@article {TAPAS2020324, title = {Experimenting with smart contracts for access control and delegation in IoT}, journal = {Future Generation Computer Systems}, volume = {111}, year = {2020}, pages = {324 - 338}, abstract = {In a Smart City scenario, the authors envisioned an IoT-Cloud framework for the management of boards and resources scattered over a geographic area. It can also become a tool to let device owners contribute freely to the infrastructure. In this paper, we present an authorization and delegation model for the IoT-Cloud based on blockchain technology. We focus on smart city{\^a}{\texteuro}TMs design and simulation of smart contracts to address the specific characteristics of smart environments and analyze access control and delegation mechanism in IoT. In particular, the scheme is implemented for the Ethereum platform in the form of smart contracts. We present the theoretical analysis of the proposed solution. We perform experiments on local testnet Ganache and public testnet Rinkeby to evaluate the performance of the presented models. Finally, we discuss the results and limitations of the system and possible solutions to issues.}, keywords = {Access control, authorization, Blockchain, Cloud, Delegation, Ethereum, IoT, smart cities, Smart contracts}, issn = {0167-739X}, doi = {https://doi.org/10.1016/j.future.2020.04.020}, url = {http://www.sciencedirect.com/science/article/pii/S0167739X18326979}, author = {Nachiket Tapas and Francesco Longo and Giovanni Merlino and Antonio Puliafito} } @article {Puliafito2019, title = {Fog computing for the Internet of Things: A survey}, journal = {ACM Transactions on Internet Technology - ACM}, volume = {19}, number = {2}, year = {2019}, note = {cited By 0}, publisher = {Association for Computing Machinery}, abstract = {

Research in the Internet of Things (IoT) conceives a world where everyday objects are connected to the Internet and exchange, store, process, and collect data from the surrounding environment. IoT devices are becoming essential for supporting the delivery of data to enable electronic services, but they are not sufficient in most cases to host application services directly due to their intrinsic resource constraints. Fog Computing (FC) can be a suitable paradigm to overcome these limitations, as it can coexist and cooperate with centralized Cloud systems and extends the latter toward the network edge. In this way, it is possible to distribute resources and services of computing, storage, and networking along the Cloud-to-Things continuum. Assuch, FC brings all the benefits of Cloud Computing (CC) closer to end (user) devices. This article presents a survey on the employment of FC to support IoT devices and services. The principles and literature characterizing FC are described, highlighting six IoT application domains that may benefit from the use of this paradigm. The extension of Cloud systems towards the network edge also creates new challenges and can have an impact on existing approaches employed in Cloud-based deployments. Research directions being adopted by the community are highlighted, with an indication of which of these are likely to have the greatest impact. An overview of existing FC software and hardware platforms for the IoT is also provided, along with the standardisation efforts in this area initiated by the OpenFog Consortium (OFC). {\textcopyright} 2019 Association for Computing Machinery.

}, keywords = {Application services, cloud computing, Digital storage, Electronic services, Fog, Fog computing, Internet of thing (IOT), Internet of Things, IOT applications, Resource Constraint, Software and hardwares, Surrounding environment, Surveys, Topological proximity}, issn = {15335399}, doi = {10.1145/3301443}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063939776\&doi=10.1145\%2f3301443\&partnerID=40\&md5=49ad63c8f0f1685fd1d7365914fc86f5}, author = {Carlo Puliafito and Enzo Mingozzi and Francesco Longo and Antonio Puliafito and Omer Rana} } @article {549, title = {An IoT service ecosystem for Smart Cities: The $\#$SmartME project}, journal = {Internet of Things - Elsevier}, volume = {5}, year = {2019}, pages = {12-33}, abstract = {

$\#$SmartME has been one of the first initiatives in Italy to realize a Smart City through the use of open technologies. Thanks to the use of low cost sensor-powered devices scattered over the city area, different {\textquotedblleft}smart{\textquotedblright} services have been deployed having the Stack4Things framework as the common underlying middleware.\ In this paper, we present the results obtained after 2 years of project highlighting the vertical solutions that have been proposed in different areas ranging from environmental monitoring to parking management.

}, keywords = {Arduino, Blockchain, cloud computing, IoT, OpenStack, Smart city}, issn = {2542-6605}, doi = {https://doi.org/10.1016/j.iot.2018.11.004}, author = {Dario Bruneo and Salvatore Distefano and Maurizio Giacobbe and Antonino Longo Minnolo and Francesco Longo and Giovanni Merlino and Davide Mulfari and Alfonso Panarello and Giuseppe Patan{\`e} and Antonio Puliafito and Carlo Puliafito and Nachiket Tapas} } @article {Panarello2018, title = {Blockchain and iot integration: A systematic survey}, journal = {Sensors - MDPI}, volume = {18}, number = {8}, year = {2018}, note = {cited By 10}, publisher = {MDPI AG}, abstract = {

The Internet of Things (IoT) refers to the interconnection of smart devices to collect data and make intelligent decisions. However, a lack of intrinsic security measures makes IoT vulnerable to privacy and security threats. With its {\textquotedblleft}security by design,{\textquotedblright} Blockchain (BC) can help in addressing major security requirements in IoT. BC capabilities like immutability, transparency, auditability, data encryption and operational resilience can help solve most architectural shortcomings of IoT. This article presents a comprehensive survey on BC and IoT integration. The objective of this paper is to analyze the current research trends on the usage of BC-related approaches and technologies in an IoT context. This paper presents the following novelties, with respect to related work: (i) it covers different application domains, organizing the available literature according to this categorization, (ii) it introduces two usage patterns, i.e., device manipulation and data management (open marketplace solution), and (iii) it reports on the development level of some of the presented solutions. We also analyze the main challenges faced by the research community in the smooth integration of BC and IoT, and point out the main open issues and future research directions. Last but not least, we also present a survey about novel uses of BC in the machine economy. {\textcopyright} 2018 by the authors. Licensee MDPI, Basel, Switzerland.

}, keywords = {Blockchain, Cryptography, Future research directions, Information management, Integration, Intelligent decisions, Internet of thing (IOT), Internet of Things, Privacy and security, Research communities, Security by designs, Security measure, Security requirements, Surveying, Surveys}, issn = {14248220}, doi = {10.3390/s18082575}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051401073\&doi=10.3390\%2fs18082575\&partnerID=40\&md5=07247598c49b9507bea67e04bb3e325f}, author = {Alfonso Panarello and Nachiket Tapas and Giovanni Merlino and Francesco Longo and Antonio Puliafito} } @proceedings {Tapas2018411, title = {Blockchain-Based IoT-cloud authorization and delegation}, journal = {Proceedings - 2018 IEEE International Conference on Smart Computing, SMARTCOMP 2018}, year = {2018}, note = {cited By 0; Conference of 4th IEEE International Conference on Smart Computing, SMARTCOMP 2018 ; Conference Date: 18 June 2018 Through 20 June 2018; Conference Code:138285}, pages = {411-416}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Taormina, Italy - 18-20 June 2018}, abstract = {

In a Smart City scenario, the authors envisioned an IoT-Cloud framework for the management of boards and resources scattered over a geographic area. It can also become a tool to let device owners contribute freely to the infrastructure. In comparison to datacenter-oriented Cloud middleware, the administrator and the owner of the infrastructure are not one and the same. This translates into the requirement to support delegation-enabled authorization. In this paper, the authors investigate an authorization and delegation model for the IoT-Cloud based on blockchain technology. In particular, the scheme is implemented in the form of smart contracts over the Ethereum platform. Indeed, this approach represents an enhancement, over a function previously designed in a centralized fashion, by enabling the user to audit authorization operations and inspect how access control is actually performed, without blindly trusting the Cloud as a proxy for access to resources. {\textcopyright} 2018 IEEE.

}, keywords = {Access control, Access to resources, authorization, Blockchain, Cloud middlewares, Clouds, Delegation, Delegation modeling, Ethereum, Geographic areas, Internet of Things, middleware, Smart city, Smart contracts}, isbn = {9781538647059}, doi = {10.1109/SMARTCOMP.2018.00038}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051495365\&doi=10.1109\%2fSMARTCOMP.2018.00038\&partnerID=40\&md5=57e82ce12e19c3286c34b0612a587237}, author = {Nachiket Tapas and Giovanni Merlino and Francesco Longo} } @proceedings {535, title = {Building a Smart City Service Platform in Messina with the $\#$SmartME Project}, journal = {The 32nd IEEE International Conference on Advanced Information Networking and Applications (IEEE AINA-2018)}, year = {2018}, month = {05/2018}, address = {Pedagogical University of Cracow, Poland}, abstract = {

Some words mark an era, and "Smart City" is definitely one of these. A Smart City is an urban area where the Information and Communication Technologies (ICT) are employed to improve citizens{\textquoteright} Quality of Life (QoL) in areas such as: mobility, urban surveillance, and energy management. Throughout this paper, we present the $\#$SmartME project, which aims to create an infrastructure and an ecosystem of "smart" services by exploiting existing devices, sensors, and actuators distributed in the city of Messina. We also present the Stack4Things framework, which is the management core of the $\#$SmartME project.

