Error handling & compensation

Activities fail — networks blip, label printers go offline. PgWorkflows retries activities for you, and when a workflow fails permanently partway through, ctx.OnFailure runs the compensations you registered, in reverse, so completed side effects get undone.

Activity retries

Compensation with ctx.OnFailure

Register a compensating activity right after the step it undoes. If a later step fails permanently, the registered compensations run.

var reservation = await ctx.Activity(
    (CheckoutActivities a) => a.ReserveInventory(input.UserName, itemName),
    cancellationToken
);

await ctx.OnFailure(
    (CheckoutActivities a) => a.ReleaseInventory(reservation.ReservationId),
    cancellationToken
);

var payment = await ctx.Activity(
    (CheckoutActivities a) => a.ChargePayment(input.UserName, input.Amount),
    cancellationToken
);

await ctx.OnFailure(
    (CheckoutActivities a) => a.RefundPayment(payment.PaymentId),
    cancellationToken
);

// If this throws permanently, the refund and the release both run.
await ctx.Activity(
    (CheckoutActivities a) => a.CreateShipment(input.UserName, itemName),
    cancellationToken
);

Workflow failure