You intentionally want to restrict or increase maximum request for one user for report server
There could be some scenario when one specific login has created too much connection on report server via some application, and creates an issue when the number of connection reaches a maximum limit which is called MaxActiveReqForOneUser. This parameter is defined in Rsreportserver.config file and the file is available a example D:\Program Files\Microsoft SQL Server\MSRS10.MSSQLSERVER\Reporting Services\ReportServer.
Open this file in any text editor and set the value to your choice and save the file.
<Add Key=”MaxActiveReqForOneUser” Value=”20″/>
In this way you can increase or restrict the number of request from one user.