Tomasz Janczuk has published one really nice blog post on Silverlight PolingHttpPushBinding usage.
In my recent articles I have introduced a sample pub/sub application using Silverlight’s HTTP polling duplex protocol, an AJAX client talking the same protocol, as well as discussed server side performance of the protocol. The latter post pointed out scalability challenges associated with deploying a WCF service using the Silverlight HTTP polling duplex protocol in a web farm scenario. This article introduces one possible solution to the scale-out problem, enabling an applications utilizing the protocol to accommodate an arbitrary number of concurrent clients through scale-out of the backend infrastructure.