6.4SEDec 2, 2021
Systematically reviewing the layered architectural pattern principles and their use to reconstruct software architecturesAlvine B. Belle, Ghizlane El Boussaidi, Timothy C. Lethbridge et al.
Architectural reconstruction is a reverse engineering activity aiming at recovering the missing decisions on a system. It can help identify the components, within a legacy software application, according to the application's architectural pattern. It is useful to identify architectural technical debt. We are interested in identifying layers within a layered application since the layered pattern is one of the most used patterns to structure large systems. Earlier component reconstruction work focusing on that pattern relied on generic component identification criteria, such as cohesion and coupling. Recent work has identified architectural-pattern specific criteria to identify components within that pattern. However, the architectural-pattern specific criteria that the layered pattern embodies are loosely defined. In this paper, we present a first systematic literature review (SLR) of the literature aiming at inventorying such criteria for layers within legacy applications and grouping them under four principles that embody the fundamental design principles under-lying the architectural pattern. We identify six such criteria in the form of design rules. We also perform a second systematic literature review to synthesize the literature on software architecture reconstruction in the light of these criteria. We report those principles, the rules they encompass, their representation, and their usage in software architecture reconstruction.
2.8SEJun 3, 2019
Service-Oriented Re-engineering of Legacy JEE Applications: Issues and Research DirectionsHafedh Mili, Ghizlane El-Boussaidi, Anas Shatnawi et al.
Service-orientation views applications as orchestrations of independent software services that (1) implement functions that are reusable across many applications, (2) can be invoked remotely, and (3) are packaged to decouple potential callers from their implementation technology. As such, it enables organizations to develop quality applications faster than without services. Legacy applications are not service-oriented. Yet, they implement many reusable functions that could be exposed as \emph{services}. Organizations face three main issues when re-engineering legacy application to (re)use services: (1) to mine their existing applications for reusable functions that can become services, (2) to package those functions into services, and (3) to refactor legacy applications to invoke those services to ease future maintenance. In this paper, we explore these three issues and propose research directions to address them. We choose to focus on the service-oriented re-engineering of recent legacy object-oriented applications, and more specifically, on JEE applications, for several reasons. First, we wanted to focus on architectural challenges, and thus we choose to \textit{not} have to deal with programming language difference between source and target system. We chose JEE applications, in particular, because they embody the range of complexities that one can encounter in recent legacy applications, namely, multi-language systems, multi-tier applications, the reliance on external configuration files, and the reliance on frameworks and container services during runtime. These characteristics pose unique challenges for the three issues mentioned above.