C# Winform) ---- Send a Message to Service Bus [SB]
Please Keep in mind that Client can be ASP.NET MVC/Mobile App.
Message Handler
[SB] <----> Handler Reading the Message and Perform Long Running Task Like OCR/Download File, Then Return the Data/File Back to the Client.
Question:
Handler
- Currently thinking of Writing Console App - light
How do I keep Client and Handler (Talk to each other - mind blogging) ?
How/What method to use? to Notify the Client that the OCR task is complete (Async Call/Callback) so that it is not blocking the UI Thread.
- My thinking is having a 2nd Service Bus Queue.
Then when the Handler completed it task, send a message to the 2nd queue where the Client is Waiting/Listen for the Message.
Is this where SignalR come to play (Some How), I have read SignalR Vaguely about real time handling?
I am thinking of Cloud based solution
Am I on the right Track, Do you have any Recommendation or approach please Shed some light ?
Many Thanks.
Regards Dat.
Cool

Answer 1

Serkant, yes I did stumble across your suggested post:
https://code.msdn.microsoft.com/windowsazure/Brokered-Messaging-5be86bd9
I have follow through the step and stuck at the following code:
clear-host
Import-Module servicebus
new-psdrive -name ServiceBus -root c:\ps -psprovider ServiceBusPowerShellProvider
set-location ServiceBus:\
$Namespace = 'testqueue'
$key = "iH/NjKuGy......"
Set-ServiceBusCredentials -Namespace $Namespace -IssuerSecret $key
cd queues
dir
I get an error message: No Cache info available getting resources for path c:\ps
When I am copy the Key from Azure Service Bus > Name Space > Queue Name > View Connection String > SAS Key (Endpoint=sb://mytestqueue.servicebus.windows.net/;SharedAccessKeyName=wdfull;SharedAccessKey=iH/NjKuGy.....
I tried both:
Where $Key =iH/NjKuGy.....
(From SharedAccessKey=)
and $Key = Endpoint=sb://mytestqueue ....
What should the Key be the Whole String (Endpoint ... ?
 -IssuerSecret $key
I can't get the message in the queue and no error message (I've check on the Azure Service Bus Portal, the message is still exist in the Queue).
I have assigned the SAS Key with Full Access
clear-host
Import-Module servicebus
new-psdrive -name ServiceBus -root c:\ps -psprovider ServiceBusPowerShellProvider
set-location ServiceBus:\
$Namespace = 'testqueue'
$key = "iH/NjKuGy......"
Set-ServiceBusCredentials -Namespace $Namespace -IssuerSecret $key
$message = Receive-Message -From testqueue
$message
The above I get an error:
Receive-Message : There were not enough free threads in the ThreadPool to complete the operation.
At line:8 char:1
Receive-Message -From testqueue
CategoryInfo          : NotSpecified: (:) [Receive-Message], UnauthorizedAccessExceptionFullyQualifiedErrorId : System.UnauthorizedAccessException,Microsoft.ServiceBus.Samples.ReceiveMessageCmdlet
Do you know why I need new-psdrive in this service bus sample ? when I run the script the second time,  I get an error message: psdrive already exists.
At the moment I am stuck, I can't receive message not sure what is the cause I also try with the Master Key from the Name Space (Still doesn't help).
Thanks again.
Regards Dat.