Proceedings of International Workshop "Global Computing: Programming Environments, Languages, Security and Analysis of Systems"

According to the IST/ FET proactive initiative on GLOBAL COMPUTING, the goal is to obtain techniques (models, frameworks, methods, algorithms) for constructing systems that are flexible, dependable, secure, robust and efficient. The dominant concerns are not those of representing and manipulating data efficiently but rather those of handling the co-ordination and interaction, security, reliability, robustness, failure modes, and control of risk of the entities in the system and the overall design, description and performance of the system itself. Completely different paradigms of computer science may have to be developed to tackle these issues effectively. The research should concentrate on systems having the following characteristics: • The systems are composed of autonomous computational entities where activity is not centrally controlled, either because global control is impossible or impractical, or because the entities are created or controlled by different owners. • The computational entities are mobile, due to the movement of the physical platforms or by movement of the entity from one platform to another. • The configuration varies over time. For instance, the system is open to the introduction of new computational entities and likewise their deletion. The behaviour of the entities may vary over time. • The systems operate with incomplete information about the environment. For instance, information becomes rapidly out of date and mobility requires information about the environment to be discovered. The ultimate goal of the research action is to provide a solid scientific foundation for the design of such systems, and to lay the groundwork for achieving effective principles for building and analysing such systems. This workshop covers the aspects related to languages and programming environments as well as analysis of systems and resources involving 9 projects (AGILE , DART, DEGAS , MIKADO, MRG, MYTHS, PEPITO, PROFUNDIS, SECURE) out of the 13 founded under the initiative. After an year from the start of the projects, the goal of the workshop is to fix the state of the art on the topics covered by the two clusters related to programming environments and analysis of systems as well as to devise strategies and new ideas to profitably continue the research effort towards the overall objective of the initiative. We acknowledge the Dipartimento di Informatica and Tlc of the University of Trento, the Comune di Rovereto, the project DEGAS for partially funding the event and the Events and Meetings Office of the University of Trento for the valuable collaboration

Microservice Ambients: An Architectural Meta-modelling Approach for Microservice Granularity

Isolating fine-grained business functionalities byboundaries into entities called microservices is a core activityunderlying microservitization. We define microservitization asthe paradigm shift towards microservices. Determining theoptimal microservice boundaries (i.e. microservice granularity) is among the key microservitization design decisions thatinfluence the Quality of Service (QoS) of the microservice applicationat runtime. In this paper, we provide an architecturecentricapproach to model this decision problem. We build onambients - a modelling approach that can explicitly capturefunctional boundaries and their adaptation. We extend the aspect-oriented architectural meta-modelling approach of ambients-AMBIENT-PRISMA - with microservice ambients. A microservice ambient is a modelling concept that treatsmicroservice boundaries as an adaptable first-class entity. Weuse a hypothetical online movie subscription-based systemto capture a microservitization scenario using our aspectorientedmodelling approach. The results show the ability ofmicroservice ambients to express the functional boundary of amicroservice, the concerns of each boundary, the relationshipsacross boundaries and the adaptations of these boundaries. Additionally, we evaluate the expressiveness and effectivenessof microservice ambients using criteria from ArchitectureDescription Language (ADL) classification frameworkssince microservice ambients essentially support architecturedescription for microservices. The evaluation focuses on thefundamental modelling constructs of microservice ambientsand how they support microservitization properties such asutility-driven design, tool heterogeneity and decentralised governance. The evaluation highlights how microservice ambientssupport analysis, evolution and mobility/location awarenesswhich are significant to quality-driven microservice granularityadaptation. The evaluation is general and irrespective of theparticular application domain and the business competenciesin that domain

Step-wise development of resilient ambient campus scenarios

This paper puts forward a new approach to developing resilient ambient applications. In its core is a novel rigorous development method supported by a formal theory that enables us to produce a well-structured step-wise design and to ensure disciplined integration of error recovery measures into the resulting implementation. The development method, called AgentB, uses the idea of modelling database to support a coherent development of and reasoning about several model views, including the variable, event, role, agent and protocol views. This helps system developers in separating various modelling concerns and makes it easier for future tool developers to design a toolset supporting this development. Fault tolerance is systematically introduced during the development of various model views. The approach is demonstrated through the development of several application scenarios within an ambient campus case study conducted at Newcastle University (UK) as part of the FP6 RODIN project. © 2009 Springer Berlin Heidelberg

