Reengineering legacy systems for distributed environments

Abstract

In the last decade, we have seen an increasing use of both the object-oriented paradigm and distributed systems. As a result, there is increasing interest in migrating and reengineering legacy systems to these new hardware technologies and software development paradigms. We define a reengineering environment that assists with the migration of legacy systems to distributed object environments. The reengineering environment includes the methodology and an integrated set of tools that support the implementation of the methodology. The methodology consists of multiple phases. First, we use reverse engineering techniques for program comprehension and design recovery. We then decompose the system into a hierarchy of subsystems by defining relationships between the entities of the underlying paradigm of the legacy system. The decomposition is driven by data mining, software metrics, and clustering techniques. Next, if the underlying paradigm of the legacy system is not object-based, we perform object-based adaptations on the subsystems. We then create components by wrapping objects and defining an interface. Finally, we allocate components to different sites by specifying the requirements of the system and characteristics of the network as an integer-programming model that minimizes the remote communication. We use middleware technologies for the implementation of the distributed object system.