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Explains how de-duplication can help to make sure a message is only delivered once within a certain time period, for more posts in this series go to Contents. In the posts atomic sends and send via I showed ways to achieve atomicity for a group of messages or messages that are sent out as part of an outgoing message. Let’s have a look at a piece of code that looks super simply but might always behave like you’d wish it should behave: public async Task<IActionResult>...

Explains how message sessions can be used to de-multiplex interleaved message streams and guaranteed ordered delivery, for more posts in this series go to Contents. Usually, when someone asks what the characteristics of a queue is most people would say First-in, first out. The thing is though with regular Azure Service Bus queues that is not guaranteed. Simply because you might do concurrent receive operations on the same queue or a message that failed processing will be handled later due to...

Explains where messages go when they can’t be transferred to the destination, for more posts in this series go to Contents. A while ago, I introduced the concept of deadlettering messages in which I talked about where messages go in case of message expiry, reaching the maximum delivery count, or they were forcefully dead lettered. In the posts about atomic sends as well as send via, I showed how a transaction scope can be used to group send operations together into atomic units that...

Shows how to query runtime information using the management client, for more posts in this series go to Contents. Quite early in this series I introduced the ManagementClient to create queues for example. Besides being able to create entities like queues, topics and subscriptions the management client provides the capability of querying runtime information from namespaces, queues, topics and subscriptions. The ability to query runtime information is quite handy for diagnostics purposes, check...

With SendVia, it is possible to create an atomic transaction between the incoming message and outgoing messages, for more posts in this series go to Contents. In scenarios where transactional processing is required for an incoming message that would generate some outgoing messages, the incoming and outgoing messages should all succeed or rollback. Failure to do so would either create duplicate processing (failure to complete the incoming message) or ghost messages (failure to revert the...

Shows how to batch multiple messages together into one single operation against Azure Service Bus, for more posts in this series go to Contents. In the article about atomic sends, we talked about the fact that each send operation executed against Azure Service Bus can fail and potentially has to be retried. Another important aspect though that wasn’t covered in the previous article is that every send operation has latency costs associated with it. Let’s assume we want to send ten...

Shows how to atomically send messages as a group, for more posts in this series go to Contents. This topic is best illustrated by directly diving into some code. var client = new QueueClient(connectionString, destination); var message = new Message(Encoding.UTF8.GetBytes("Deep Dive 1")); await client.SendAsync(message); message = new Message(Encoding.UTF8.GetBytes("Deep Dive 2")); await client.SendAsync(message); In the above code, a QueueClient is used to send two messages...

Shows how to create topologies by combining subscriptions with forwarding, for more posts in this series go to Contents. In the previous post we looked at how we can leverage topics and subscriptions together with rules to create powerful message-based solutions. A topic subscription resembles a virtual queue that receives copies of the messages that are sent to the topic. Messages are received from a subscription identically to the way they are received from a queue. The implication of the...

Shows how to publish and subscribe with topics, for more posts in this series go to Contents. In contrast to queues, in which a single consumer processes each message, topics and subscriptions provide a one-to-many form of communication, in a publish/subscribe pattern. The pattern is useful for scaling to large numbers of recipients, and each published message is made available to each subscription registered with the topic. The main benefits are: The publisher...

Introduces the concept of forwarding from one entity to another, for more posts in this series go to Contents. Queues and Subscriptions (more about those later) have the possibility to become what I call “forwarding-only” entities. An entity can be set into the forwarding mode by setting the property ForwardTo to a destination. var description = new QueueDescription("Hop"); await client.CreateQueueAsync(description); description = new QueueDescription("Hop0"); await client...