Adequacy Issues in Reactive Systems: Barbed Semantics for Mobile Ambients

Reactive systems represent a meta-framework aimed at deriving behavioral congruences for those specification formalisms whose operational semantics is provided by rewriting rules. The aim of this thesis is to address one of the main issues of the framework, concerning the adequacy of the standard observational semantics (the IPO and the saturated one) in modelling the concrete semantics of actual formalisms. The problem is that IPO-bisimilarity (obtained considering only minimal labels) is often too discriminating, while the saturated one (via all labels) may be too coarse, and intermediate proposals should then be put forward. We then introduce a more expressive semantics for reactive systems which, thanks to its flexibility, allows for recasting a wide variety of observational, bisimulation-based equivalences. In particular, we propose suitable notions of barbed and weak barbed semantics for reactive systems, and an efficient characterization of them through the IPO-transition systems. We also propose a novel, more general behavioural equivalence: L-bisimilarity, which is able to recast both its IPO and saturated counterparts, as well as the barbed one. The equivalence is parametric with respect to a set L of reactive systems labels, and it is shown that under mild conditions on L it is a congruence. In order to provide a suitable test-bed, we instantiate our proposal over the asynchronous CCS and, most importantly, over the mobile ambients calculus, whose semantics is still in a flux

A Uniform Approach to Programming the World Wide Web

We propose a uniform model for programming distributed Web applications. The model is based on the concept of Web computation places and provides mechanisms to coordinate distributed computations at these places, including peer-to-peer communication between places and a uniform mechanism to initiate computation in remote places. Computations can interact with the flow of HTTP requests and responses, typically as clients, proxies or servers in the Web architecture. We have implemented the model using the global pointers and remote service requests provided by the Nexus communication library. We present the model and its rationale, with some illustrative examples, and we describe the implementation

Microservice Transition and its Granularity Problem: A Systematic Mapping Study

Microservices have gained wide recognition and acceptance in software industries as an emerging architectural style for autonomic, scalable, and more reliable computing. The transition to microservices has been highly motivated by the need for better alignment of technical design decisions with improving value potentials of architectures. Despite microservices' popularity, research still lacks disciplined understanding of transition and consensus on the principles and activities underlying "micro-ing" architectures. In this paper, we report on a systematic mapping study that consolidates various views, approaches and activities that commonly assist in the transition to microservices. The study aims to provide a better understanding of the transition; it also contributes a working definition of the transition and technical activities underlying it. We term the transition and technical activities leading to microservice architectures as microservitization. We then shed light on a fundamental problem of microservitization: microservice granularity and reasoning about its adaptation as first-class entities. This study reviews state-of-the-art and -practice related to reasoning about microservice granularity; it reviews modelling approaches, aspects considered, guidelines and processes used to reason about microservice granularity. This study identifies opportunities for future research and development related to reasoning about microservice granularity.Comment: 36 pages including references, 6 figures, and 3 table

Agoric computation: trust and cyber-physical systems

In the past two decades advances in miniaturisation and economies of scale have led to the emergence of billions of connected components that have provided both a spur and a blueprint for the development of smart products acting in specialised environments which are uniquely identifiable, localisable, and capable of autonomy. Adopting the computational perspective of multi-agent systems (MAS) as a technological abstraction married with the engineering perspective of cyber-physical systems (CPS) has provided fertile ground for designing, developing and deploying software applications in smart automated context such as manufacturing, power grids, avionics, healthcare and logistics, capable of being decentralised, intelligent, reconfigurable, modular, flexible, robust, adaptive and responsive. Current agent technologies are, however, ill suited for information-based environments, making it difficult to formalise and implement multiagent systems based on inherently dynamical functional concepts such as trust and reliability, which present special challenges when scaling from small to large systems of agents. To overcome such challenges, it is useful to adopt a unified approach which we term agoric computation, integrating logical, mathematical and programming concepts towards the development of agent-based solutions based on recursive, compositional principles, where smaller systems feed via directed information flows into larger hierarchical systems that define their global environment. Considering information as an integral part of the environment naturally defines a web of operations where components of a systems are wired in some way and each set of inputs and outputs are allowed to carry some value. These operations are stateless abstractions and procedures that act on some stateful cells that cumulate partial information, and it is possible to compose such abstractions into higher-level ones, using a publish-and-subscribe interaction model that keeps track of update messages between abstractions and values in the data. In this thesis we review the logical and mathematical basis of such abstractions and take steps towards the software implementation of agoric modelling as a framework for simulation and verification of the reliability of increasingly complex systems, and report on experimental results related to a few select applications, such as stigmergic interaction in mobile robotics, integrating raw data into agent perceptions, trust and trustworthiness in orchestrated open systems, computing the epistemic cost of trust when reasoning in networks of agents seeded with contradictory information, and trust models for distributed ledgers in the Internet of Things (IoT); and provide a roadmap for future developments of our research

