A QoS-Sensitive Approach for Timeliness and Freshness Guarantees in Real-Time Databases

Abstract

The demand for real-time database services has been increasing recently. Examples include sensor data fusion, decision support, web information services, e-commerce, online trading, and data-intensive smart spaces. A real-time database, a core component of many information systems for real-time applications, can be a main service bottleneck. To address this problem, we present a real-time database QoS management scheme that provides guarantees on deadline miss ratio and data freshness, which are considered two fundamental performance metrics for real-time database services. Using our approach, admitted user transactions can be processed in a timely manner and data freshness can be guaranteed even in the presence of unpredictable workloads and data access patterns. A simulation study shows that our QoS-sensitive approach can achieve a significant performance improvement, in terms of deadline miss ratio and data freshness, compared to several baseline approaches. Furthermore, our approach shows a comparable performance to the theoretical oracle that is privileged by the complete future knowledge of data accesses.