Skip to main content

Delivery Result

Every send operation returns a DeliveryResult containing metadata about the produced message.

Result Properties​

var result = await messageBus.SendAsync("orders", message);

// Topic and partition info
Console.WriteLine($"Topic: {result.Topic}");
Console.WriteLine($"Partition: {result.Partition.Value}");
Console.WriteLine($"Offset: {result.Offset.Value}");

// Timestamp
Console.WriteLine($"Timestamp: {result.Timestamp.UtcDateTime}");

// Key used for the message
Console.WriteLine($"Key: {result.Key}");

// Delivery status
Console.WriteLine($"Status: {result.Status}");

// Access the original message
Console.WriteLine($"Message: {result.Message.Value}");
Console.WriteLine($"Headers: {result.Message.Headers}");

Delivery Status​

The Status property indicates whether the message was persisted:

StatusDescription
PersistedMessage was successfully written to Kafka
PossiblyPersistedMessage may or may not have been written
NotPersistedMessage was not written to Kafka
var result = await messageBus.SendAsync("orders", message);

switch (result.Status)
{
    case PersistenceStatus.Persisted:
        logger.LogInformation("Message delivered successfully");
        break;
    case PersistenceStatus.PossiblyPersisted:
        logger.LogWarning("Message delivery uncertain");
        break;
    case PersistenceStatus.NotPersisted:
        logger.LogError("Message delivery failed");
        break;
}

Batch Results​

When sending batches, you receive a collection of results:

var messages = new[] { message1, message2, message3 };
var results = await messageBus.SendBatchAsync("orders", messages);

foreach (var result in results)
{
    if (result.Status == PersistenceStatus.Persisted)
    {
        logger.LogInformation(
            "Delivered to P:{Partition} O:{Offset}",
            result.Partition.Value,
            result.Offset.Value
        );
    }
    else
    {
        logger.LogWarning(
            "Delivery uncertain: {Status}",
            result.Status
        );
    }
}

// Summary
var succeeded = results.Count(r => r.Status == PersistenceStatus.Persisted);
var total = results.Count();
logger.LogInformation("Delivered {Succeeded}/{Total} messages", succeeded, total);

Extracting Message ID​

Use the offset as a unique message identifier:

public class OrderService(IMessageBus messageBus)
{
    public async Task<long> CreateOrderAsync(Order order)
    {
        var result = await messageBus.SendAsync("orders", order);

        // Return offset as message ID
        return result.Offset.Value;
    }
}

Error Handling​

Handle delivery failures gracefully:

public async Task<bool> TrySendAsync<T>(string topic, T message)
{
    try
    {
        var result = await messageBus.SendAsync(topic, message);

        if (result.Status != PersistenceStatus.Persisted)
        {
            logger.LogWarning(
                "Message to {Topic} may not be persisted: {Status}",
                topic,
                result.Status
            );
            return false;
        }

        return true;
    }
    catch (ProduceException<string, T> ex)
    {
        logger.LogError(ex, "Failed to produce message to {Topic}", topic);
        return false;
    }
}

Next Steps​