}, keywords = {$\#$SmartME, Arduino, Blockchain, cloud computing, IoT, OpenData, OpenStack, Smart city, Stack4Things}, author = {Dario Bruneo and Sebastiano Chillari and Salvatore Distefano and Maurizio Giacobbe and Antonino Longo Minnolo and Francesco Longo and Giovanni Merlino and Davide Mulfari and Alfonso Panarello and Giuseppe Patan{\`e} and Antonio Puliafito and Carlo Puliafito and Marco Scarpa and Nachiket Tapas and Giancarlo Visalli} } @proceedings {Puliafito201897, title = {Companion fog computing: supporting things mobility through container migration at the edge}, journal = {Proceedings - 2018 IEEE International Conference on Smart Computing, SMARTCOMP 2018}, year = {2018}, note = {cited By 0; Conference of 4th IEEE International Conference on Smart Computing, SMARTCOMP 2018 ; Conference Date: 18 June 2018 Through 20 June 2018; Conference Code:138285}, pages = {97-105}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Taormina, Italy - 18-20 June 2018}, abstract = {

Due to their intrinsic resource constraints, the mobile Internet of Things (IoT) devices are not able to provide intensive services by just relying on their own facilities. Fog Computing effectively helps overcome this hurdle. Indeed, it extends the Cloud toward the network edge, distributing resources and services of computing, storage, and networking close to the end devices. This topological proximity is the key enabler of several advantages that are essential in many emerging ICT domains. Nonetheless, the mobility of an IoT device compromises such benefits as it increases the topological distance to the serving Fog node. Therefore, the Fog service has to be migrated in order to be always close enough to the served IoT device. We name this Companion Fog Computing (CFC), since the Fog service behaves as a {\textquoteright}companion{\textquoteright} of the correspondent application on the mobile device. In this paper, we present a Fog Computing Platform that performs stateful container (i.e., Fog service) migrations in order to enable CFC. Specifically, we introduce a CFC model from which we derive a reference architecture comprising all the functionalities required in a platform to make migration decisions and carry them out. Moreover, we demonstrate the soundness of the proposed reference architecture by discussing a proof-of-concept implementation based on the Stack4Things (S4T) platform, and we report a set of conducted experiments to show the feasibility of stateful container migrations. {\textcopyright} 2018 IEEE.

}, keywords = {Carrier mobility, Computing platform, containers, Docker, Fog, Fog computing, Internet of Things, Migration, Mobile devices, Network architecture, Proof of concept, Reference architecture, Resource Constraint, Topological distance, Topological proximity, Topology}, isbn = {9781538647059}, doi = {10.1109/SMARTCOMP.2018.00079}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051489867\&doi=10.1109\%2fSMARTCOMP.2018.00079\&partnerID=40\&md5=4a8069123a5f19d5e842a86b2e9163f4}, author = {Carlo Puliafito and Enzo Mingozzi and Carlo Vallati and Francesco Longo and Giovanni Merlino} } @article {Dautov201829822, title = {Data Processing in Cyber-Physical-Social Systems Through Edge Computing}, journal = {IEEE Access - IEEE}, volume = {6}, year = {2018}, note = {cited By 0}, pages = {29822-29835}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, abstract = {

Cloud and Fog computing have established a convenient and widely adopted approach for computation offloading, where raw data generated by edge devices in the Internet of Things (IoT) context is collected and processed remotely. This vertical offloading pattern, however, typically does not take into account increasingly pressing time constraints of the emerging IoT scenarios, in which numerous data sources, including human agents (i.e., Social IoT), continuously generate large amounts of data to be processed in a timely manner. Big data solutions could be applied in this respect, provided that networking issues and limitations related to connectivity of edge devices are properly addressed. Although edge devices are traditionally considered to be resource-constrained, main limitations refer to energy, networking, and memory capacities, whereas their ever-growing processing capabilities are already sufficient to be effectively involved in actual (big data) processing. In this context, the role of human agents is no longer limited to passive data generation, but can also include their voluntary involvement in relatively complex computations. This way, users can share their personal computational resources (i.e., mobile phones) to support collaborative data processing, thereby turning the existing IoT into a global cyber-physical-social system (CPSS). To this extent, this paper proposes a novel IoT/CPSS data processing pattern based on the stream processing technology, aiming to distribute the workload among a cluster of edge devices, involving mobile nodes shared by contributors on a voluntary basis, and paving the way for cluster computing at the edge. Experiments on an intelligent surveillance system deployed on an edge device cluster demonstrate the feasibility of the proposed approach, illustrating how its distributed in-memory data processing architecture can be effective. {\textcopyright} 2013 IEEE.

}, keywords = {Apache NiFi, Big Data, Cameras, Cellular telephone systems, cloud computing, Cluster computing, Computer architecture, Cyber physical social systems, Cyber Physical System, Edge computing, Fog computing, Horizontal and Vertical Offloading, Internet of Things, Media streaming, Network security, Servers, Stream processing, Streaming media}, issn = {21693536}, doi = {10.1109/ACCESS.2018.2839915}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047619039\&doi=10.1109\%2fACCESS.2018.2839915\&partnerID=40\&md5=48b52a73084c2f6396c4ce1dd6a690f4}, author = {Rustem Dautov and Salvatore Distefano and Dario Bruneo and Francesco Longo and Giovanni Merlino and Antonio Puliafito} } @article {Bruneo2018267, title = {Integrating IoT and cloud in a smart city context: The $\#$SmartME case study}, journal = {International Journal of Computer Applications in Technology - Inderscience Enterprises Ltd.}, volume = {57}, number = {4}, year = {2018}, note = {cited By 0}, pages = {267-280}, publisher = {Inderscience Enterprises Ltd.}, abstract = {

$\#$SmartME is a crowdfounding project that aims at exploring the possible synergies between the cloud computing and the Internet of Things paradigms. The project{\textquoteright}s main aim is to morph Messina into a smart city. In this direction, the Stack4Things framework has been implemented, extending OpenStack towards the management of Internet of Things resources. This paper summarises the first two years of the $\#$SmartME project and presents technical details about Stack4Things with specific reference to the underlying technologies and to the web portals that are used for administration and semantically-enabled data retrieval. Copyright {\textcopyright} 2018 Inderscience Enterprises Ltd.

}, keywords = {Data retrieval, Iaas clouds, Internet of Things, Learning systems, OpenStack, Portals, Semantic Web, Smart city, Technical details}, issn = {09528091}, doi = {10.1504/IJCAT.2018.093528}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050816820\&doi=10.1504\%2fIJCAT.2018.093528\&partnerID=40\&md5=2a625990009cbd28073e018e196de63f}, author = {Dario Bruneo and Francesco Longo and Giovanni Merlino and Antonio Puliafito and Nidhi Kushwaha} } @article {Bruneo201857, title = {I/Ocloud: Adding an IoT dimension to cloud infrastructures}, journal = {Computer}, volume = {51}, number = {1}, year = {2018}, note = {cited By 0}, pages = {57-65}, publisher = {IEEE Computer Society}, issn = {00189162}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042913312\&partnerID=40\&md5=237eb8a281bcad75b510b4802802d1ec}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Giovanni Merlino and Antonio Puliafito} } @article {Dautov20181475, title = {Metropolitan intelligent surveillance systems for urban areas by harnessing IoT and edge computing paradigms}, journal = {Software - Practice and Experience - John Wiley \& Sons, Ltd.}, volume = {48}, number = {8}, year = {2018}, note = {cited By 0}, pages = {1475-1492}, publisher = {John Wiley and Sons Ltd}, abstract = {

Recent technological advances led to the rapid and uncontrolled proliferation of intelligent surveillance systems (ISSs), serving to supervise urban areas. Driven by pressing public safety and security requirements, modern cities are being transformed into tangled cyber-physical environments, consisting of numerous heterogeneous ISSs under different administrative domains with low or no capabilities for reuse and interaction. This isolated pattern renders itself unsustainable in city-wide scenarios that typically require to aggregate, manage, and process multiple video streams continuously generated by distributed ISS sources. A coordinated approach is therefore required to enable an interoperable ISS for metropolitan areas, facilitating technological sustainability to prevent network bandwidth saturation. To meet these requirements, this paper combines several approaches and technologies, namely the Internet of Things, cloud computing, edge computing and big data, into a common framework to enable a unified approach to implementing an ISS at an urban scale, thus paving the way for the metropolitan intelligent surveillance system (MISS). The proposed solution aims to push data management and processing tasks as close to data sources as possible, thus increasing performance and security levels that are usually critical to surveillance systems. To demonstrate the feasibility and the effectiveness of this approach, the paper presents a case study based on a distributed ISS scenario in a crowded urban area, implemented on clustered edge devices that are able to off-load tasks in a {\textquotedblleft}horizontal{\textquotedblright} manner in the context of the developed MISS framework. As demonstrated by the initial experiments, the MISS prototype is able to obtain face recognition results 8 times faster compared with the traditional off-loading pattern, where processing tasks are pushed {\textquotedblleft}vertically{\textquotedblright} to the cloud. Copyright {\textcopyright} 2018 John Wiley \& Sons, Ltd.

