Polling duplex does not scale... what's the alternative?

Question

Our tests showed that the polling duplex binding simply does not scale and can not be used on a service within a web-farm or even a web garden. We have looked at TCP/IP sockets for a client push method, but the firewall issue is does allow us to use sockets.

I was wondering what is the alternative "free" solution to this problem? allowing us to scale and allowing us to push data to client...

I have also tried the solution in this article http://tomasz.janczuk.org/2009/09/scale-out-of-silverlight-http-polling.html but at the end, there was too much polling on a database, and performance was affected.

Our Silverlight application need a pub/sub design, but it needs to be reliable and scalable... any ideas?

Answer 1

I heard about lightstreamer, which scales very well , but I´m not shure about license fees

Also have a look at this intresting conversation at silverlight.net

Answer 2

Check out WebSync, it's a full comet server built for .NET. It handles server farms, and over 30,000 simultaneous users per server on commodity hardware (3 gig ram, cheap AMD 3 core processor). It's not free, but it's a great solution. There's even an example running silverlight here.