language: en

MDARTS: A Multiprocessor Database Architecture for Real-Time Systems

Real-Time Computing Laboratory Computer Science and Engineering Division Department of Electrical Engineering and Computer Science The University of Michigan
Ann Arbor, Michigan 48109-2122

[(313) 763-0391]

ABSTRACT Some of the advanced real-time systems being proposed, such as the Next Generation Workstation/Machine Controller (NGC) for automated factories, require a built-in database to support concurrent data access and provide well-defined interfaces between software modules. However, conventional database systems do not provide the performance levels or response time guarantees needed by real-time applications. To address the need for high-performance real-time database systems, we propose to design, implement, and evaluate an object-oriented software system called Multiprocessor Database Architecture for Real-Time Systems (MDARTS). An important feature of MDARTS is that it supports explicit specification of real-time requirements and semantic constraints at an object-granularity level. The database examines these specifications at runtime during application initialization and dynamically adjusts its data management strategy accordingly to provide hard real-time guarantees. For maximum performance on shared-memory multiprocessors, MDARTS supports concurrent, direct, shared-memory data access. Prior real-time database systems do not support per-object dynamic configuration during initialization, and they either work only on uniprocessors or use relatively slow inter-process communication for all transactions. The unique design of MDARTS will support a transaction execution time two to three orders of magnitude faster than current real-time database systems for multiprocessors. For data access with less stringent timing constraints, MDARTS also supports remote transactions across networks and provides interfaces to external database systems. Once we have implemented the basic MDARTS architecture, we will demonstrate its capabilities by using it to develop distributed, open architecture controllers for actual manufacturing machine tools.