The Ship Model for communication and mobility in distributed systems

The paper investigates a mechanism that allows distributed programs to reduce their network usage by moving code segments between computers. The idea of moving code is developed into an abstract model of distributed computation called the Ship Model that has a basic entity called a ship. Ships contain code and data and are somewhat like objects that can migrate. The term 'ship' is used to emphasize its mobility. The Ship Model uses mobility both as a way of moving code and data between machines and as an inter-ship communication mechanism. A prototype implementation written in C and running under Unix is constructed with test machines connected either by a high speed Ethernet network or a slow speed dialup line. A few example applications are implemented and tested under the prototype. Various measurements show that the Ship Model can provide increased performance both in the high and lour speed settings. Various issues regarding the implementation of the Ship Model are also discussed. >