.Net Meanderings

I've been researching Yukon for a few months as I am writing a book on Yukon for O'Reilly. My co-author is Shawn Wildermuth (the ADO Guy).

My first real view of the product was at the Yukon Tech Preview in Seattle in Febrary 2003 and amongst all the things I already knew about (like XML integration and CLR hosting) one feature reallky caught my attention - the Service Broker (also known as SSB).

SSB is a reliable messaging infrastructure that is part of the database engine itself. It is built on top of the new Yukon queuing primitives and takes care of the complex parts of message orientated programming. Messages are sent to abstracted endpoints called Services. Services are bound to queues and specify the types of messages that they are prepared to receive - this is enforced by the Service Broker infrastructure.

To send a message to a service, a program starts a "Dialog" from one service (the initiator) to another (the target) and sends one or more messages to the target. These will be readable from the target service's queue only in the order they were sent - even if they were received in a different order - again, functionality that the Service Broker infrastructure provides.The program (most likely a stored procedure) that reads the target queue can send messages back on the same dialog to the initiating service.

The programs that service queues (sometimes calls Service Programs) can be autostarted by SSB and in fact multiple copies can be started if the queue readers aren't keeping up with the rate messages are received.

Anyway, I'll leave it there for now and post some more (including syntax) shortly.