Biztalk client defined subscription items

I am designing a Biztalk solution which requires client applications to subscribe and receive only a certain subset of event messages depending on their user permissions. Subscription will be done through topic or content based routing. The client will subscribe once and receive many messages until they choose to unsubscribe.

Client applications will number in the 100s and subscribed topics could change on a regular basis, so defining an individual send port from Biztalk for each reciever isn't a viable soluti开发者_Go百科on.

I have thought I could build an additional message broker service which holds the individual client subscriptions and distributes messages sent from a biztalk port.

I have also seen that a recipient list pattern can be build using orchestrations. This appears to me to still follow a request-response pattern though and I am after 1 way subscribe message to many returned event messages.

My message broker solution seems to me to be doubling up on what Biztalk should be good at so I imagine I am missing some important functionality somewhere. Has anyone tried such an application before and can give some pointers? Should I be investingating the ESB toolkit as a solution? I have had a look on the net but nothing makes it very clear for this type of topic-subscription model.

Thanks, Phil

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Do take a look at the ESB Toolkit. You can use the itinerary functionality that it adds to BizTalk, either with one of the built-in resolvers (e.g., UDDI) or with your own custom resolver. This allows you to route messages based on configuration (stored in Business Rules or elsewhere).

You will find a developer-oriented overview video of the ESB Toolkit on MSDN, which is a decent introduction to the design process and tooling. There are several other helpful videos there as well.

Your specific scenario can accomplished with a single itinerary, as described here. Use a receive pipeline with the ESB Dispatch Disassembler component, configure multiple resolvers, and for each resolver a new message is produced.

There are also two samples to look at:

1. The Itinerary On-Ramp Sample - builds a set of SOAP headers that contain the itinerary that you create in the test client, loads the specific message file from disk, appends the itinerary headers to the message, and submits it to the ESB through an Itinerary on-ramp for processing.
2. The Scatter-Gather Sample - Also appends SOAP headers containing the itinerary to the message, which is submitted to the ESB through an on-ramp for processing. A Broker orchestration analyzes the settings for its itinerary step, retrieves a collection of resolvers associated with the itinerary step, and for each of those resolvers resolves the service endpoint. After that, the orchestration activates the proper ServiceDispatcher orchestration instances to dispatch the outbound request messages.

You should also look at "How to: Route a Single Message to Multiple Recipients Using an Itinerary Routing Slip" or perhaps look into creating a custom itinerary message service (documentation is here).