Testing the robustness of controllers for self-adaptive systems

Self-Adaptive systems are software-intensive systems endowed with the ability to respond to a variety of changes that may occur in their environment, goals, or the system itself, by adapting their structure and behavior at run-time in an autonomous way. Controllers are complex components incorporated in self-adaptive systems, which are crucial to their function since they are in charge of adapting the target system by executing actions through effectors, based on information monitored by probes. However, although controllers are becoming critical in many application domains, so far very little has been done to assess their robustness. In this paper, we propose an approach for evaluating the robustness of controllers for self-adaptive software systems, aiming to identify faults in their design. Our proposal considers the stateful nature of the controller, and identifies a set of robustness tests, which includes the provision of mutated inputs to the interfaces between the controller and the target system (i.e., probes). The feasibility of the approach is evaluated on Rainbow, a framework for architecture-based self-adaptation, and in the context of the Znn.com case study

Robustness-Driven Resilience Evaluation of Self-Adaptive Software Systems

An increasingly important requirement for certain classes of software-intensive systems is the ability to self-adapt their structure and behavior at run-time when reacting to changes that may occur to the system, its environment, or its goals. A major challenge related to self-adaptive software systems is the ability to provide assurances of their resilience when facing changes. Since in these systems, the components that act as controllers of a target system incorporate highly complex software, there is the need to analyze the impact that controller failures might have on the services delivered by the system. In this paper, we present a novel approach for evaluating the resilience of self-adaptive software systems by applying robustness testing techniques to the controller to uncover failures that can affect system resilience. The approach for evaluating resilience, which is based on probabilistic model checking, quantifies the probability of satisfaction of system properties when the target system is subject to controller failures. The feasibility of the proposed approach is evaluated in the context of an industrial middleware system used to monitor and manage highly populated networks of devices, which was implemented using the Rainbow framework for architecture-based self-adaptation

Towards robustness and self-organization of ESB-based solutions using service life-cycle management

Enterprise Service Bus (ESB) is a middleware infra-structure that provides a way to integrate loosely-coupled heterogeneous software applications based on the Service Oriented Architecture principles. The life-cycle management of services in such highly changing environments is a critical issue for the component’s reuse, maintenance and operation. This work introduces a service life-cycle management module that extends the traditional functionalities with advanced monitoring and data analytics to contribute for the robustness and self-organization of networks of clusters based on ESB platforms. The realization of this module was embedded in the JBoss ESB, considering a sniffer mechanism to collect relevant details of the service messages crossing the bus. A Liferay portal was created to display information related to the services’ health.Um Barramento de Serviços (BS) é um middleware que oferece uma infraestrutura que permite a integração de aplicações heterogéneas, com base nos princípios das Arquiteturas Orientadas aos Serviços. A gestão do ciclo de vida dos serviços em tais ambientes altamente dinâmicos é um problema crítico com impacto na operação e manutenção do sistema, bem como na capacidade de reutilização de componentes. Este trabalho apresenta um módulo de gestão do ciclo de vida de serviços, que acrescenta às funcionalidades tradicionais a monitorização avançada e a análise de dados, no sentido de contribuir para a robustez e auto-organização de redes de agregados computacionais baseados em plataformas BS. O módulo foi integrado no JBoss ESB e utilizou-se um sniffer para recolher os detalhes das mensagens que se encontram a ser trocadas no barramento. Foi criado um portal Liferay para apresentar a informação relativa à saúde dos serviços.This work was supported by the European Union FP7 Programme under the ARUM project No. 31405

Ordering, timeliness and reliability for publish/subscribe systems over WAN

In the last few years, the increasing use of the Internet and geo-political, sociological and financial changes induced by globalization, are paving the way for a connected world where the information is always available at the right place and the right time. As such, applications previously deployed for ``closed'' environmets, are now federating into geographically distributed systems connected through a Wide Area Network (WAN). By this evolution, in the near future no system will be isolated: every system will be composed by interconnected systems, i.e., it will be a System of Systems (SoS). Example of SoS are the Large-scale Complex Critical Infrastructure (LCCIs), such as power grids, transport infrastructures (airports and seaports), financial infrastructures, next generation intelligence platforms, to cite a few. In these systems, multiple sources of information generate a high volume of events that need to be delivered to all intended destinations by respecting several Quality of Service (QoS) constraints imposed by the critical nature of LCCIs. As such, particular attention is devoted to the middleware solution used to disseminate information in the SoS. Due to its inherently scalability provided by space, time and synchronization decoupling properties, the publish/subscribe paradigm is becoming attractive for the implementation of a middleware service for LCCIs. However, scalability is not the only requirement exhibited by SoS. Several services need to control a broader set of QoS requirements, such as timeliness, ordering and reliability. Unfortunately, current middleware solutions do not address QoS constraints required by SoS. Current publish/subscribe middleware solutions for the WAN environment offer only a best effort event dissemination, with no additional control on QoS. Just a few implementations try to address some isolated QoS policy, making them not suitable for a SoS scenario. The contribution of this thesis is to devise a QoS layer that can be posed on top of a generic publish/subscribe middleware that enriches its service by addressing: (i) ordering, (ii) reliability and (iii) timeliness in event dissemination in SoS over WAN. Specifically, we first analyze several real case studies, by highlighting their QoS requirements in terms of ordering, reliability and timeliness, and compare these requirements with both current research prototypes and commercial systems. Then, we fill the gap by proposing novel algorithms to address those requirements. The proposed protocols can also be combined together in order to provide the QoS level required by the particular application. In this way, QoS issues do not need to be addressed at application level, so as to leave applications to implement just their native functionalities

