I am looking into making a real-time chat website, but have ran into a few questions before starting.
First off, we want to be able to have multiple people in one conversation and multiple conversations going on at the same time.
After doing some research, a lot of people suggested long-polling. Scalability sounds like a problem though, it seems like each user will have a connection waiting on the server and each connection uses its own thread. When there are multiple users this could cause performance problems. Most of the time when I read about this they were referring to Apache as the server though. Will I run into the same problem with IIS (6 or 7)? Roughly how many users could IIS handle before running into problems?
Is long-polling with ajax on IIS a good option for creating a real-time chat website or is there a different server that can handle the connections in a better way? Is there something else we should be looking into?