Sample Usage

Change your Console app’s Main method to invoke AnankeRunner.Main, as such:

using Faithlife.Ananke;

class Program
{
  static void Main(string[] args) => AnankeRunner.Main(AnankeSettings.Create(), context =>
  {
    Console.WriteLine("Hello World!");
  });
}

There are three Ananke types used in this code:

1. The code creates an AnankeSettings object with the default settings. These settings control how Ananke behaves.
2. The code invokes AnankeRunner.Main, passing it the settings object and delegate representing the application logic.
3. The application logic now receives an AnankeContext object with its execution context.

Realistic Usage

Ananke passes a CancellationToken to your application logic called AnankeContext.ExitRequested. This token is cancelled whenever your application is requested to shut down. When ExitRequested is cancelled, your application logic should stop taking on new work, finish processing the current work it already has, and then return. If it does not do this, then its processing will be aborted when the application exits.

Ananke also passes an ILoggerFactory to your application logic called AnankeContext.LoggerFactory, which you can use to construct an ILogger and log to.

Finally, you should strongly consider setting AnankeSettings.MaximumRuntime. Giving this property a reasonable value will ensure your application will exit after a maximum amount of time. If your application is being orchestrated (e.g., in a Kubernetes Deployment), then you can set MaximumRuntime to create a “phoenix service” - one that periodically exits of its own free will and is then reborn by the orchestrator.

Taking these aspects into account, a more realistic example of Ananke usage is:

using Faithlife.Ananke;

class MyProgram
{
  private static readonly AnankeSettings Settings = AnankeSettings.Create(maximumRuntime: TimeSpan.FromHours(2));

  static void Main(string[] args) => AnankeRunner.Main(Settings, async context =>
  {
    // Normally loggers are created by dependency injection; this sample just creates it directly.
    var logger = context.LoggerFactory.CreateLogger<MyProgram>();

    while (true)
    {
      // Wait for the next work item to be available, and retrieve it.
      // If we are requested to exit, then cancel the wait.
      var workItem = await GetNextWorkItemAsync(context.ExitRequested);

      // Process the work item. Ignore requests to exit.
      logger.LogInformation("Processing {workItemId}", workItem.Id);
      ProcessWorkItem(workItem);
    }
  });
}

The actual shutdown time is randomly “fuzzed” a bit by default (see AnankeSettings.RandomMaximumRuntimeRelativeDelta). The default value for this is 0.1 (i.e., +/- 10%), so the actual maximum runtime of the code above will vary by +/- 12 minutes (10% of 2 hours), and be a random value between 1:48 and 2:12. This is just to avoid all applications from exiting at the exact same time, even if they were all started at the same time.