Stochastically timed predicate-based communication primitives for autonomic computing

TL;DR

This paper introduces a stochastically timed extension to predicate-based communication in autonomic systems, addressing design and semantics challenges, with formal semantics, modeling, and preliminary performance analysis.

Contribution

It presents a novel stochastically timed extension to SCEL, including formal semantics and application to a bike sharing system model.

Findings

Formal semantics for the extension are defined.

The language models a bike sharing system effectively.

Preliminary performance analysis is provided.

Abstract

Predicate-based communication allows components of a system to send messages and requests to ensembles of components that are determined at execution time through the evaluation of a predicate, in a multicast fashion. Predicate-based communication can greatly simplify the programming of autonomous and adaptive systems. We present a stochastically timed extension of the Software Component Ensemble Language (SCEL) that was introduced in previous work. Such an extension raises a number of non-trivial design and formal semantics issues with different options as possible solutions at different levels of abstraction. We discuss four of these options, of which two in more detail. We provide a formal semantics definition and an illustration of the use of the language modeling a bike sharing system, together with some preliminary analysis of the system performance.