System Software Support for Mobile-Agent Computing

摘要

We investigated new system software architectures that support mobile code, based on network (and distributed) computing. The primary goal was to support an application's reliance on network resources, rather than local ones (which are often scarce in defense mobile-computing situations), to meet their communication and computational demands. We have developed a powerful extension of the client/server model, which we call the Extended Client/Server (ECS) model of distributed computing. Rather than a client sending requests to a server and receiving its reply as in the traditional client/server model, the client produces a mobile code object called an active extension, which then carries out the request/response interaction with the server. This active extension can execute at the server, at the client, or (most importantly) at another location where, presumably, it can interact with the server more advantageously (e.g., with higher performance, higher reliability, or higher security) than if it was co-located with the client We explored the design (and implementation) space for the ECS model, we completed multiple prototypes, implemented independently by different students, all of which provide basic support for remote computing, but each focusing on different areas of concern, such as security, resource allocation, client/agent and agent/server protocols, etc.