Ordering, timeliness and reliability for publish/subscribe systems over WAN

In the last few years, the increasing use of the Internet and geo-political, sociological and financial changes induced by globalization, are paving the way for a connected world where the information is always available at the right place and the right time. As such, applications previously deployed for ``closed'' environmets, are now federating into geographically distributed systems connected through a Wide Area Network (WAN). By this evolution, in the near future no system will be isolated: every system will be composed by interconnected systems, i.e., it will be a System of Systems (SoS). Example of SoS are the Large-scale Complex Critical Infrastructure (LCCIs), such as power grids, transport infrastructures (airports and seaports), financial infrastructures, next generation intelligence platforms, to cite a few. In these systems, multiple sources of information generate a high volume of events that need to be delivered to all intended destinations by respecting several Quality of Service (QoS) constraints imposed by the critical nature of LCCIs. As such, particular attention is devoted to the middleware solution used to disseminate information in the SoS. Due to its inherently scalability provided by space, time and synchronization decoupling properties, the publish/subscribe paradigm is becoming attractive for the implementation of a middleware service for LCCIs. However, scalability is not the only requirement exhibited by SoS. Several services need to control a broader set of QoS requirements, such as timeliness, ordering and reliability. Unfortunately, current middleware solutions do not address QoS constraints required by SoS. Current publish/subscribe middleware solutions for the WAN environment offer only a best effort event dissemination, with no additional control on QoS. Just a few implementations try to address some isolated QoS policy, making them not suitable for a SoS scenario. The contribution of this thesis is to devise a QoS layer that can be posed on top of a generic publish/subscribe middleware that enriches its service by addressing: (i) ordering, (ii) reliability and (iii) timeliness in event dissemination in SoS over WAN. Specifically, we first analyze several real case studies, by highlighting their QoS requirements in terms of ordering, reliability and timeliness, and compare these requirements with both current research prototypes and commercial systems. Then, we fill the gap by proposing novel algorithms to address those requirements. The proposed protocols can also be combined together in order to provide the QoS level required by the particular application. In this way, QoS issues do not need to be addressed at application level, so as to leave applications to implement just their native functionalities

A comparative evaluation of AMQP and MQTT protocols over unstable and mobile networks

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Message oriented middleware (MOM) refers to the software infrastructure supporting sending and receiving messages between distributed systems. AMQP and MQTT are the two most relevant protocols in this context. They are extensively used for exchanging messages since they provide an abstraction of the different participating system entities, alleviating their coordination and simplifying the communication programming details. These protocols, however, have not been thoroughly tested in the context of mobile or dynamic networks like vehicular networks. In this paper we present an experimental evaluation of both protocols in such scenarios, characterizing their behavior in terms of message loss, latency, jitter and saturation boundary values. Based on the results obtained, we provide criteria of applicability of these protocols, and we assess their performance and viability. This evaluation is of interest for the upcoming applications of MOM, especially to systems related to the Internet of Things.This work was partially supported by the Ministerio de Ciencia e Innovación, Spain, under Grant TIN2011-27543-C03-01.Luzuriaga Quichimbo, JE.; Pérez, M.; Boronat, P.; Cano Escribá, JC.; Tavares De Araujo Cesariny Calafate, CM.; Manzoni, P. (2015). A comparative evaluation of AMQP and MQTT protocols over unstable and mobile networks. IEEE. https://doi.org/10.1109/CCNC.2015.7158101

A platform for discovering and sharing confidential ballistic crime data.

