ContextErlang: A language for distributed context-aware self-adaptive applications

Abstract

Please cite this article in press as: G. Salvaneschi et al., ContextErlang: A language for distributed context-aware self-adaptive applications, Sci. Comput. Program. (2015), http://dx.doi.org/10.1016/j.scico. 2014.11.016 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ContextErlang AbstractSelf-adaptive software modifies its behavior at run time to satisfy changing requirements in a dynamic environment. Context-oriented programming (COP) has been recently proposed as a specialized programming paradigm for contextaware and adaptive systems. COP mostly focuses on run time adaptation of the application's behavior by supporting modular descriptions of behavioral variations. However, self-adaptive applications must satisfy additional requirements, such as distribution and concurrency, support for unforeseen changes and enforcement of correct behavior in the presence of dynamic change. Addressing these issues at the language level requires a holistic design that covers all aspects and takes into account the possibly cumbersome interaction of those features, for example concurrency and dynamic change. We present ContextErlang, a COP programming language in which adaptive abstractions are seamlessly integrated with distribution and concurrency. We define ContextErlang's formal semantics, validated through an executable prototype, and we show how it supports formal proofs that the language design ensures satisfaction of certain safety requirements. We provide empirical evidence that ContextErlang is an effective solution through case studies and a performance assessment. We also show how the same design principles that lead to the development of ContextErlang can be followed to systematically design contextual extensions of other languages. A concrete example is presented concerning ContextScala.

Event-driven Adaptation in COP

“…Differently from our proposal, it provides constructs to declare both the events thrown by an application and the transition rules specifying how to change the context when an event is received. The formal semantics of ContextErlang in [12] describes the behaviour of the constructs for adaptation within a distributed and concurrent framework. The messages of ContextErlang are similar to the our asynchronous event, and so is their handling.…”

Self-Adaptive Systems: A Systematic Literature Review Across Categories and Domains

“…Planning was a key component of this phase -automatic reconfiguration plans [203], adapting manager optimization [4], and plan generation techniques [66] all highlight the continued importance of forecasting in self-adaptive systems. Distributed techniques [233], fault localization [55], and architecture based self-adaptation [58] all were continued self-adaptive themes from the previous phase.…”

AErlang: Empowering Erlang with attribute-based communication

“…Erlang has been used as the host language for incorporating domain specific abstractions to deal with multi-agents and self-adaptive systems systems [28,13,33]. Among others, we mention ContextErlang [33] which is an extension of Erlang according to Context-Oriented Programming [21]. ContextErlang extends Erlang's gen_server behaviour with context_agent whose callback functions can be overridden by (functions implementing) variations at runtime.…”