NotificationRetryBehavior

Namespace: RA.Utilities.Dispatcher.Behaviors

NotificationRetryBehavior<TNotification> is a notification behavior that retries a handler when it returns a failed result, with an incremental backoff.

📦 Type Definition

public class NotificationRetryBehavior<TNotification> : INotificationBehavior<TNotification>
    where TNotification : INotification
{
    public NotificationRetryBehavior(
        ILogger<NotificationRetryBehavior<TNotification>> logger,
        int maxRetries = 3,
        int baseDelayMilliseconds = 200);
}

Parameter	Default	Meaning
maxRetries	3	Maximum number of attempts (must be > 0)
baseDelayMilliseconds	200	Base delay; the actual delay per attempt is baseDelayMilliseconds * attempt (must be ≥ 0)

🎯 How It Works

1. Invokes next() — the inner pipeline (and ultimately the handler).
2. A failed result (or a thrown exception, which is captured into a failed result) triggers a retry after baseDelayMilliseconds * attempt delay.
3. Each failure is logged at Warning: [Notification Retry] Attempt {Attempt} failed for {NotificationType}. Retrying...
4. After maxRetries failed attempts it logs at Error ([Notification Retry] All {MaxRetries} attempts failed ...) and returns the last failed result.

The retry wraps the entire inner pipeline — including any behaviors registered inside it.

🚀 Usage

builder.Services
    .AddNotification<OrderPlaced>()
    .AddDecoration<NotificationRetryBehavior<OrderPlaced>>(); // defaults: 3 retries, 200 ms base delay

Custom configuration via DI registration:

builder.Services.AddTransient<INotificationBehavior<OrderPlaced>>(sp =>
    new NotificationRetryBehavior<OrderPlaced>(
        sp.GetRequiredService<ILogger<NotificationRetryBehavior<OrderPlaced>>>(),
        maxRetries: 5,
        baseDelayMilliseconds: 100));

🧠 Notes

• Latency — worst-case extra delay with 3 retries and 200 ms base is 200 + 400 + 600 = 1200 ms. Tune for your workload.
• Only failed results are retried — a successful handler runs once.
• Because the behavior is generic, the auto-registration generator reports DSAG010 and skips it — register it explicitly with AddDecoration.