}, keywords = {Big Data, cloud computing, Distributed Smart Cameras, Edge computing, Face recognition, Information management, Intelligent surveillance systems, Internet of Things, monitoring, Multiple video streams, Network security, Public safety and securities, Security systems, Smart city, Stack4Things, Stream processing, Surveillance systems, Technological advances}, issn = {00380644}, doi = {10.1002/spe.2586}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049578094\&doi=10.1002\%2fspe.2586\&partnerID=40\&md5=25de910451975bb24c9cfbdf6ca69066}, author = {Rustem Dautov and Salvatore Distefano and Dario Bruneo and Francesco Longo and Giovanni Merlino and Antonio Puliafito and Rajkumar Buyya} } @proceedings {Maisano2018, title = {Reducing Complexity of 3D Indoor Object Detection}, journal = {IEEE 4th International Forum on Research and Technologies for Society and Industry, RTSI 2018 - Proceedings}, year = {2018}, note = {cited By 0; Conference of 4th IEEE International Forum on Research and Technologies for Society and Industry, RTSI 2018 ; Conference Date: 10 September 2018 Through 13 September 2018; Conference Code:143080}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Palermo, Italy - 10-13 September 2018}, abstract = {

This work deals with the problem of amodal perception of 3D object detection in indoor environments. We revisited a novel method of 3D object detection [4], in terms of complexity and runtime speed. 3D detection regards not only objects localization in the 3D world, but also estimating their physical sizes and poses, even if only parts of them are visible in the RGB-D image. By following the 2.5D representation approach, the system under study achieves a better mean average precision in detection (40.1\%) with respect to all recent methods, but the complexity of the system is very high and, at the moment, its implementation doesn{\textquoteright}t fit in a small device with low resources in memory and computation. We revisited the referenced system through a variation in its network architecture by introducing a well-adapted and {\textquoteright}fine-tuned{\textquoteright} MobileNet from Google, with the goal of reducing the complexity of the whole system. Considerable reduction in complexity, computational cost (MAC operations) and memory requirements have been achieved. Many detected classes showed an acceptable level of accuracy and also the speed of the recognition system increased. Final experiments have been conducted on NYUV2 dataset. {\textcopyright} 2018 IEEE.

}, keywords = {3-D object detections, Complex networks, Complexity reduction, Computational costs, Embedded device, Indoor environment, Memory requirements, MobileNet, Network architecture, Object detection, Object recognition, Recognition systems}, isbn = {9781538662823}, doi = {10.1109/RTSI.2018.8548514}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85060018242\&doi=10.1109\%2fRTSI.2018.8548514\&partnerID=40\&md5=e5013d2f13df31fcdea840d7f8859acf}, author = {Roberta Maisano and Valeria Tomaselli and Alessandro Capra and Francesco Longo and Antonio Puliafito} } @proceedings {Puliafito2018368, title = {Virtualization and migration at the network edge: An overview}, journal = {Proceedings - 2018 IEEE International Conference on Smart Computing, SMARTCOMP 2018}, year = {2018}, note = {cited By 1; Conference of 4th IEEE International Conference on Smart Computing, SMARTCOMP 2018 ; Conference Date: 18 June 2018 Through 20 June 2018; Conference Code:138285}, pages = {368-374}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Taormina, Italy - 18-20 June 2018}, abstract = {

As for the Cloud, essential features of Fog Computing are both virtualization and the capability to migrate virtual environments among nodes. In this paper, we thoroughly report both the state-of-The-Art virtualization and migration techniques and their available implementations. In particular, we investigate the aptness of such technologies for a specific layer of the Fog hierarchy, namely the network edge. Indeed, this layer presents some characteristics that distinguish it from the Cloud so that a virtualization or migration technique that represents a good compromise for the Cloud might not be likewise suitable for the edge. {\textcopyright} 2018 IEEE.

}, keywords = {containers, Essential features, Fog, Fog computing, Migration, Migration technique, Network edges, Smart city, State of the art, Virtual Machine, Virtual reality, Virtualization}, isbn = {9781538647059}, doi = {10.1109/SMARTCOMP.2018.00031}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051498294\&doi=10.1109\%2fSMARTCOMP.2018.00031\&partnerID=40\&md5=7f2642da7694ddacd86212b216c00ec2}, author = {Carlo Puliafito and Enzo Mingozzi and Carlo Vallati and Francesco Longo and Giovanni Merlino} } @article {Longo201737, title = {An approach for resiliency quantification of large scale systems}, journal = {Performance Evaluation Review}, volume = {44}, number = {4}, year = {2017}, note = {cited By 0}, pages = {37-48}, publisher = {Association for Computing Machinery}, abstract = {

We quantify the resiliency of large scale systems upon changes encountered beyond the normal system behavior. Formal definitions for resiliency and change are provided together with general steps for resiliency quantification and a set of resiliency metrics that can be used to quantify the effects of changes. A formalization of the approach is also shown in the form of a set of four algorithms that can be applied when large scale systems are modeled through stochastic analytic state space models (monolithic models or interacting sub-models). In particular, in the case of interacting submodels, since resiliency quantification involves understanding the transient behavior of the system, fixed-point variables evolve with time leading to non-homogenous Markov chains. At the best of our knowledge, this is the first paper facing this problem in a general way. The proposed approach is applied to an Infrastructure-As-A-Service (IaaS) Cloud use case. Specifically, we assess the impact of changes in demand and available capacity on the Cloud resiliency and we show that the approach proposed in this paper can scale for a real sized Cloud without significantly compromising the accuracy.

}, keywords = {Available capacity, Chains, Formal definition, Homogenous Markov chain, Infrastructure as a service (IaaS), Large scale systems, Markov processes, Non-homogeneous, Resiliency quantification, State - space models, State space methods, Stochastic models, Stochastic systems, Submodels, Transient behavior}, issn = {01635999}, doi = {10.1145/3092819.3092825}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019853222\&doi=10.1145\%2f3092819.3092825\&partnerID=40\&md5=6266fffb7aad937fefad706e31fcd7da}, author = {Francesco Longo and Rahul Ghosh and Vijay K. Naik and A.J. Rindos and Kishor Trivedi} } @proceedings {KiranBhattacharjee2017, title = {Extending Bluetooth Low Energy PANs to Smart City Scenarios}, journal = {2017 IEEE International Conference on Smart Computing, SMARTCOMP 2017}, year = {2017}, note = {cited By 0; Conference of 2017 IEEE International Conference on Smart Computing, SMARTCOMP 2017 ; Conference Date: 29 May 2017 Through 31 May 2017; Conference Code:128356}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Hong Kong; China; 29-31 May 2017}, abstract = {

Smart Cities are the perfect ecosystem where IoT technology could be applied. In particular, to allow a direct interaction with objets scattered over a city (e.g, parking slots, light posts, gates) a powerful and scalable architecture has to be envisioned. In this paper, using Bluetooth Low Energy as underlying technology, we extend the concept of Personal Area Networks to include smart city objects so that a user can easily interact with them in a geolocalized and real time manner. A prototype implementing a smart gate has been developed in our University Campus in order to demonstrate the feasibility of the proposed approach. {\textcopyright} 2017 IEEE.

