I am performing a load test on a Sql Server (2008 sp3 Standard) environment. In order to simulate a high number of concurrent logins, there are 8 terminal servers each running 100 separate windows sessions. Each session is running a single instance of an application which logs onto it's own database on the SQL Server using a unique username for that session. The problem I am running into is after the ~250th login, the application cannot reach the SQL server anymore. Using management studio also yields same result. TCP and UDP ports are open. Telnet to port 1433 timeout. SQL logs don't even show it successfully or failing to log in.
I've made sure the Sql server is configure to unlimited concurrent connections. There's plenty of memory, CPU, network.
The only thing I can think of is SQL Server sees the 8 terminal servers and is blocking too many connections from a single PC although connecting with different users to different databases. Any insight would be appreciated.