A Scalability Model for Distributed Resource Management in Real-Time Online Applications

We consider a challenging class of highly interactive virtual environments, also known as Real-Time Online Interactive Applications (ROIA). Popular examples of ROIA include multi-player online computer games, e-learning and training based on real-time simulations, and other challenging applications. ROIA combine high demands on scalability and real-time user interactivity with the problem of an efficient and economic utilization of resources, which is difficult to achieve due to the changing number of users. This paper proposes a generic scalability model for ROIA that analyzes the application performance during runtime and predicts the demand for load balancing, i.e., when to add/remove resources or redistribute workload. We prove the practical relevance of the model by incorporating it into our RTF-RMS resource management system where it is used to predict the influence of different load-balancing actions on the application scalability. Our model is utilized by RTF-RMS for finding efficient load-balancing actions and thresholds for how often these actions should be applied. We report experimental results on the load balancing of a multi-player online game using predictions from the scalability model.