DRACON: QoS Management for Large-Scale Distributed Real-Time Databases
Woochul Kang, Sang Hyuk Son, John A. Stankovic · Journal of Software · 2009
Abstract—The demand for real-time data services is increasing in many large-scale distributed real-time applications including advanced traffic control, global environment control, and the nation-wide electric power grid control. However, providingquality-of-service(QoS)for dataservices in such large-scale and geographically distributed environment is a challenging task. In particular, both unpredictable communicational delays and computational workloads of large-scale distributed systems can lead to large number of deadline misses. We have designed a distributed real-time database architecture called DRACON (Decentralized data Replication And CONtrol), which enables QoS guarantees for large-scale distributed real-time applications. DRACON couples cluster-based replica-sharing and a decentralized control structure to address communication and computational unpredictability, simultaneously. The cluster-based replica-sharing mechanism not only enables scalable and bounded-delay access to remote data with high probability, but also decouples clusters to have less interaction, allowing a decentralized, thus scalable, QoS control structure. The simulation study demonstrates that DRACON’s decentralized QoS control structure combined with a decentralized replica-sharing structure provides robust and predictable QoS guarantees in a highly scalable manner. Index Terms—distributed real-time database, feedback control, data replication. I.