Delivery Confirmation

Delivery confirmation allows a publisher to verify that RabbitMQ accepted a message.

Use it when message loss is not acceptable.

---

Publish Flow

sequenceDiagram
    participant Publisher
    participant RabbitMQ

    Publisher->>RabbitMQ: Publish message
    RabbitMQ-->>Publisher: Ack / Nack

---

Descriptor

var descriptor = new PublisherBoundDescriptor
{
    Confirmation = new DeliveryConfirmation
    {
        Enabled = true,
        WaitFor = true,
        Timeout = TimeSpan.FromSeconds(30)
    },
    Exchanges =
    {
        new ExchangeBoundDescriptor
        {
            Name = "orders",
            Type = ExchangeTypes.Direct,
            Durable = true
        }
    }
};

---

Retry Hook

publisher.OnRetryFailed.Add(async args =>
{
    // Log or persist the failed publish attempt.
    await Task.CompletedTask;
});

---

When To Use

Enable delivery confirmation when:

• messages are business critical;
• auditability is required;
• publishing failures must be detected;
• the caller must know whether RabbitMQ accepted the message.

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Trade-Offs

Benefit	Cost
Better reliability	Lower throughput
Failure visibility	Extra latency
Stronger publish guarantees	More broker coordination

Delivery confirmation should be enabled deliberately, especially in high-throughput publishers.