DotNetify.LoadTester 1.0.2

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DotNetify-LoadTester

DotNetify-LoadTester is a tool for authoring and running performance testing on your dotNetify application servers. It allows you to establish thousands of concurrent SignalR connections to your dotNetify hub and write tests that emulate how your application clients interact with the server-side view models.

Installation

Create a .NET Core test or console app project and add the following library from NuGet: DotNetify.LoadTester.

Basic Usage

Start by creating a new instance of LoadTestBuilder and configure the application server URL, the number of clients, and how each one will interact with your server-side view model:

var builder = new LoadTestBuilder("https://my-app.io")
  .AddClient(5, (client, index) =>
  {
    client.Connect(nameof(HelloWorldVM));
  });

The AddClient method allows to configure the behaviors of each client through the delegate argument of type ILoadTestClientBuilder. In the above example, all clients will attempt to connect to the HelloWorldVM view model at the specified URL when the test commences. And just as the real API, you can pass connect options to the Connect method.

Run the load test by calling the RunAsync method with the run duration as its argument:

await builder.RunAsync(TimeSpan.FromMinutes(5));

You can configure how fast the clients get added or disposed with the SetRampUpPeriod and SetRampDownPeriod methods:

await builder
  .SetRampUpPeriod(TimeSpan.FromSeconds(30))
  .SetRampDownPeriod(TimeSpan.FromSeconds(30))
  .RunAsync(TimeSpan.FromMinutes(5));

Without the configuration, the interval defaults to 100 milliseconds between clients.

Logging

It's always a good idea to pass a logger so you can access the information generated by the test runner such as when the clients are connecting, when they are being disposed, or if there are connection errors:

ILogger logger = LoggerFactory
  .Create(builder => builder.AddConsole())
  .CreateLogger("MyLoadTest");

await builder
  .SetLogger(logger)
  .RunAsync(TimeSpan.FromMinutes(5));

Client Dispatch

To get the clients to dispatch data following a successful connection, use the Dispatch method. You can specify the frequency, either once or repeating with time delay in milliseconds, and use the Wait method to add delay between different dispatches:

var builder = new LoadTestBuilder("https://my-app.io")
  .AddClient(5, (client, index) =>
  {
    client
      .Connect(nameof(HelloWorldVM))
      .Dispatch(new { Greetings = "Hello" }).Once()
      .Wait(5000)
      .Dispatch(new { Greetings = "World" }).Repeat(3, 1000);
  });

The Dispatch method has an overload that allows you to pass a callback function to build the dispatch payload at runtime:

   client.Dispatch(_ => new { Time = DateTime.Now }).RepeatContinuosly(1000);

Handling Server Responses

When you want to inspect the responses a client receives, and perhaps perform dispatches according to those responses, use the OnServerResponse method:

   client
    .Connect(nameof(EchoVM))
    .OnServerResponse((vm, response) =>
    {
      var deserializedResponse = response.As<EchoPing>();
      vm.Dispatch(new { Pong = deserializedResponse.Ping.Time });
    });

The method parameter is an action delegate which passes two arguments: an object of type IClientVM that will allow you to perform a dispatch, and the server response itself, wrapped in an object of type ServerResponse. You can access the raw data directly, or use a convenient As method to deserialize the data into a strongly-typed object.

Client Destroy

To remove a client's connection to the view model, use the Destroy method provided by both the ILoadTestClientBuilder and the IClientVM types.

To receive callback when the event occurs, use the OnDestroyed method of ILoadTestClientBuilder.