title: What is the underlying mechanism to receive message in Azure Function Service Bus Queue Triggered functions?
body: <p>I understand that Azure Function - Azure Storage Queue triggered functions are triggered on a polling basis.</p>
  <p>But cant seem to find how it work for Azure Service Bus queues. Does it also follow the polling approach or has a session with the Azure Service Bus queue client that gets triggered whenever a message is sent into the queue (something like an event-driven approach)?</p>
  <p>Please refer to the following code:</p>
  <pre><code>[FunctionName(&quot;ServiceBusFunction&quot;)]
  public static void Run([ServiceBusTrigger(&quot;testQueueDuplicateDetection&quot;)] string myQueueItem, ILogger log)
  {
      log.LogInformation($&quot;C# ServiceBus queue trigger function processed message: {myQueueItem}&quot;);
  }
  </code></pre>