Criminal investigations generate large volumes of complex data that detectives have to analyse and understand. This data tends to be "siloed" within individual jurisdictions and re-using it in other investigations can be difficult. Investigations into trans-national crimes are hampered by the problem of discovering relevant data held by agencies in other countries and of sharing those data. Gun-crimes are one major type of incident that showcases this: guns are easily moved across borders and used in multiple crimes but finding that a weapon was used elsewhere in Europe is difficult. In this paper we report on the Odyssey Project, an EU-funded initiative to mine, manipulate and share data about weapons and crimes. The project demonstrates the automatic combining of data from disparate repositories for cross-correlation and automated analysis. The data arrive from different cultural/domains with multiple reference models using real-time data feeds and historical databases

The Open Source DataTurbine Initiative: Streaming Data Middleware for Environmental Observing Systems

The Open Source DataTurbine Initiative is an international community of scientists and engineers sharing a common interest in real-time streaming data middleware and applications. The technology base of the OSDT Initiative is the DataTurbine open source middleware. Key applications of DataTurbine include coral reef monitoring, lake monitoring and limnology, biodiversity and animal tracking, structural health monitoring and earthquake engineering, airborne environmental monitoring, and environmental sustainability. DataTurbine software emerged as a commercial product in the 1990 s from collaborations between NASA and private industry. In October 2007, a grant from the USA National Science Foundation (NSF) Office of Cyberinfrastructure allowed us to transition DataTurbine from a proprietary software product into an open source software initiative. This paper describes the DataTurbine software and highlights key applications in environmental monitoring

Testing AMQP protocol on unstable and mobile networks

The final publication is available at Springer via http://dx.doi.org/ 10.1007/978-3-319-11692-1_22AMQP is a middleware protocol extensively used for exchanging messages in distributed applications. It provides an abstraction of the different participating parts and simplifies communication programming details. AMQP provides reliability features and alleviates the coordination of different entities of an application. However, implementations of this protocol have not been well tested in the context of mobile or unstable networks. This paper is the starting point of an experimental evaluation of AMQP protocol in such kind of scenarios. Our goal is to identify the limits of applicability of this middleware, assessing its the capacity in terms of message losses, latencies or jitter, when wireless devices are interrupted and reconnected. This evaluation is of interest for the upcoming applications in which personal devices and vehicles will collaborate, forming part of large complex systems.Luzuriaga Quichimbo, JE.; Pérez, M.; Boronat, P.; Cano Escribá, JC.; Tavares De Araujo Cesariny Calafate, CM.; Manzoni, P. (2014). Testing AMQP protocol on unstable and mobile networks. En Internet and Distributed Computing Systems. Springer. 250-260. doi:10.1007/978-3-319-11692-1_22S250260O’Hara, J.: Toward a Commodity Enterprise Middleware. Communications Magazine (2007)Gusmeroli, S., Piccione, S., Rotondi, D.: IoT@Work automation middleware system design and architecture. In: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA (2012)Foundation OpenStack. AMQP and Nova (2014)Corporation IMatix. Security and Robustness (2014)Subramoni, H., Marsh, G., Narravula, S., Lai, P., Panda, D.K.: Design and evaluation of benchmarks for financial applications using advanced message queuing protocol (AMQP) over infiniband. In: 2008 Workshop on High Performance Computational Finance, WHPCF 2008 (2008)Appel, S., Sachs, K., Buchmann, A.: Towards benchmarking of amqp. In: Proceedings of the Fourth ACM International Conference on Distributed Event-Based Systems, pp. 99–100. ACM (2010)Fernandes, J.L., Lopes, I.C., Rodrigues, J.J.P.C., Ullah, S.: Performance evaluation of RESTful web services and AMQP protocol. In: IEEE ICUFN, pp. 810–815 (2013)Lee, S., Kim, H., Hong, D.K., Ju, H.: Correlation analysis of MQTT loss and delay according to QoS level. In: International Conference on Information Networking, pp. 714–717 (2013)Inc. Pivotal Software. Messaging that just works (2014

A Review on Software Performance Analysis for Early Detection of Latent Faults in Design Models

Organizations and society could face major breakdown if IT strategies do not comply with performance requirements. This is more so in the era of globalization and emergence of technologies caused more issues. Software design models might have latent and potential issues that affect performance of software. Often performance is the neglected area in the industry. Identifying performance issues in the design phase can save time, money and effort. Software engineers need to know the performance requirements so as to ensure quality software to be developed. Software performance engineering a quantitative approach for building software systems that can meet performance requirements. There are many design models based on UML, Petri Nets and Product-Forms. These models can be used to derive performance models that make use of LQN, MSC, QNM and so on. The design models are to be mapped to performance models in order to predict performance of system early and render valuable feedback for improving quality of the system. Due to emerging distributed technologies such as EJB, CORBA, DCOM and SOA applications became very complex with collaboration with other software. The component based software systems, software systems that are embedded, distributed likely need more systematic performance models that can leverage the quality of such systems. Towards this end many techniques came into existence. This paper throws light into software performance analysis and its present state-of-the-art. It reviews different design models and performance models that provide valuable insights to make well informed decisions