Startup and Shutdown Sequence

Component: NServiceBus
NuGet Package NServiceBus (6.x)

Code walk-through

Illustrates the order of startup shutdown operations including all extension points that plug into that process. So all interfaces that extend the startup and shutdown are included in an ExtensionPoints directory.

Logger

At each step in the process a line is written to both the console and a text file via a logger.

static class Logger
{
    static ILog log = LogManager.GetLogger(typeof(Logger));
    public static string OutputFilePath;
    static object locker = new object();

    static Logger()
    {
        OutputFilePath = Path.GetFullPath(@"..\StartupShutdownSequence.txt");
        AppDomain.CurrentDomain.ProcessExit += Exit;
        File.Delete(OutputFilePath);
        File.AppendAllText(OutputFilePath, "startcode");
        File.AppendAllText(OutputFilePath, " StartupShutdownSequence\r\n");
    }

    static void Exit(object sender, EventArgs e)
    {
        File.AppendAllText(OutputFilePath, "endcode");
    }

    public static void WriteLine(string message)
    {
        message = $"Thread:{Thread.CurrentThread.ManagedThreadId} {message}\r\n";
        log.Info(message);
        lock (locker)
        {
            File.AppendAllText(OutputFilePath, message);
        }
    }

}

Console Program

The main of the console Program configures and starts the bus while logging all these actions.

Logger.WriteLine("Starting configuration");
var endpointConfiguration = new EndpointConfiguration("Samples.StartupShutdown");
endpointConfiguration.EnableInstallers();
endpointConfiguration.EnableFeature<MyFeature>();
endpointConfiguration.UsePersistence<LearningPersistence>();
endpointConfiguration.UseTransport<LearningTransport>();

Logger.WriteLine("Calling Endpoint.Start");
var endpointInstance = await Endpoint.Start(endpointConfiguration)
    .ConfigureAwait(false);
// simulate some activity
await Task.Delay(500)
    .ConfigureAwait(false);

Logger.WriteLine("Endpoint is processing messages");
Logger.WriteLine("Calling IEndpointInstance.Stop");
await endpointInstance.Stop()
    .ConfigureAwait(false);
Logger.WriteLine("Finished");

The resulting order

In some versions of NServiceBus certain extension points are executed on separate threads.
Thread:1 Starting configuration
Thread:1 Calling Endpoint.Start
Thread:1 Inside INeedInitialization.Customize
Thread:1 Inside WantToRunBeforeConfigurationIsFinalized.Run
Thread:1 Inside Feature.Setup
Thread:1 Inside INeedToInstallSomething.Install
Thread:1 Inside FeatureStartupTask.OnStart
Thread:7 Endpoint is processing messages
Thread:7 Calling IEndpointInstance.Stop
Thread:7 Inside FeatureStartupTask.OnStop
Thread:7 Finished

Related Articles

  • Installers
    Installers ensure endpoint specific artifacts are installed and configured during endpoint startup.

Last modified