ECA rule processing in distributed and heterogeneous environments

Abstract

Active systems have been proposed as a paradigm to satisfy the needs of many databases and other applications that require a timely response to situations. Event-Condition-Action (or ECA) rules (S. Chakravarthy et al., 1989) are used to capture the active capability in a system. The utility and functionality of active capability (ECA roles) has been well established in the context of databases. In order for the active capability to be useful for a large class of advanced applications, it is necessary to go beyond what has been proposed/developed in the context of databases. Specifically, extensions beyond the current state of the art in active capability are needed along several dimensions: i) make the active capability available for non-database applications, in addition to database applications; ii) make the active capability available in distributed environments; and iii) make the active capability available for heterogeneous sources of events (whether they are databases are not). The objective of the paper is to provide an architecture and framework to support ECA rules for distributed and heterogeneous systems. We describe the design of our ECA rule service, the alternatives considered at each step and the reasons for our choice of a particular alternative. Finally we draw conclusions about the architecture of our system and the utility of our system for a wide range of applications.