Can I have two different clients listening to the same WCF callback and have them both receive the same data without having to do the processing twice?
+3
A:
Not really - at least not directly. What you're describing sounds a lot like the publish/subscribe pattern. A WCF service basically services one client and one client only, at any given time.
There are ways to do this in WCF 3.5 and better ones in WCF 4.0 - with or without Windows Azure's .NET Services. There are also other tools and support for the publish/subscribe pattern.
Check out things like:
- WCF Implementation of the Publish/Subscribe model
- Building a Pub/Sub Message Bus with WCF and MSMQ
- NServiceBus
If you Google or Bing for "WCF Publish Subscribe", you'll get a lot more hits - but those three should really get you started, I think.
marc_s
2010-06-30 19:36:42
@Marc: what if each client issues a request asking to be notified of the same event. Then, when the event occurs, the OP basically wants to do what .NET does when firing an event: call back each client with the event notification.
John Saunders
2010-06-30 19:39:12
+1
A:
In addition to the links @marc_s posted, you can also check out Juval Lowy's Publish/Subscribe Framework, which is shown graphically below.
.
This framework is described in detail in this MSDN article. And you can download the framework's source code for free at Lowy's website, IDesign.net.
Using the Pub/Sub Service allows the Publisher to publish the event once to a well-known endpoint. The Pub/Sub Service then takes care of publishing the notification to the subscribed clients.
Matt Davis
2010-06-30 19:43:10