Why nservicebus

It includes a reference to the NServiceBus NuGet package, which contains interfaces you can use to identify our messages. The interfaces aren't required, but they give us some extra validation from NServiceBus and allow the code to be self-documenting. The Ping class defines a message that the Sender sends to the Receiver. It's a simple C class that implements NServiceBus. ICommand , an interface from the NServiceBus package. This message is a signal to the reader and to NServiceBus that it's a command, although there are other ways to identify messages without using interfaces.

Pong is also a simple C object though this one implements NServiceBus. The IMessage interface represents a generic message that is neither a command nor an event, and is commonly used for replies. In our sample, it's a reply that the Receiver sends back to the Sender to indicate that a message was received.

The Ping and Pong are the two message types you'll use. The Sender is an endpoint that sends our Ping message. Here, you configure the Sender to use Azure Service Bus as the transport mechanism, then construct a Ping instance and send it. Hosting and logging are configured using standard Microsoft Generic Host options. For now, the endpoint is configured to run as a console application but it can be modified to run in Azure Functions with minimal changes, which we'll discuss later in this article.

Next, you tell the host to use NServiceBus with the. UseNServiceBus … extension method. The method takes a callback function that returns an endpoint that will be started when the host runs. In the endpoint configuration, you specify AzureServiceBus for our transport, providing a connection string from appsettings. Next, you'll set up the routing so that messages of type Ping are sent to an endpoint named "Receiver".

It allows NServiceBus to automate the process of dispatching the message to the destination without requiring the receiver's address. The call to EnableInstallers will set up our topology in the Azure Service Bus namespace when the endpoint is launched, creating the required queues where necessary. In production environments, operational scripting is another option to create the topology. The final piece of the sender is SenderWorker , a background service that is configured to send a Ping message every second.

The routing you configured in Sender specifies the destination of the Ping messages. It keeps the topology of the system which messages are routed to which addresses as a separate concern from the business code. The Sender application also contains a PongHandler.

Most of the problems that you encounter are caused by either DTC or not having enough disk space. Here is a blog post documenting how to troubleshoot DTC issues.

Disk space depends on the throughput of messages that flow through your system, their size, and the amount of time it takes to recover from a failure and start processing messages again. You should monitor disk space using performance counters. MSMQ comes with a command line utility — mqbkup — for backup and restore. Using this tool you can backup storage files, log files, transaction files, and Registry settings. With NServiceBus, concurrent access to an existing saga instance works out of the box.

This is because it relies on the underlying database system. With a coarse-grained lock you basically lock a group of entities together. Why would you need this? Two commands that would increase the quantity could be processed in parallel and break the invariant. This is because in each transaction, the invariant would hold and each transaction would commit, since they update different lines.

If we could lock the entire aggregate order and order lines , then the second transaction would fail and rollback, maintaining a consistent state. Framework designers usually make sure there is a way to decouple infrastructure code from business code. Usually this comes in the form of hooks that you can use you to inject custom code. NServiceBus has its own mechanisms that you can use. There are many use cases where these prove useful. Here are some examples:. Here are two approaches that can help you to keep the handlers clean of infrastructural concerns.

Every developer working on messaging solutions should read it. The authors do a good job on describing how you can combine the patterns together and present the trade-offs of different approaches. What endpoints are coupled to the X endpoint? What messages are part of the Y business flow? What messages is service Z sending? What messages trigger message W to be sent? Show me the entire message flow that starts with message W. While I was thinking about this, I saw this interesting tweet from Jack Kleeman that showed the communication paths between microservices at Monzo: microservices at monzo ; every line is an enforced network rule allowing traffic pic.

If cannot ship with Fan Courier, attempt to ship with Urgent Cargus. Idempotent Receiver One thing that you need to be mindful when retrying is message idempotency.

OrderId; Data. ShippingWithFanCourier; context. The long running process in this case handles two message: the OrderPlaced event — in which case it will send a ChargeCreditCardRequest the ChargeCreditCardRespone Implementation Since we only have two transitions, we could store the state in the Order entity.

The network is reliable Problem Calls over a network will fail. Solutions So, if calls over a network can fail, what can we do? Conclusion You might say that networks are more reliable these days — and they are.

Dead-Letter Queues When a message expires, the queue manager puts it in one of the dead letter queues. Performance Counters MSMQ provides performance counters that are helpful for monitoring its performance. Viewed 10k times. I've seen the thread on here about what a service bus is but it still hasn't clicked. Improve this question. GurdeepS GurdeepS Possible duplicate of What is a servicebus and when do I need one?

Add a comment. Active Oldest Votes. Benefits that NServiceBus will take care of include: Long-running stateful processes Using WF on top On-premise messaging Client can send messages if server is offline Poison message detection and dispatching Poison messages re-processing Subscriptions persist after restart Polymorphic message dispatch Polymorphic message routing Message-driven unit testing.

Improve this answer. Peter 7, 8 8 gold badges 57 57 silver badges 93 93 bronze badges. Kane Kane It can integrate with other systems via WCF that is hosted in the same process. Adam -- This is partly what's so confusing to those unfamiliar with service bus technology. Update coding-guidelines. Feb 13, Update init. Oct 23, Bump Microsoft. Sdk from Nov 8, GitHubSync update. Apr 24, GitHubSync update - master.