}, isbn = {9781509065172}, doi = {10.1109/SMARTCOMP.2017.7947007}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85022325311\&doi=10.1109\%2fSMARTCOMP.2017.7947007\&partnerID=40\&md5=f7dec9a77a6e51625d129bc22d29369a}, author = {Kiran Bhattacharjee, A. and Dario Bruneo and Salvatore Distefano and Francesco Longo and Giovanni Merlino and Antonio Puliafito} } @proceedings {Bruneo2017, title = {Head in a Cloud: An approach for Arduino YUN virtualization}, journal = {GIoTS 2017 - Global Internet of Things Summit, Proceedings}, year = {2017}, note = {cited By 0; Conference of 2017 Global Internet of Things Summit, GIoTS 2017 ; Conference Date: 6 June 2017 Through 9 June 2017; Conference Code:130055}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Geneva; Switzerland; 6-9 June 2017}, abstract = {

Smart boards are triggering the IoT revolution, allowing to make common objects and things smart through their network, storage and processing capabilities. Arduino boards have a prominent role in this revolution, due to their customizability and programming freedom. From a different perspective, another strategic development for the IoT is towards Cloud, allowing to properly manage things and data ubiquitously, on demand, as services. Pushing in this direction, we can pave the way to the Cloud of Things, where real things, rather than the data they produce, can be provided to third parties, by adopting a {\textquoteright}device-centric{\textquoteright} approach. To this purpose, virtualization of physical resources becomes an essential step and core mechanism. In this paper we focus on smart board virtualization, implementing a flexible solution for Arduino boards based on Stack4Things, allowing to create, multiplex, migrate and deploy virtual boards in IoT-Cloud contexts. The results obtained by a preliminary implementation and experiments on the $\#$SmartME testbed are shown in the paper to demonstrate the feasibility and the effectiveness of the proposed solution. {\textcopyright} 2017 IEEE.

}, keywords = {Arduino YUN, Clouds, Computer operating systems, Core mechanisms, Customizability, Digital storage, GPIO pins, Internet of Things, Physical resources, Processing capability, Stack4Things, Strategic development, Virtual reality, Virtualization}, isbn = {9781509058730}, doi = {10.1109/GIOTS.2017.8016263}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029291785\&doi=10.1109\%2fGIOTS.2017.8016263\&partnerID=40\&md5=4a8eed3e1348ab91166e648151d625c0}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Giovanni Merlino and Antonio Puliafito and Angelo Zaia} } @article {Distefano2017382, title = {Hospitalized Patient Monitoring and Early Treatment Using IoT and Cloud}, journal = {BioNanoScience}, volume = {7}, number = {2}, year = {2017}, note = {cited By 0}, pages = {382-385}, publisher = {Springer New York LLC}, abstract = {

The adoption of Internet of Things devices and, more in general, embedded systems, endowed with sensors and actuators, keeps rising globally, and the scope of their involvement broadens, for instance in e-Health applications. This work describes our integration of IoT paradigms and resource ecosystems with a tailored Cloud-oriented device-centric environment, by focusing on an e-Health scenario, featuring monitoring and early treatment of hospitalized patients, by focusing on Cloud-enabled event detection coupled with coordinated reaction. {\textcopyright} 2016, Springer Science+Business Media New York.

}, keywords = {Clouds, Coordinated reactions, Coordination reactions, E health, e-Health applications, Early treatment, embedded systems, Event detection, Health, Internet of Things, OpenStack, Patient monitoring, Patient treatment, sensors and actuators}, issn = {21911630}, doi = {10.1007/s12668-016-0335-5}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019076002\&doi=10.1007\%2fs12668-016-0335-5\&partnerID=40\&md5=cd98d3d0b82a5392d0f5191656dee389}, author = {Salvatore Distefano and Dario Bruneo and Francesco Longo and Giovanni Merlino and Antonio Puliafito} } @article {Distefano201722, title = {Marking dependency in non-Markovian stochastic Petri nets}, journal = {Performance Evaluation}, volume = {110}, year = {2017}, note = {cited By 0}, pages = {22-47}, publisher = {Elsevier B.V.}, abstract = {

Marking dependency is a powerful tool that allows different firing time distributions to be associated with a stochastic Petri net transition, depending on the marking. Through this feature, the modeler can easily and compactly represent advanced properties and behaviors of the system. While a semantics and specific solution techniques have been provided for generalized stochastic Petri nets thus covering homogeneous Markovian aspects, in the non-homogeneous/non-Markovian case marking dependency still needs to be investigated. To fill this gap, this paper provides a formalization of marking dependent semantics in non-Markovian stochastic Petri nets (NMSPNs) and a solution technique, based on phase type distributions and Kronecker algebra, able to deal with such a feature allowing both transient and steady-state analyses. To motivate the actual need of marking dependency in NMSPN modeling and to demonstrate the potential of such a feature as well as the validity of the proposed solution technique a case study on a multi-core CPU system with power management facilities is explored. {\textcopyright} 2017 Elsevier B.V.

}, keywords = {Algebra, energy management, Kronecker algebra, Marking dependency, Multi-core cpus, non-Markovian stochastic Petri nets, Petri nets, phase type distributions, Power management, Program processors, Random access storage, Semantics, Stochastic systems}, issn = {01665316}, doi = {10.1016/j.peva.2017.03.001}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85016027299\&doi=10.1016\%2fj.peva.2017.03.001\&partnerID=40\&md5=a00a4d3147bd499b5f8879d3573b4670}, author = {Salvatore Distefano and Francesco Longo and Marco Scarpa} } @proceedings {Tricomi2017, title = {Orchestrated Multi-Cloud Application Deployment in OpenStack with TOSCA}, journal = {2017 IEEE International Conference on Smart Computing, SMARTCOMP 2017}, year = {2017}, note = {cited By 0; Conference of 2017 IEEE International Conference on Smart Computing, SMARTCOMP 2017 ; Conference Date: 29 May 2017 Through 31 May 2017; Conference Code:128356}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Hong Kong; China; 29-31 May 2017}, abstract = {

Cloud computing is becoming a relatively mature paradigm in the ICT landscape. In light of the growing appetite for resources and service levels on par with user expectations, multi-cloud scenarios are becoming the next frontier in the usage of distributed datacenters for private and hybrid Cloud scenarios. Application deployment in particular is a noteworthy feature to be evaluated as microservices become mainstream in adoption. Especially so when considered jointly with orchestration services; indeed OpenStack, as the most widely adopted Cloud middleware among the OpenSource community, features an orchestration subsystem, and may orchestrate the deployment of applications and services. In this work the authors will describe an architecture, developed within the H2020 BEACON project, for a standardized approach to orchestrated application deployment in multi-Cloud OpenStack-based setups, with TOSCA providing the specifications. {\textcopyright} 2017 IEEE.

}, keywords = {Cloud federations, deployment, microservices, middleware, Multi-clouds, OpenStack, orchestration, Platform as a Service (PaaS), TOSCA}, isbn = {9781509065172}, doi = {10.1109/SMARTCOMP.2017.7947027}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85023168002\&doi=10.1109\%2fSMARTCOMP.2017.7947027\&partnerID=40\&md5=94bbf6ca2fa1b1d2b92047683723948c}, author = {Giuseppe Tricomi and Alfonso Panarello and Giovanni Merlino and Francesco Longo and Dario Bruneo and Antonio Puliafito} } @article {Distefano2017439, title = {Personalized Health Tracking with Edge Computing Technologies}, journal = {BioNanoScience}, volume = {7}, number = {2}, year = {2017}, note = {cited By 0}, pages = {439-441}, publisher = {Springer New York LLC}, abstract = {

The health monitoring component is the essential block, a pillar of several e-health systems. Plenty of health tracking applications and specific technologies such as smart devices, wearables, and data management systems are available. To be effective, promptly reacting to issues, a health monitoring service must ensure short delays in data sensing, collection, and processing activities. This is an open problem that distributed computing paradigms, such as Internet of Things (IoT), Cloud, and Edge computing, could address. The solution proposed in this paper is based on Stack4Things, an IoT-Cloud framework to manage edge nodes such as mobiles, smart objects, network devices, workstations, as a whole, a computing infrastructure allowing to provide resources on-demand, as services, to end users. Through Stack4Things facilities, the health tracking system can locate the closer computing resource to offload processing and thus reducing latency per the Edge computing paradigm. {\textcopyright} 2016, Springer Science+Business Media New York.

