Using an architectural approach to integrate heterogeneous, distributed software components

Many computer programs cannot be easily integrated because their components arc distributed and heterogeneous, i.e.. they are implemented in diverse programming languages, use different data representation formats, or their runtime environments are incompatible. In many cases, programs are integrated by modifying their components or interposing mechanisms that handle communication and conversion tasks. For example, remote procedure call (RPC) helps integrate heterogeneous, distributed programs. When configuring such programs, however, mechanisms like RPC must be used explicitly by software developers in order to integrate collections of diverse components. Each collection may require a unique integration solution. This paper describes improvements to the concepts of software packaging [1] and some of our experiences in constructing complex software systems from a wide variety of components in different execution environments. Software packagin8 is a prtr._s that automatically determines how to integrate a diverse collection of computer programs based on the types of components involved and the capabilities of available translators and adapters in an environment. Software packaging provides a context that relates such mechanisms to software integration processes and reduces the cost of configuring applications whose components are distributed or implemented in different programming languages. Our software packagin8 tool subsumes traditional integration tools like UNIX MAKE by providing a rule-based approach to software integration that is independent of execution environments. 1Supported by ARPA Grant MDA 972-9 l-J-102 under the DARPA Initiative for Concurrent Engineering (DICE) program, the National Library of Medicine (NLM) I-Iealtheare Information project, and NASA Grant NAG 5-2129 under the Independent Software Verification and Validation (IV&V) program. Formerly supported by ARPA Software Protoyping Technologies (Prototech) and Domain-Specifu: Software Architectures (DSSA) projects. 2Supported by ARPA Software Protoypin8 Technologies (Prototech) and Domain-Specific Software Architectures (DSSA) projects.