A Causal Order Control Method in Large-Scale Continuous Multimedia Systems

Preserving causal order consistency is one of the key issues in large-scale continuous multimedia systems. Most existing causal order algorithms can merely function well without considering message lifetime restriction. However, the ignore of message lifetime may cause some serious problems, since the continuous multimedia systems aim to achieve a sufficiently realistic representation on simulating the real world where events happen in real-time and the causal relationship between events should be maintained completely within messages lifetimes. In this paper, we propose a novel lifetime-restricted causal order (LRCO) control method which could evaluate the network state, predict the message transport latency and distributedly maintain causal order consistency between timely events. Moreover, the communication overhead of LRCO is irrelevant to the system scale and is adaptive to the network latency. The experiment results show that LRCO is a scalable, light-weight control method that can preserve causal order consistency efficiently within the messages lifetimes.