Azure Service Bus

Links

• Get started with Azure Service Bus topics and subscriptions
• Azure.Messaging.ServiceBus nuget package with exemple
• Azure Service Bus on ServerLess360

Description

It is a message broker with message queues and publish-subscribe topics.

Name	Description
Queue	Allows for Sending and Receiving of messages. Often used for point-to-point communication.
Topic	As opposed to Queues, Topics are better suited to publish/subscribe scenarios. A topic can be sent to, but requires a subscription, of which there can be multiple in parallel, to consume from.
Subscription	The mechanism to consume from a Topic. Each subscription is independent, and receives a copy of each message sent to the topic. Rules and Filters can be used to tailor which messages are received by a specific subscription.

Configure the service bus on Azure

• Azure portal → Service Bus → Add
• Create namespace: the namespace will be the url use by the service bus [namespace].servicebus.windows.net
• Pricing tiers: Basic, Standard (Topics), Premium (private network, dedicated capacity)
• Once deployed, go to the newly create service bus namespace
  • add queue
  • add topic then add subscription

Sender

Add Nuget package Azure.Messaging.ServiceBus

Program.cs

private const string ConnectionString = "get it from Azure Portal → Service Bus Namespace → Shared access policy → Primary Connection String"; private const string QueueName = "queue1"; static async Task Main(string[] args) { var client = new ServiceBusClient(ConnectionString); try // use await using in C# 8 / .Net Core { var sender = client.CreateSender(QueueName); var message = new ServiceBusMessage("Hello!"); await sender.SendMessageAsync(message); Console.WriteLine($"Sent {message.Body}"); } finally { await client.DisposeAsync(); } }

Receiver

Add Nuget package Azure.Messaging.ServiceBus

Program.cs

private const string ConnectionString = "get it from Azure Portal → Service Bus Namespace → Shared access policy → Primary Connection String"; private const string QueueName = "queue1"; static async Task Main(string[] args) { var client = new ServiceBusClient(ConnectionString); var processor = client.CreateProcessor(QueueName); try { processor.ProcessMessageAsync += MessageHandler; processor.ProcessErrorAsync += ErrorHandler; await processor.StartProcessingAsync(); Console.ReadKey(); } finally { await processor.DisposeAsync(); await client.DisposeAsync(); } } static async Task MessageHandler(ProcessMessageEventArgs args) { string body = args.Message.Body.ToString(); Console.WriteLine(body); // we can evaluate application logic and use that to determine how to settle the message. await args.CompleteMessageAsync(args.Message); } static Task ErrorHandler(ProcessErrorEventArgs args) { // the error source tells me at what point in the processing an error occurred Console.WriteLine(args.ErrorSource); // the fully qualified namespace is available Console.WriteLine(args.FullyQualifiedNamespace); // as well as the entity path Console.WriteLine(args.EntityPath); Console.WriteLine(args.Exception.ToString()); return Task.CompletedTask; }