Modelling and Improving Group Communication in Server Operating Systems

virtual environment (DVE) have become increasingly popular. Many DVE implementations use a client-server architecture that requires the server to send the same data to all members of a collaborating or interacting group. This type of group communication operation is often implemented by sending data from the server to each recipient in a unicast fashion. The problem with this approach is that the cost of communication at the server does not scale very well with the number of participants because the application requires significant interaction with the operating system, network stack and drivers for each individual send. In this paper, we first propose a general analytic framework for predicting how group communication performance impacts DVE server capacity. We then conduct an experimental evaluation to determine the extent to which using a kernel-based group communication mechanism reduces the cost of group send operations. Lastly, we use the measurements obtained from these experiments to demonstrate how to apply the analytic framework by determining the extent to which the kernel-based group communication mechanism permits example applications to scale to more users.