Asynchronous operations from WCF service or ASP.NET

I'm developing an application using WCF Ria services and Silverlight. Performance and scalability is a must in this project. The problem is that I h开发者_运维百科ave to invoke several WCF services from RIA Service, and service invocation takes time. Threads are limited resource on the webserver, so when I invoke a service, the executing thread just hangs and waits for the answer. This is not acceptable in my sitation. I remember there was a way to workaround this issue back in .NET 2 days, I guess there is still now, but don't remember anything. Any memory refreshment would be nice :)

Thanks

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Looks like standard asynch pattern is the right way to go. Thanks to Ladislav Mrnka for pointing me to the right direction.