}, keywords = {Clouds, Computing infrastructures, Data management system, Distributed computer systems, Edge computing, Health, Health monitoring, Health tracking systems, human, human computer interaction, Information management, Internet, Internet of Things, Internet of Things (IOT), monitoring, Stack4Things, Tracking application, Wearable technology}, issn = {21911630}, doi = {10.1007/s12668-016-0388-5}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019121810\&doi=10.1007\%2fs12668-016-0388-5\&partnerID=40\&md5=e5aa843f2f869945fe04d5f62c97a6c5}, author = {Salvatore Distefano and Dario Bruneo and Francesco Longo and Giovanni Merlino and Antonio Puliafito} } @proceedings {Kushwaha2018864, title = {Providing sensor services by data correlation: The $\#$SmartME approach}, journal = {Conference on Complex, Intelligent, and Software Intensive Systems}, volume = {611}, year = {2017}, note = {cited By 0; Conference of 11th International Conference on Complex, Intelligent, and Software Intensive Systems, CISIS 2017 ; Conference Date: 10 July 2017 Through 12 July 2017}, pages = {864-874}, publisher = {Springer Verlag}, address = {Torino, Italy - 10-12 July 2017}, abstract = {

In the current era Internet is the most used medium for sharing and retrieving the information for building applications which are commonly developed for enhancing the user experience in terms of comfort, communication. For this, the need of real-time sensor data gains importance. The data collected from the physical objects should be easily available for different applications. Semantic representation of the sensor data directly addresses the problem of storing it in logical, easily accessible and extensible manner. Our paper works towards converting the already collected sensor data of the $\#$SmartME project into semantic format and also proposes real-time storage of semantically enriched sensor data. To build applications using these sensor data the authors consider mainly three kinds of sensors, i.e., Temperature, Humidity, Pressure. Predicting the observed value of any sensor data is the main aim of this work. The analysis leverages other sensors \& environmental parameters such as Date, Time, Longitude, Latitude, Altitude etc. Correlation among these parameters and the accuracy of the predicted results showed the suitability of our proposed idea. {\textcopyright} Springer International Publishing AG 2018.

}, keywords = {Building applications, Complex networks, Correlations, Data correlations, Data mining, Digital storage, Environmental parameter, Real time sensors, Semantic representation, Semantic Web, sensor networks, SmartME, Stack4Things}, isbn = {9783319615653}, issn = {21945357}, doi = {10.1007/978-3-319-61566-0_82}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026317817\&doi=10.1007\%2f978-3-319-61566-0_82\&partnerID=40\&md5=7b4cb65c4b09ea03df77bbea893f4002}, author = {Nidhi Kushwaha and Giovanni Merlino and Francesco Longo and Dario Bruneo and Antonio Puliafito and O.P. Vyas} } @proceedings {Dautov2018792, title = {Pushing intelligence to the edge with a stream processing architecture}, journal = {Proceedings - 2017 IEEE International Conference on Internet of Things, IEEE Green Computing and Communications, IEEE Cyber, Physical and Social Computing, IEEE Smart Data, iThings-GreenCom-CPSCom-SmartData 2017}, year = {2017}, note = {cited By 3; Conference of Joint 10th IEEE International Conference on Internet of Things, iThings 2017, 13th IEEE International Conference on Green Computing and Communications, GreenCom 2017, 10th IEEE International Conference on Cyber, Physical and Social Computing, CPSCom 2017 and the 3rd IEEE International Conference on Smart Data, Smart Data 2017 ; Conference Date: 21 June 2017 Through 23 June 2017; Conference Code:134517}, pages = {792-799}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Exeter, UK - 21-23 June 2017}, abstract = {

The cloud computing paradigm underpins the Internet of Things (IoT) by offering a seemingly infinite pool of resources for processing/storing extreme amounts of data generated by complex IoT systems. The cloud has established a convenient and widely adopted approach, where raw data are vertically offloaded to cloud servers from resource-constrained edge devices, which are only seen as simple data generators, not capable of performing more sophisticated processing activities. However, there are more and more emerging scenarios, where the amount of data to be transferred over the network to the cloud is associated with increased network latency, making the results of the computation obsolete. As various categories of edge devices are becoming more and more powerful in terms of hardware resources - specifically, CPU and memory - the established way of off-loading computation to the cloud is not always seen as the most convenient approach. Accordingly, this paper presents a Stream Processing architecture for spreading workload among a local cluster of edge devices to process data in parallel, thus achieving faster execution and response times. The experimental results suggest that such a distributed in-memory approach to data processing at the very edge of a computational network has a potential to address a wide range of IoT-related scenarios. {\textcopyright} 2017 IEEE.

}, keywords = {Apache NiFi, cloud computing, Cluster computing, Computational networks, Data handling, Edge computing, Green Computing, Hardware resources, Horizontal offloading, Internet of thing (IOT), Internet of Things, Memory architecture, Network architecture, Network latencies, Processing activity, Stream processing}, isbn = {9781538630655}, doi = {10.1109/iThings-GreenCom-CPSCom-SmartData.2017.121}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047094836\&doi=10.1109\%2fiThings-GreenCom-CPSCom-SmartData.2017.121\&partnerID=40\&md5=4e5a4b0eaffa179565af183066520cdf}, author = {Rustem Dautov and Salvatore Distefano and Dario Bruneo and Francesco Longo and Giovanni Merlino and Antonio Puliafito} } @article {Longo201753, title = {Stack4Things: a sensing-and-actuation-as-a-service framework for IoT and cloud integration}, journal = {Annales des Telecommunications/Annals of Telecommunications - Institut Mines-T{\'e}l{\'e}com and Springer-Verlag France}, volume = {72}, number = {1-2}, year = {2017}, note = {cited By 0}, pages = {53-70}, publisher = {Springer-Verlag France}, abstract = {

With the increasing adoption of embedded smart devices and their involvement in different application fields, complexity may quickly grow, thus making vertical ad hoc solutions ineffective. Recently, the Internet of Things (IoT) and Cloud integration seems to be one of the winning solutions in order to opportunely manage the proliferation of both data and devices. In this paper, following the idea to reuse as much tooling as possible, we propose, with regards to infrastructure management, to adopt a widely used and competitive framework for Infrastructure-as-a-Service such as OpenStack. Therefore, we describe approaches and architectures so far preliminary implemented for enabling Cloud-mediated interactions with droves of sensor- and actuator-hosting nodes by presenting Stack4Things, a framework for Sensing-and-Actuation-as-a-Service (SAaaS). In particular, starting from a detailed requirement analysis, in this work, we focus on the subsystems of Stack4Things devoted to resource control and management as well as on those related to the management and collection of sensing data. Several use cases are presented justifying how our proposed framework can be viewed as a concrete step toward the complete fulfillment of the SAaaS vision. {\textcopyright} 2016, Institut Mines-T{\'e}l{\'e}com and Springer-Verlag France.

}, keywords = {Clouds, Information management, Infrastructure as a service (IaaS), Infrastructure managements, Internet of thing (IOT), Internet of Things, Mediated interaction, OpenStack, Requirement analysis, SAaaS, WAMP, WebSocket}, issn = {00034347}, doi = {10.1007/s12243-016-0528-5}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84976292948\&doi=10.1007\%2fs12243-016-0528-5\&partnerID=40\&md5=f334f652432ae0993795644204689e9c}, author = {Francesco Longo and Dario Bruneo and Salvatore Distefano and Giovanni Merlino and Antonio Puliafito} } @proceedings {Dautov2017, title = {Towards a global intelligent surveillance system}, journal = {11th International Conference on Distributed Smart Cameras, ICDSC 2017}, year = {2017}, note = {cited By 2; Conference of 11th International Conference on Distributed Smart Cameras, ICDSC 2017 ; Conference Date: 5 September 2017 Through 7 September 2017; Conference Code:132201}, publisher = {Association for Computing Machinery}, address = {Stanford, USA - 05-07 September 2017}, abstract = {

Recent technological advances have led to the rapid development of Intelligent Surveillance Systems (ISSs), ubiquitously present in modern urban spaces are constantly generating streams of raw data. As most of the actual Internet traffic is nowadays constituted by visual data streams, often originated by ISSs, it is important to properly manage these avalanches of data so as to support sustainability of this technological trend, which will very likely saturate the current network bandwidth in few years. This paper aims to combine existing technologies and paradigms from the Internet of Things, Cloud, Edge Computing and Big Data into a common framework to enable a shared approach for ISSs at a wide geographical scale, thus envisioning a Global ISS. The proposed solution is based on the idea of pushing data processing tasks as close to data sources as possible, thus increasing security and performance levels, usually critical to surveillance systems. To demonstrate the feasibility and the effectiveness of the proposed approach, the paper presents a case study based on a distributed ISS scenario in a crowded area, implemented on clustered edge devices able to offload tasks in a {\textquoteright}horizontal{\textquoteright} manner. {\textcopyright} 2017 Association for Computing Machinery.

