Main advantages include (but are not limited to): Takes care of serialization/deserialization of messages. Provides a neat model for dispatching messages w. handlers, polymorphic dispatch, arranging handlers in a pipeline etc. Handles unit of work. Provides a neat saga implementation. Gives you a host process that can be F5-debugged as well as installed as a … Read more
UPDATE: The licensing for NServiceBus seems to have changed for version 4.0. I can’t find anything about an Express Version. This mostly likely does not apply to that version. So I dug into this more for the 2.5 version of NServiceBus. NServiceBus has three licenses options (that apply to both code and binaries) that I … Read more
My solution is that you raise events in both Domain layer and service layer. Your domain: public class Order { public void ChangeStatus(OrderStatus status) { // change status this.Status = status; DomainEvent.Raise(new OrderStatusChanged { OrderId = Id, Status = status }); } public void AddNote(string note) { // add note this.Notes.Add(note) DomainEvent.Raise(new NoteCreatedForOrder { OrderId … Read more
It’s important to know that commands can be rejected after they are sent to the handler. At the very least, you could encounter a concurrency violation that cannot be detected until the aggregate root is touched. But also, the validation that can occur outside of the entity is simple validation. Not only string lengths, numeric … Read more
Publishing is used to notify multiple Subscribers of a particular event. A Publishing endpoint will have subscription storage to identify where to send messages to. Sending is typically used to issue a command to an endpoint. A command is telling the endpoint to do something and should not expect a reply(although you sometimes do want … Read more
I’m responsible for the Windows Azure ServiceBus support in NServicebus. And in my opinion this new Windows Server Servicebus provides the exact same capabilities as the Azure ServiceBus. So in my opinion it will be a good match with NServiceBus instead of a competitor (just as the Windows Azure ServiceBus is) and could be used … Read more
Years ago, I asked myself the same question. I was looking at NServiceBus to work with a different message queue, but the question was the same. I decided not to use NServiceBus. 6 Month later, I realized I had re-built half of what NServiceBus did… only much more poorly. The equivalent question of why would … Read more
If I had to summarize, here’s what I’d say: If you need commercial support, go for NServiceBus. If you’re comfortable with using forums as a means of support, MassTransit is a great option. The developers have been very responsive to our issues so far. If you choose MassTransit, now you will choose between MSMQ and … Read more
You can think of a service bus as the Ethernet of SOA. First and foremost, it introduces a language of identifying things, like an IP address in Ethernet. This name isn’t something inherently physical. Next, you have something physical involved on each node, like a queue in the case of a bus for supporting semi-connected … Read more
I’d recommend staying away from hand-rolled solutions as there is a bunch of somewhat difficult stuff that needs to be gotten just right – like how transactions are handled, how exceptions cause rollbacks, how to stop rolling back endlessly (poison messages), how to integrate with long-running workflows so that the state management boundaries line up, … Read more