Using Sensors to Detect Failures in a Loosely Integrated Heterogeneous Database System.
Wanlei Zhou · 1997
In this paper we apply the reactive system concepts in the design and implementation of a fault detection facility for a loosely integrated heterogeneous database system. The database system consists of a number of fully autonomous databases that, through their willingness, can share some portion of their information. Sensors #functions that expose some part of the state of an object# are placed on individual databases and system objects #such as traders, agents, and other sensors#. Other databases and system objects, and applications can subscribe to a sensor and therefore are noti#ed whenever the sensor value changes. The fault detection mechanism uses sensors to monitor individual databases and system objects and to detect database or system faults. Keywords: Distributed database systems, reactive systems, fault-tolerant computing, 1 Introduction A sensor is a system object of a reactive system that monitors an application's state and reports some aspects of the state to its sub...