}, keywords = {Big Data, Clouds, Edge, Geographical scale, Information management, Intelligent surveillance systems, Internet of Things, monitoring, Network security, Security and performance, Security systems, Stream processing, Surveillance systems, Technological advances, Technological trends}, doi = {10.1145/3131885.3131918}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047726635\&doi=10.1145\%2f3131885.3131918\&partnerID=40\&md5=a84eba85cc0facc8c5bb0cd664d7d5f0}, author = {Rustem Dautov and Salvatore Distefano and Giovanni Merlino and Dario Bruneo and Francesco Longo and Antonio Puliafito} } @proceedings {Bruneo2017135, title = {User-space network tunneling under a mobile platform: A case study for android environments}, journal = {ADHOC-NOW 2017: Ad-hoc, Mobile, and Wireless Networks}, year = {2017}, note = {cited By 0; Conference of 16th International Conference on Ad-Hoc Networks and Wireless, ADHOC-NOW 2017 ; Conference Date: 20 September 2017 Through 22 September 2017; Conference Code:198729}, pages = {135-143}, publisher = {Springer Verlag}, address = {Messina; Italy; 20-22 September 2017}, abstract = {

The IoT ecosystem is taking the whole ICT world by storm and, in particular for currently hot topics such as Smart Cities, it is becoming one of the key enablers for innovative applications and services. When talking about end users, or even citizens, mobiles enter the picture as the ultimate personal gadget, as well as relevant outlets for most of the duties (sensing, networking, edge computing) IoT devices are typically envisioned in the first place. Smartphones, tablets and similar accessories are even more powerful in terms of hardware capabilities (and function diversity) than typical embedded systems for IoT, but it is typically the software platform (e.g., the OS and SDK) which limits choices for the sake of security and control on the user experience. Even a relatively open environment, such as Android, exhibits these limits, in stark contrast to the otherwise very powerful and feature-complete functionalities the underlying system (i.e., Linux) natively supports. In this work the authors describe a fully user-friendly and platform-compliant approach to let users break free from some of these limitations, in particular with regard to network virtualisation, for the purpose of extending an IoT-ready Smart City use case to mobiles. {\textcopyright} Springer International Publishing AG 2017.

}, keywords = {Ad hoc networks, Android (operating system), Clouds, Computer operating systems, Distributed computer systems, embedded systems, Internet of Things, Mobile ad hoc networks, Network virtualisation, network virtualization, Open environment, OpenStack, Reverse tunneling, Smart city, Software platforms, Stack4Things, Underlying systems, Virtual reality, Virtualization, Wireless ad hoc networks}, isbn = {9783319679099}, issn = {03029743}, doi = {10.1007/978-3-319-67910-5_11}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85030154981\&doi=10.1007\%2f978-3-319-67910-5_11\&partnerID=40\&md5=e898f7c0ffad87eadbefa74a8a7a8940}, author = {Dario Bruneo and Salvatore Distefano and Kostya Esmukov and Francesco Longo and Giovanni Merlino and Antonio Puliafito} } @proceedings {Bruneo2016, title = {Deploying advanced services in the $\#$SmartME infrastructure}, journal = {2016 IEEE 2nd International Forum on Research and Technologies for Society and Industry Leveraging a Better Tomorrow, RTSI 2016}, year = {2016}, note = {cited By 0; Conference of 2nd IEEE International Forum on Research and Technologies for Society and Industry Leveraging a Better Tomorrow, RTSI 2016 ; Conference Date: 7 September 2016 Through 9 September 2016; Conference Code:124837}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Bologna; Italy; 7-9 September 2016}, abstract = {

Smart Cities can be viewed as a complex ecosystem where thousands of {\textquoteright}things{\textquoteright} (e.g., smart objects, vehicles, mobiles) interact with people in order to provide innovative services. Following this view, the $\#$SmartME project aims at creating an horizontal Cloud-based framework enabling developers and users to manage such a complex ecosystem, remotely controlling things as well as virtualizing their functions implementing a provisioning model to scatter the application logic on top of the involved smart objects and to choose with fine granularity which specific tasks to delegate to centralized Cloud infrastructure. After one year from the project kickoff, we present the main architecture by highlighting how advance services can be deployed. {\textcopyright} 2016 IEEE.

}, keywords = {$\#$SmartME, Arduino, Clouds, Ecology, Ecosystems, IaaS, OpenStack, smart cities, Stack4Things}, isbn = {9781509011315}, doi = {10.1109/RTSI.2016.7740633}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006001490\&doi=10.1109\%2fRTSI.2016.7740633\&partnerID=40\&md5=76b3333938151fc341a6f3994a693da8}, author = {Dario Bruneo and Francesco Longo and Giovanni Merlino and Antonio Puliafito and Salvatore Distefano} } @proceedings {Bruneo2016, title = {An IoT Testbed for the Software Defined City Vision: The $\#$SmartMe Project}, journal = {2016 IEEE International Conference on Smart Computing, SMARTCOMP 2016}, year = {2016}, note = {cited By 2; Conference of 2nd IEEE International Conference on Smart Computing, SMARTCOMP 2016 ; Conference Date: 18 May 2016 Through 20 May 2016; Conference Code:122466}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {St. Louis; United States; 18-20 May 2016}, abstract = {

To kickstart the process of morphing Messina into a {\guillemotleft}smart{\guillemotright} city, an explicit mission for the crowdfunded $\#$SmartME project, it is essential to set up an infrastructure of smart devices embedding sensors and actuators, to be scattered all over the urban area. An horizontal framework coupled with the Fog computing approach, by moving logic toward the {\guillemotleft}extreme{\guillemotright} edge of the Internet where data needs to be quickly elaborated, decisions made, and actions performed, is a suitable solution for data- intensive services with time-bound constraints as those usually required by citizens. This is especially true in the context of IoT and Smart City where thousands of smart objects, vehicles, mobiles, people interact to provide innovative services. We thus designed Stack4Things as an OpenStack-based framework spanning the Infrastructure-as-a-Service and Platform-as-a-Service layers. We present some of the core Stack4Things functionalities implementing a Fog computing approach towards a run- time {\guillemotleft}rewireable{\guillemotright} Smart City paradigm, by outlining node management and contextualization mechanisms, also describing its usage in terms of already supported and developed verticals, as well as a specific example related to environmental data collection through $\#$SmartME. {\textcopyright} 2016 IEEE.

}, keywords = {$\#$SmartME, Arduino, Clouds, Computation theory, IaaS, Infrastructure as a service (IaaS), Internet of Things, OpenStack, Platform as a Service (PaaS), smart cities, Stack4Things}, isbn = {9781509008988}, doi = {10.1109/SMARTCOMP.2016.7501678}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84979570937\&doi=10.1109\%2fSMARTCOMP.2016.7501678\&partnerID=40\&md5=c7d8b8c0b0cd880d9c781770a5721acc}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Giovanni Merlino} } @proceedings {Bruneo2017222, title = {IoT-cloud authorization and delegation mechanisms for ubiquitous sensing and actuation}, journal = {2016 IEEE 3rd World Forum on Internet of Things, WF-IoT 2016}, year = {2016}, note = {cited By 0; Conference of 3rd IEEE World Forum on Internet of Things, WF-IoT 2016 ; Conference Date: 12 December 2016 Through 14 December 2016; Conference Code:126414}, pages = {222-227}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Reston; United States; 12-14 December 2016}, abstract = {

In the roadmap for the implementation of ubiquitous computing, ubiquitous sensing and actuation is a milestone still to be reached. It refers to providing sensing and actuation facilities anytime and everywhere. This does not just imply to interconnect sensors and actuators through the Internet, but also and mainly to provide this facilities. IoT-Cloud computing paradigms such as the sensing and actuation as a service one could be a proper way to address this problem. In past work we developed an SAaaS framework extending OpenStack with specific functionalities for resource constrained nodes, Stack4Things. In this paper we focus on access control, authorization and delegation mechanisms which are basic mechanisms for the implementation of the UbSA vision. Thus starting from Stack4Things, we describe how we adapted and extended mechanisms provided by OpenStack, with specific regard to Keystone, with new functionalities for delegation and access control. A use case in the smart city scenario of $\#$SmartME describes the proposed solution in practice. {\textcopyright} 2016 IEEE.

