Caveat: I realize this is potentially a server configuration question, but I thought there might be a programmatic answer, which is why I am posting here...
Running PHP on Apache, our users were able to issue multiple concurrent requests (from different tabs in the same browser, for example).
Since moving to FastCGI under IIS, this is no longer the default behavior. Now, when a user starts a request to the server and the browser is waiting for a response, if they open a new tab and start another request, the new request is not processed by IIS until the previous request is completed by IIS.
If the user opens a different browser and logs in (which starts a new session for that user), concurrent requests are possible.
My question is: is there a way to configure FastCGI/IIS7 that will allow multiple concurrent requests from the same user session? If not, is there an alternative that would allow this?