The objective of this project is to exercise the concepts of  network control. However, we'll be doing this at the user-level, perhaps with kernel support. The idea is to enable different classes of users, or different types of files to be transfered with differnt priorities, thus yielding different response times for the different requests. The motivation for such a scheme is that can be used by a web-enabled service provider that wants to differentiate the different types of users that it has, and therefore must give different priorities (at the network level, since this is the important external metric for the user) for different threads, different users, or different types of files.

The Apache server can be modified to include a registration procedure, or you can assume that users can register through a separate (regular) webpage. That is, you can assume you have a list of the "special" types of users, to expedite the project outcome.

One idea is to use netnice packet filters to identify the type of packet that is flowing and use netnice's network control mechanism to regulate how much data flows out from each Apache child process/thread. (See www.cs.pitt.edu/NETNICE or www.netnice.org for details.) For this to work, you'll have to install netnice in your FreeBSD machine and will have to understand how to use netnice for the network bandwidth control. netnice allows you to choose the type of scheduler you want to use, so that you can provide some type of fairness (stronger notion then simply the absence of starvation) among users.

Another idea is to modify Apache itself to make the coordination among child processes/threads, so that each process/thread regulates the amount of network packets it is using. The processes must have some form of coordination, so that they know what their "share" of the bandwidth is, and they must implement a packet scheduler that does not exceed this amount. Notice that this is not CPU scheduling, as the CPU will do very little processing and limiting the access of a process to the CPU will not have much effect in the overall response time of the processes.

You will have to test your program against a (real or synthetic) workload; a good start is traces that exist in the 'net, or a synthetic workload generator, such as WebStone. Alternatively, you may want to come up with your own workload generator and keep the files that will be transfered in the same location as your new Apache server.