}, keywords = {Access control, Arches, Basic mechanism, cloud computing, Delegation, Delegation mechanisms, Interconnect sensors, Internet of Things, Keystone, OpenStack, Platform as a Service (PaaS), Resource constrained nodes, Sensing and Actuation as a Service, Smart city, Ubiquitous computing}, isbn = {9781509041305}, doi = {10.1109/WF-IoT.2016.7845494}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85015210244\&doi=10.1109\%2fWF-IoT.2016.7845494\&partnerID=40\&md5=055a280adfbce85756d94736e2b82c55}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Giovanni Merlino and Antonio Puliafito} } @proceedings {Bruneo2016, title = {KAOS: A Kinetic Theory Tool for Modeling Complex Social Systems}, journal = {3rd International Conference on Industrial Engineering and Applications, ICIEA 2016}, volume = {68}, year = {2016}, note = {cited By 0; Conference of 2016 3rd International Conference on Industrial Engineering and Applications, ICIEA 2016 ; Conference Date: 28 April 2016 Through 30 April 2016; Conference Code:123080}, publisher = {EDP Sciences}, address = {Hong Kong, 28-30 April 2016}, abstract = {

The kinetic theory approach is successfully used to model complex phenomena related to social systems, allowing to predict the dynamics and emergent behavior of large populations of agents. In particular, kinetic theory for active particles (KTAP) models are usually analyzed by numerically solving the underlying Boltzmann-type differential equations through ad-hoc implementations. In this paper, we present KAOS: a kinetic theory of active particles modeling and analysis software tool. To the best of our knowledge, KAOS represents the first attempt to design and implement a comprehensive tool that assists the user in all the steps of the modeling process in the framework of the kinetic theories, from the model definition to the representation of transient solutions. To show the KAOS features, we present a new model capturing the competition/cooperation dynamics of a socio-economic system with welfare dynamics, in different socio-political conditions. {\textcopyright} 2016 The Authors, published by EDP Sciences.

}, issn = {2261236X}, doi = {10.1051/matecconf/20166816004}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84982168597\&doi=10.1051\%2fmatecconf\%2f20166816004\&partnerID=40\&md5=87f3509a3d879faddfe7cc858a349db5}, author = {Dario Bruneo and Marina Dolfin and Francesco Longo and Marco Scarpa and Antonio Puliafito} } @proceedings {Merlino2017213, title = {Quantitative evaluation of Cloud-based network virtualization mechanisms for IoT}, journal = {ValueTools 2016 - 10th EAI International Conference on Performance Evaluation Methodologies and Tools}, year = {2016}, note = {cited By 0; Conference of 10th EAI International Conference on Performance Evaluation Methodologies and Tools, ValueTools 2016 ; Conference Date: 25 October 2016 Through 28 October 2016; Conference Code:127816}, pages = {213-216}, publisher = {Association for Computing Machinery}, address = {Taormina; Italy; 25-28 October 2016}, abstract = {

Integration of the Internet of Things (IoT) with the Cloud may lead to a range of different architectures and solutions. Our efforts in this domain are mainly geared towards making IoT systems available as service-oriented infrastructure. Under Infrastructure-as-a-Service (IaaS) scenarios, network virtualization is a core building block of any solution, even more so for IoT-focused Cloud providers. Enabling mechanisms are required to support virtualization of the networking facilities for IoT resources that are managed by the Cloud. This work describes an approach to network virtualization based on popular off-the-shelf tools and protocols in place of application-specific logic, acting as a blueprint in the design of the Stack4Things architecture, an OpenStack-derived framework to provide IaaS-like services from a pool of IoT devices. We quantitatively evaluate the underlying mechanisms demonstrating that the proposed approach exhibits mostly comparable performance with respect to standard technologies for virtual private networks, or at least good enough for the kind of underlying hardware, e.g., smart boards, whilst still representing a more flexible solution. Copyright {\textcopyright} 2016 EAI.

}, keywords = {Application specific, Clouds, Distributed computer systems, Infrastructure as a service (IaaS), Internet of thing (IOT), Internet of Things, Network architecture, network virtualization, OpenStack, Performance evaluation, Platform as a Service (PaaS), Quantitative evaluation, Reverse tunneling, Service-oriented infrastructures, Virtual private networks, Virtual reality, Virtualization}, isbn = {9781631901416}, doi = {10.4108/eai.25-10-2016.2266600}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85021354856\&doi=10.4108\%2feai.25-10-2016.2266600\&partnerID=40\&md5=61d1e54a06f72746e6e5bd90c920b1c0}, author = {Giovanni Merlino and Francesco Longo and Salvatore Distefano and Dario Bruneo and Antonio Puliafito} } @proceedings {Ghosh2017227, title = {Resiliency quantification for large scale systems: An IaaS cloud use case}, journal = {ValueTools 2016 - 10th EAI International Conference on Performance Evaluation Methodologies and Tools}, year = {2016}, note = {cited By 0; Conference of 10th EAI International Conference on Performance Evaluation Methodologies and Tools, ValueTools 2016 ; Conference Date: 25 October 2016 Through 28 October 2016; Conference Code:127816}, pages = {227-234}, publisher = {Association for Computing Machinery}, address = {Taormina; Italy; 25-28 October 2016}, abstract = {

We quantify the resiliency of large scale systems upon changes encountered beyond the normal system behavior. General steps for resiliency quantification are shown and resiliency metrics are defined to quantify the effects of changes. The proposed approach is illustrated through an Infrastructureas-a-Service (IaaS) Cloud use case. Specifically, we assess the impact of changes in demand and available capacity on the Cloud resiliency using interacting state-space based submodels. Since resiliency quantification involves understanding the transient behavior of the system, fixed-point variables evolve with time leading to non-homogenous Markov chains. In this paper, we present an algorithm for resiliency analysis when dealing with such non-homogenous sub-models. A comparison is shown with our past research, where we quantified the resiliency of IaaS Cloud performance using a one level monolithic model. Numerical results show that the approach proposed in this paper can scale for a real sized Cloud without significantly compromising the accuracy. Copyright {\textcopyright} 2016 EAI.

}, keywords = {Available capacity, Chains, Clouds, Homogenous Markov chain, Impact of changes, Infrastructure as a service (IaaS), Large scale systems, Markov processes, Non-homogeneous, Numerical results, Resiliency, Submodels, Transient behavior}, isbn = {9781631901416}, doi = {10.4108/eai.25-10-2016.2266805}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85021320622\&doi=10.4108\%2feai.25-10-2016.2266805\&partnerID=40\&md5=a6167b2554cad8a9aae02963254c8b52}, author = {Rahul Ghosh and Francesco Longo and Vijay K. Naik and A.J. Rindos and Kishor Trivedi} } @proceedings {Bruneo2016848, title = {Stack4Things as a fog computing platform for Smart City applications}, journal = {Proceedings - IEEE INFOCOM}, volume = {2016-September}, year = {2016}, note = {cited By 1; Conference of 35th IEEE Conference on Computer Communications Workshops, INFOCOM WKSHPS 2016 ; Conference Date: 10 April 2016 Through 14 April 2016; Conference Code:123666}, pages = {848-853}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {San Francisco; United States; 10-14 April 2016}, abstract = {

Fog computing envisions computation logic to be moved at the edge of the Internet where data needs to be quickly elaborated, decisions made, and actions performed. Delegating to the Cloud the whole burden of applications could not be efficient indeed, for example in case of workload bursts. This is especially true in the context of IoT and Smart City where thousands of smart objects, vehicles, mobiles, people interact to provide innovative services. We thus designed Stack4Things as an OpenStack-based framework spanning the Infrastructure-as-a-Service and Platform-as-a-Service layers. It enables developers and users to manage an IoT infrastructure, remotely controlling nodes as well as virtualizing their functions and creating network overlays among them, implementing a provisioning model for Cyber-Physical Systems. Moreover, it provides mechanisms to scatter the application logic on top of the involved smart objects and to choose with fine granularity which specific tasks to delegate to centralized Cloud infrastructure. In this paper, we show the core Stack4Things mechanisms implementing a Fog computing approach towards a run-time {\textquoteright}rewireable{\textquoteright} Smart City paradigm. We demonstrate its effectiveness in a smart mobility scenario where vehicles interact with City-level smart objects to provide end users with highly responsive geolocalised services. {\textcopyright} 2016 IEEE.

}, isbn = {9781467399555}, issn = {0743166X}, doi = {10.1109/INFCOMW.2016.7562195}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988813645\&doi=10.1109\%2fINFCOMW.2016.7562195\&partnerID=40\&md5=029527b7cfabd94a2e46f0a1af643b6e}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Giovanni Merlino and Antonio Puliafito and Valeria D{\textquoteright}Amico and Marco Sapienza and Giuseppe Torrisi} } @proceedings {Distefano2017, title = {A Stack4Things-based platform for mobile crowdsensing services}, journal = {Proceedings of the 2016 ITU Kaleidoscope Academic Conference: ICTs for a Sustainable World, ITU WT 2016}, year = {2016}, note = {cited By 0; Conference of 2016 ITU Kaleidoscope Academic Conference, ITU WT 2016 ; Conference Date: 14 November 2016 Through 16 November 2016; Conference Code:125881}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Bangkok; Thailand; 14-16 November 2016}, abstract = {

As mobiles grow pervasive in people{\textquoteright}s lives and expand their reach, Mobile CrowdSensing (MCS) and similar paradigms are going to play an ever more prominent role. There is a pressing need then to ease developers and service providers in embracing the opportunity, and that means offering a platform for such efforts. This in turn means providing a solid foundational architecture with abstractions and sound layering for MCS application designs to be mapped over it. This should base on a flexible infrastructure able to provide resources to MCS applications according to their requirements, hopefully on-demand. A service-oriented/Cloud model can perfectly fill this gap. This paper is a first step in this direction, proposing to adopt Stack4Things (S4T), an OpenStack-based platform for managing sensing and IoT nodes, for runtime customization of resources and their functions to support MCS services and applications. This implies developing and extending the S4T platform further to the specific requirements coming from off-the-shelf, e.g., Android-based, mobiles, as well as describing an example S4T-powered MCS application, Pothole Detection Mapping, to highlight the role of the platform. {\textcopyright} 2016 International Telecommunication Union.

