LGF: A flexible framework for exposing legacy codes as services

Scientific applications, usually written in Fortran or C, need to be adapted to work in modern environments for conducting scientific computations, which are based on web services or components. This work presents a Legacy to Grid framework (LGF) which enables semi-automatic virtualization of legacy codes as grid services. In contrast to existing work, LGF goes beyond a simple adapter-pattern approach; it follows a two-tier design in which the adaptation service layer is loosely coupled with the legacy back end layer. We present the architecture of our framework, its basic operation, and its capabilities: support for different interaction patterns with a legacy code and for computation migration to enable fault-tolerance and dynamic load balancing of legacy codes. We also present a case study of our framework’s usage. We conclude with an evaluation of the impact of the two-layer architecture on the application’s performance and the tradeoff between flexibility and performance by measuring the overhead of virtualization for different granularities of the legacy code.