Leaky bucket model for autonomic control of distributed, collaborative systems

In recent years cloud computing has taken off and has become an underlying technology in many online applications and websites, whether using a private or public cloud. At the same time with the increase in globalization, online collaborative tools have become very important in order to allow different businesses to communicate with each other, or even different parts of the same company to communicate more easily and share data. Previous work introduced an architecture for a geographically distributed, cloud based collaboration application. While the architecture allowed the scaling up and down of the number of cloud instances being used to host media servers, no control scheme for such cloud scaling was provided. In this paper a model and control scheme for cloud scaling for a collaboration application is provided. The model is based on the leaky bucket model commonly used in network control, while the control system is a self-organizing system. A testbed for the architecture is also presented and used in order to gather performance data from the collaborative application.