The Silverlight report viewer control never clears the cache out of the database. Steps to reproduce:

1. Configure the database cache provider with mssql as defined in the documentation.

2. View a report by setting the Report property of the viewer with the class name of the report.

3. Clear the report when the user is done viewing the report by setting the Report property of the viewer to null.

I see the request to invalidate the report session, but the cached data remains in the database. 

Raw request:
 <s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"><s:Body><RenderAndCache xmlns="Telerik.ReportService"><format></format><report></report><deviceInfo xmlns:d4p1="http://schemas.microsoft.com/2003/10/Serialization/Arrays" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"><d4p1:KeyValueOfstringanyType><d4p1:Key>InvalidSessions</d4p1:Key><d4p1:Value xmlns:d6p1="http://www.w3.org/2001/XMLSchema" i:type="d6p1:string">["035e4409-655c-49ab-a5b0-b9bf5e0d9859"]</d4p1:Value></d4p1:KeyValueOfstringanyType></deviceInfo><parameters xmlns:d4p1="http://schemas.microsoft.com/2003/10/Serialization/Arrays" i:nil="true" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" /></RenderAndCache></s:Body></s:Envelope>