Design, Implementation, and Evaluation of a QoS-Aware Real-Time Embedded Database
QeDB (Quality-aware real-time Embedded DataBase) is a database for data-intensive real-time applications running on embedded devices. Currently, databases for embedded systems are best effort, providing no guarantees on their timeliness and data freshness. Existing Real-Time DataBase (RTDB) technology cannot be applied to these embedded databases since it hypothesizes that the main memory of a system is large enough to hold the entire database. This, however, might not be true in data-intensive real-time applications. QeDB uses a novel feedback control scheme to support QoS in such embedded systems without requiring all data to reside in main memory. In particular, the authors' approach is based on simultaneous control of both I/O and CPU resources to guarantee the desired timeliness.