A Protocol for the Atomic Capture of Multiple Molecules at Large Scale

TL;DR

This paper introduces a protocol for the atomic capture of molecules in large-scale distributed chemical programming systems, ensuring coherent reactions and efficient execution in dynamic environments.

Contribution

It presents a novel two-level protocol for atomic molecule capture in large-scale distributed platforms, addressing challenges of density and concurrency.

Findings

Protocol guarantees liveness of reactions.

Simulation shows high efficiency and low overhead.

Supports large-scale, dynamic distributed systems.

Abstract

With the rise of service-oriented computing, applications are more and more based on coordination of autonomous services. Envisioned over largely distributed and highly dynamic platforms, expressing this coordination calls for alternative programming models. The chemical programming paradigm, which models applications as chemical solutions where molecules representing digital entities involved in the computation, react together to produce a result, has been recently shown to provide the needed abstractions for autonomic coordination of services. However, the execution of such programs over large scale platforms raises several problems hindering this paradigm to be actually leveraged. Among them, the atomic capture of molecules participating in concur- rent reactions is one of the most significant. In this paper, we propose a protocol for the atomic capture of these molecules distributed and evolving over a large scale platform. As the density of possible reactions is crucial for the liveness and efficiency of such a capture, the protocol proposed is made up of two sub-protocols, each of them aimed at addressing different levels of densities of potential reactions in the solution. While the decision to choose one or the other is local to each node participating in a program's execution, a global coherent behaviour is obtained. Proof of liveness, as well as intensive simulation results showing the efficiency and limited overhead of the protocol are given.