FarGo: a system for mobile component-based application development

The design of efficient and reliable distributed applications that need to operate over various machines which are networked by wide area and/or low-bandwidth connections, demands new programming abstractions and mechanisms. In particular, the conventional static design-time determination of local-remote relationships between components implies that dynamic environmental changes are hard if not impossible to address without reengineering the application. The FARGO system presents a novel programming model that is centered around the concept of "dynamic application layout", which permits the manipulation of component location at runtime, thereby enabling to map dynamically the logical components onto physical hosts. Since the emphasis is on components that are part of a larger application (as opposed to "agents" that are often autonomous applications), component mobility preserves the validity of incoming and outgoing component references, in addition to the internal state of the component. Thus, FARGO inter-component references can dynamically stretch (i.e., become remote) and shrink (become local), unlike traditional references, which are fixed at design time to be either local or remote.