Directional Routing Techniques in VANET

Vehicle Ad hoc Networks (VANET) emerged as a subset of the Mobile Ad hoc Network (MANET) application; it is considered to be a substantial approach to the ITS (Intelligent Transportation System). VANETs were introduced to support drivers and improve safety issues and driving comfort, as a step towards constructing a safer, cleaner and more intelligent environment. At the present time vehicles are equipped with a number of sensors and devices, including On Board Units (OBU); this enables vehicles to sense situations affecting other vehicles and manage communications, by exploiting infrastructures such as the Road Side Unit (RSU); creating a Vehicle to Infrastructure (V2I) pathway, or interacting directly with other vehicles creating a Vehicle to Vehicle (V2V) pathway. Owing to the lack of infrastructures and difficulties involved in providing comprehensive coverage for all roads because of the high expense associated with installation, the investigation in this research concentrates on the V2V communication type rather than theV2I communication type. Many challenges have emerged in VANET, encouraging researchers to investigate their research in an attempt to meet these challenges. Routing protocol issues are considered to be a critical dilemma that needs to be tackled in VANET, particularly in a sparse environment, by designing an effcient routing mechanism that impacts on enhancing network performance in terms of disseminating messages to a desireddestination, balancing the generated packet (overhead) on the network and increasing the ratio of packet delivery with a reduced time delay. VANET has some unique characteristics compared to MANET; specifically it includes high mobility and constrained patterns restricted by roads, which lead to generation of a disconnected area occurring continuously between vehicles creating a Delay Tolerant Network (DTN). This is in opposition to applying the multi-hope technique properly to deliver the packet to its desire destination. The aim in this thesis comprises two main contributions. First developing novel routing protocols for a sparse environment in VANET with the context of utilising the mobility feature, with the aid of the equipped devices, such as Global Position System (GPS) and Navigation System (NS). This approach exploits the knowledge of Second Heading Direction (SHD), which represents the knowledge of the next road direction the vehicle is intending to take, in order to increase the packet delivery ratio, and to increase the route stability by decreasing instances of route breakage. This approach comprises two approaches; the first approach was designed for a highway scenario, by selecting the next hop node based on a filtration process, to forward the packet to the desired destination, while the second approach was developed for the intersection and roundabout scenario, in order to deliver the packet to the destination (unknown location). The formalising and specification of the VSHDRP has been performed using the CCA (Calculus of Context-aware Ambient), in order to evaluate the protocols behaviours, the protocol has been validated using the ccaPL. In addition the performance of the VSHDRP has been evaluated using the NS-2 simulator; comparing it with Greedy Perimeter Stateless Routing (GPSR) protocol, to reveal the strengths and weaknesses of the protocol. Second, developing a novel approach to broadcasting the HELLO beacon message adaptively in VANET based on the node's circumstances (direction and speed), in order to minimise the broadcasting of unnecessary HELLO beacon messages. A novel architecture has been built based on the adaptive HELLO beacon message, which clarifies how the OBU components are interacting with the connected sensors, in order to portray any changes in the vehicle's circumstances, so as to take the right decision to determine appropriate action. This architecture has been built based on the concept of a context aware system, which divides the architecture into three main phases; sensing processing and acting

Context-Aware Aided Parking Solutions Based on VANET

Vehicular Ad-hoc Network (VANET) is a special application of the Mobile Ad-hoc Network (MANET) for managing road traffic and substantially contributes to the development of Intelligent Transportation Systems (ITS). VANET was introduced as a standard for data communication between moving vehicles with and without fixed infrastructure. It aims to support drivers by improving safety and driving comfort as a step towards constructing a safer, cleaner and a more intelligent environment. Nowadays, vehicles are manufactured equipped with a number of sensors and devices called On Board Units (OBU) assisting the vehicle to sense the surrounding environment and then process the context information to effectively manage communication with the surrounding vehicles and the associated infrastructure. A number of challenges have emerged in VANET that have encouraged researchers to investigate this concept further. Many of the recent studies have applied different technologies for intelligent parking management. However, despite all the technological advances, researchers are no closer to developing a system that enables drivers to easily locate and reserve a parking space. Limited resources such as energy, storage space, availability and reliability are factors which could have contributed to the lack success and progress in this area. The task then is to close these gaps and present a novel solution for parking.This research intends to address this need by developing a novel architecture for locating and reserving a parking space that best matches the driver's preferences and vehicle profile without distracting the driver. The simple and easy-to-use mechanism focuses on the domain of an intelligent parking system that exploits the concept of InfoStation (IS) and context-aware system creating a single framework to locate and reserve a parking space. A three tier network topology comprising of vehicles, IS and the InfoStation Centre (ISC) has been proposed as the foundation of the on-street parking system architecture. The thesis attempts to develop the architecture of a parking management solution as a comfort-enhancing application that offers to reduce congestion related stress and improve the driver experience by reducing the time it takes to identify and utilise a parking space that is available.Saudi Arabia Cultural Bureau in U