Azure Service Bus - Working With Queue In A Real World Scenario

This article explains a real-world business requirement and how Azure Service Bus Queue helps to fulfill the requirement.

Business Requirement

One of the utility bill payments company wants to build an application, which will do the mobile recharge for end users. The application should support all the operators which are available in the market. The flow is, the user sends SMS in predefined format and application should parse the message and do the recharge accordingly.

Now, the biggest challenge is the application gets a huge number of recharge requests during the peak hours and is not able to process each request, so the company is looking for something like where all the requests are parked when they come and process one by one.

Azure Service Bus

The company came to know about the Azure Service Bus provided by Azure, so he started exploring Azure Service Bus.

Azure Service Bus supports cloud-based message-oriented middleware technologies like Queue, Topic, and Relay.

Here in order to meet the business requirement, we will use the queue mechanism where all the requests will be added in the queue and another side queue listener will process the message by reading from the queue.

Queue

The sender sends the message, adds it into the queue and the receiver processes the message in a FIFO (First In First Out) manner. The benefit of using queue is, it creates decoupling between sender and receiver, means sender and receiver should not be available at the same time while sending the message as messages are stored in a queue. Another benefit is load leveling, which means sender sends messages at a different rate and the receiver can process messages at a different rate, as both are independent in sending and processing.

Now let's see the step by step implementation of the below to design a solution:

1. Create Service Bus Namespace
2. Create Queue
3. Add a message in the queue
4. Read Message from the queue
5. Scheduled Message
6. Receive Mode
7. Abandoned Async
8. Dead-letter Queue

Service bus namespace is a container for all messaging components. One namespace contains multiple queues and topics.

• Log in to the Azure portal via portal.azure.com
• Click on 'Create a resource' from the left navigation pane, click on 'Integration' and then 'Service Bus'.
  
  
  

• Enter the proper name for a namespace
• Select pricing tier, for demo purpose we have selected Basic
• Subscription and Resource group, keep it as it is
• Select your desired location and click on 'Create' button
  
  
  

Once you create a namespace, you can explore the same from the dashboard where you can find all the details which you have provided while creating a namespace.

Credentials

Click on 'Shared access policies' from the left panel, click on 'RootManageSharedAccessKey' to explore keys and connection strings which will be used further to connect.

• Click on 'Mobile Recharge' namespace on Dashboard
• Click on 'Queues' on the left pane and click on '+Queue' to create new Queue.
  
  
  

• Enter queue name and click on 'Create' button keeping the rest of the input as it is.
  
  
  

• Click on 'Queues' and you will get a list of created queues. You can also find our recently created queue; i.e. recharge.
  
  
  

• Create a console application in Visual Studio
• Set variables, one for connection string which you can copy from Shared access policies section and another is queue name; i.e. recharge
• In order to do the recharge, we need a mobile number, amount and operator from user
• Concatenate preceding three values separated with a star(*)
• Add Microsoft.Azure.ServiceBus from a NuGet package manager
• Create queue client using connection string and queue name
• Convert string message to Azure Service Bus message
• Using queue client, call SendAsync method to add a message in the queue.
• Call CloseAsync to close opened connection in finally block.
  
  1. class Program
  2. {
  3. static QueueClient queueClient;
  4. static void Main(string[] args)
  5. {
  6. string sbConnectionString = "Endpoint=sb://mobilerecharge.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=KVb9ubc9XaV0dT/1dMj/JGvVvUZ64U21IBI=";
  7. string sbQueueName = "Recharge";
  9. string messageBody=string.Empty;
  10. try
  11. {
  12. Console.WriteLine("-------------------------------------------------------");
  13. Console.WriteLine("Mobile Recharge");
  14. Console.WriteLine("-------------------------------------------------------");
  15. Console.WriteLine("Operators");
  16. Console.WriteLine("1. Vodafone");
  17. Console.WriteLine("2. Airtel");
  18. Console.WriteLine("3. JIO");
  19. Console.WriteLine("-------------------------------------------------------");
  21. Console.WriteLine("Operator:");
  22. string mobileOperator = Console.ReadLine();
  23. Console.WriteLine("Amount:");
  24. string amount = Console.ReadLine();
  25. Console.WriteLine("Mobile:");
  26. string mobile = Console.ReadLine();
  28. Console.WriteLine("-------------------------------------------------------");
  30. switch (mobileOperator)
  31. {
  32. case "1":
  33. mobileOperator = "Vodafone";
  34. break;
  35. case "2":
  36. mobileOperator = "Airtel";
  37. break;
  38. case "3":
  39. mobileOperator = "JIO";
  40. break;
  41. default:
  42. break;
  43. }
  45. messageBody = mobileOperator + "*" + mobile + "*" + amount;
  46. queueClient = new QueueClient(sbConnectionString, sbQueueName);
  48. var message = new Message(Encoding.UTF8.GetBytes(messageBody));
  49. Console.WriteLine($"Message Added in Queue: {messageBody}");
  50. queueClient.SendAsync(message);
  53. }
  54. catch (Exception ex)
  55. {
  56. Console.WriteLine(ex.Message);
  57. }
  58. finally
  59. {
  60. Console.ReadKey();
  61. queueClient.CloseAsync();
  62. }
  63. }
  64. }

• Run the application and provide the required inputs
• You can see the message 'Message Added in Queue…'