Microsoft Azure Service Bus Basics And Understanding Topics And Queues

Azure Service Bus is a generic, Cloud-based messaging system. It connects apps running on Azure, on-premises systems or both. There are four different communication mechanisms of connection, each of which connects applications in a different way.

• Queues, allow one-directional communication. Each queue acts as an intermediary (broker) that stores sent messages until they are received. Each message is received by a single recipient.
  
  
• Topics, provids one-directional communication using subscriptions, a single topic can have multiple subscriptions. Like a queue, a topic acts as a broker, but each subscription can optionally use a filter to receive only messages that match specific criteria.
  
  
• Relays, provide bi-directional communication. Unlike queues and topics, a relay doesn't store messages. Instead, it just passes them on to the destination application.
  
  
• Event Hubs, is a highly scalable ingestion system that can process millions of events per second, enabling application to process and analyze the massive amounts of data produced by the connected devices and applications.

We can use one or more instances of four communication mechanisms depending on our requirement.

Reference - Azure Service Bus.

Creating Service Bus Namespace,

1. Log on to the Azure portal.
   
   
2. Click On New button. Select Hybrid Integration and select Service Bus.
   
   
   
   
3. Click on Create button at bottom.
   
   
   
   
4. Provide input as below and click Ok.
   
   

Using Service Bus Queue

Creating Service Bus Queue using Management Portal

1. Once created select Service Namespace and select Queue option.
   
   
2. Click on Create New Queue. Select Quick Create and provide the inputs.
   
   
   
   
3. Click Create A New Queue.

Creating Service Bus Queue programmatically

1. Open Visual Studio and create new console application.
   
   
2. In Solution Explorer, right-click References, then click Manage NuGet Packages.
   
   
3. Select the Microsoft Azure Service Bus item. Click Install.
   
   
4. Open App.confgig file, under appSettings you can see key for Connection String is added as below.
   
   1. <appSettings>
   2. <!-- Service Bus specific app setings for messaging connections -->
   3. <addkey="Microsoft.ServiceBus.ConnectionString"
   4. value="Endpoint=sb://[your namespace].servicebus.windows.net;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=[your secret]"/>
   6. </appSettings>
5. Go to Management portal. Click on Configuration Information button at bottom.
   
   
   
   
6. Copy the connection string and replace value of connectionString key in App.config file.
   
   
7. Write below code in program.cs file.
   
   Add the following references.
   
   1. using Microsoft.ServiceBus;
   2. using Microsoft.WindowsAzure;
   3. 
      

Add the following code in Main() method