If a polling duplex service co-exists with normal WCF service on the same IIS web application, the WCF service might be significantly slowed sometimes. In this post, the Silverlight Web Services team shows the process of resolving this issue.
The first thing we have to do is to create some code that reproduces the issue. After contacting customers to get there scenarios and settings, we are able to create a test Silverlight application and ASP.Net web application that consistently reproduce this issue (see attached probject). Our test application has two client proxies, one polling duplex based stock ticker and one normal BasicHttpBinding-based calculator. Once the xap is loaded, calculator proxy will start continuously calling the “Add” method of the calculator.