A Process-Oriented Approach to Support Dynamic Evolution in Distributed Applications

Abstract

Dynamic evolution is beneficial and important to certain classes of distributed applications where shutdown is not always viable requiring modifications to such applications while they are executing. This paper describes Continuum, a process-oriented approach to address analysis and design aspects of dynamic evolution in software development, leveraging the flexibility of composition-based applications—like component-based and service-oriented ones—to facilitate dynamic changes. The approach begins with analyzing and extending the application lifecycle of an application to accommodate dynamic changes (i.e. while it is still executing). Then, the design of runtime modifications is carried out to progressively realize the changes, in terms of what to perform (i.e. transformations), who performs the transformations (i.e. transformation agents), and how the transformations are performed (i.e. transformation steps). A hypothetical electronic product catalogue application is used to illustrate Continuum.