Azure PaaS Worker Role

The following sample assumes that you have created a new Azure Paas Cloud Service that contains a single empty Worker Role. The Cloud Service project templates are added to Visual Studio by installing the Azure .Net SDK.

The Worker Role implementation can be tested locally using the Azure Compute Emulator before deploying to the cloud. The MSDN Azure article "Using Emulator Express to Run and Debug a Cloud Service Locally" describes this in more detail.

The Azure PaaS Worker Role implementation is very similar to the Akka.Net Windows Service Sample. The quickest way to get started with Akka.Net is to create a simple Worker Role which invokes the top-level user-actor in the RunAsync() method, as follows:

WorkerRole.cs

using Akka.Actor;

namespace MyActorWorkerRole
{
    public class WorkerRole : RoleEntryPoint
    {
        private readonly CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
        private readonly ManualResetEvent runCompleteEvent = new ManualResetEvent(false);

        private ActorSystem _actorSystem;

        public override bool OnStart()
        {
            // Setup the Actor System
            _actorSystem = ActorSystem.Create("MySystem");

            return (base.OnStart());
        }

        public override void OnStop()
        {
            this.cancellationTokenSource.Cancel();
            this.runCompleteEvent.WaitOne();

            // Shutdown the Actor System
            _actorSystem.Shutdown();

            base.OnStop();
        }

        public override void Run()
        {
            try
            {
                this.RunAsync(this.cancellationTokenSource.Token).Wait();
            }
            finally
            {
                this.runCompleteEvent.Set();
            }
        }

        private async Task RunAsync(CancellationToken cancellationToken)
        {
            // Create an instance to the top-level user Actor
            var workerRoleActor = _actorSystem.ActorOf<WorkerRoleActor>("WorkerRole");

            // Send a message to the Actor
            workerRoleActor.Tell(new WorkerRoleMessage("Hello World!"));

            while (!cancellationToken.IsCancellationRequested)
            {
                await Task.Delay(1000);
            }
        }
    }
}