Liquid Software: A New Paradigm for Networked Systems

This paper introduces the idea of dynamically moving functionality in a network-between clients and servers, and between hosts at the edge of the network and nodes inside the network. At the heart of moving functionality is the ability to support mobile code-code that is not tied to any single machine, but instead can easily move from one machine to another. Mobile code has been studied mostly for application-level code. This paper explores its use for all facets of the network, and in a much more general way. Issues of efficiency, interface design, security, and resource allocation, among others, are addressed. We use the term liquid software to describe the complete picture-liquid software is an entire infrastructure for dynamically moving functionality throughout a network. We expect liquid software to enble new paradigms, such as active networks that allow users and applications to customize the network by interjecting code into it.