Mobile Code for Coordination

An effective coordination mechanism is central to building large distributed systems. Overcoming limitations of a coordination language can be a major challenge for developers of distributed systems. This paper presents a novel coordination mechanism based on code mobility. In this mechanism coordination is realised by exchanging pieces of mobile code between coordinated entities. This approach overcomes constrains of a statically defined coordination language by allowing coordinated entities to dynamically redefine coordination rules and use all the power of a programming language to express such rules. This helps to implement sophisticated and efficient data retrieval and processing algorithms and also reduce network traffic. The paper also discusses a non-language based coordination framework specially developed to support coordination based on mobile code and a pragmatic solution to the problem of protecting hosts from potentially harmful mobile code. A proof of concept implementation demonstrates the feasibility and applicability of the proposal.