}, keywords = {Android, Android (operating system), Application design, Clouds, Internet of Things, Mobile Crowdsensing, On demands, OpenStack, Platform as a Service (PaaS), Service Oriented, Service provider, Services and applications}, isbn = {9789261204310}, doi = {10.1109/ITU-WT.2016.7805722}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85014231645\&doi=10.1109\%2fITU-WT.2016.7805722\&partnerID=40\&md5=ea474a8f0a90e12de36e3ae371c16d9b}, author = {Salvatore Distefano and Antonio Puliafito and Giovanni Merlino and Francesco Longo and Dario Bruneo} } @proceedings {Bruneo2015797, title = {Analytical Modeling of Reactive Autonomic Management Techniques in IaaS Clouds}, journal = {Proceedings - 2015 IEEE 8th International Conference on Cloud Computing, CLOUD 2015}, year = {2015}, note = {cited By 2; Conference of 8th IEEE International Conference on Cloud Computing, CLOUD 2015 ; Conference Date: 27 June 2015 Through 2 July 2015; Conference Code:116940}, pages = {797-804}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {New York (USA)}, abstract = {

Cloud computing infrastructures provide services to a wide number of users whose behavior can deeply change at the occurrence of particular events. To correctly handle such situations a cloud infrastructure have to be reconfigured in a way that does not cause degradation in the overall performance. Otherwise, the quality of service specified in the service level agreement could be violated. To prevent such situations, the infrastructure could be organized as an autonomic system where self-adaptation and self-configuration techniques are implemented. Appropriate design choices become important in order not to fail in this goal. We propose a technique, based on a Petri net model and a specific analytical analysis approach, to represent Infrastructure-as-a-Service (IaaS) systems in the case in which the load conditions can suddenly change and reactive autonomic management techniques are applied to mitigate the consequences of the change. The model we propose is able to appropriately evaluate performance metrics in such critical situations making it suitable as a design tool for IaaS cloud systems. {\textcopyright} 2015 IEEE.

}, keywords = {Autonomic management, cloud computing, Cloud computing infrastructures, Cloud infrastructures, Iaas clouds, Industrial management, Infrastructure as a service (IaaS), Performance metrics, Petri nets, Quality of service, Resiliency, Service Level Agreements, Stochastic reward nets, Stochastic systems}, isbn = {9781467372879}, doi = {10.1109/CLOUD.2015.110}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84960155425\&doi=10.1109\%2fCLOUD.2015.110\&partnerID=40\&md5=2aa09923889aea0bc667deb1d6d250d8}, author = {Dario Bruneo and Francesco Longo and Rahul Ghosh and Marco Scarpa and Antonio Puliafito and Kishor Trivedi} } @proceedings {Merlino2015199, title = {Cloud-based network virtualization: An IoT use case}, journal = {Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST}, volume = {155}, year = {2015}, note = {cited By 2; Conference of 7th International Conference on Ad Hoc Networks, AdHocHets 2015 ; Conference Date: 1 September 2015 Through 2 September 2015; Conference Code:139059}, pages = {199-210}, publisher = {Springer Verlag}, address = {San Remo (Italy)}, abstract = {

In light of an overarching scheme about extending the capabilities of Internet of things (IoT) with Cloud-enabled mechanisms, network virtualization is a key enabler of infrastructure-oriented IoT solutions. In particular, without network virtualization infrastructure cannot really be considered flexible enough to meet emerging requirements, and even administrative duties, such as management, maintenance and large-scale automation, would turn out to be brittle and addressed by special casing, leading to loss of generality and a variety of corner cases. We propose a Cloud-based network virtualization approach for IoT, based on the Open- Stack IaaS framework, where its networking subsystem, Neutron, gets extended to accomodate virtual networks and arbitrary topologies among virtualmachines and globally dispersed smart objects, whichever the setup and constraints of the underlying physical networks. This work outlines a motivating use case for our approach, and the ensuing discussion is provided to frame the benefits of the underlying design. {\textcopyright} Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2015.

}, keywords = {Ad hoc networks, Arbitrary topology, Clouds, Internet of Things, Internet of Things (IOT), IoT, network virtualization, OpenStack, Telecommunication networks, Underlying physical networks, Virtual networks, Virtual reality, WebSocket}, isbn = {9783319250663}, issn = {18678211}, doi = {10.1007/978-3-319-25067-0_16}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84947982973\&doi=10.1007\%2f978-3-319-25067-0_16\&partnerID=40\&md5=f749a4988e888d00cbdabf0649881264}, author = {Giovanni Merlino and Dario Bruneo and Francesco Longo and Salvatore Distefano and Antonio Puliafito} } @article {Longo2015280, title = {Dependability modeling of Software Defined Networking}, journal = {Computer Networks}, volume = {83}, year = {2015}, note = {cited By 6}, pages = {280-296}, publisher = {Elsevier}, abstract = {

Software Defined Networking (SDN) is a new network design paradigm that aims at simplifying the implementation of complex networking infrastructures by separating the forwarding functionalities (data plane) from the network logical control (control plane). Network devices are used only for forwarding, while decisions about where data is sent are taken by a logically centralized yet physically distributed component, i.e., the SDN controller. From a quality of service (QoS) point of view, an SDN controller is a complex system whose operation can be highly dependent on a variety of parameters, e.g., its degree of distribution, the corresponding topology, the number of network devices to control, and so on. Dependability aspects are particularly critical in this context. In this work, we present a new analytical modeling technique that allows us to represent an SDN controller whose components are organized in a hierarchical topology, focusing on reliability and availability aspects and overcoming issues and limitations of Markovian models. In particular, our approach allows to capture changes in the operating conditions (e.g., in the number of managed devices) still allowing to represent the underlying phenomena through generally distributed events. The dependability of a use case on a two-layer hierarchical SDN control plane is investigated through the proposed technique providing numerical results to demonstrate the feasibility of the approach. {\textcopyright} 2015 Elsevier B.V.

}, keywords = {Availability, Complex networks, Controllers, Degree of distributions, Distributed components, Electric network topology, Information dissemination, Markov processes, Networking infrastructure, Non-Markovian, Quality control, Quality of service, Random processes, Reliability, Reliability and availability, Software defined networking (SDN), Software reliability, Software-defined networkings, Stochastic models, Stochastic systems, Topology, Type expansions}, issn = {13891286}, doi = {10.1016/j.comnet.2015.03.018}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84946489290\&doi=10.1016\%2fj.comnet.2015.03.018\&partnerID=40\&md5=b4f32c89d2b7b79fefcaf97082764960}, author = {Francesco Longo and Salvatore Distefano and Dario Bruneo and Marco Scarpa} } @proceedings {Bruneo201524, title = {Enabling collaborative development in an open stack testbed: The cloud wave use case}, journal = {Proceedings of the 7th International Workshop on Principles of Engineering Service-Oriented and Cloud Systems (PESOS 2015)}, year = {2015}, note = {cited By 0; Conference of 7th International Workshop on Principles of Engineering Service-Oriented and Cloud Systems, PESOS 2015 ; Conference Date: 23 May 2015; Conference Code:117285}, pages = {24-30}, publisher = {IEEE Computer Society}, address = {Florence, Italy, 23 May 2015 - }, abstract = {

The Cloud Wave project embodies a challenging set of goals, including the development of software components that have to be integrated into a single multi-layer Cloud stack based on Open Stack, while cutting across the Infrastructure-as-a-Service, Platform-as-a-Service, and Software-as-a-Service levels by targeting layer-spanning issues such as Feedback-Driven Development and Coordinated Adaptation. A DevOps-ready test bed environment should allow project partners to exert full control over deployed compo entry and collaborate on development. Goals include providing a flexible infrastructure capable of emulating several multi-node Cloud environments, as well as enabling the automatic deployment of Cloud Wave artifacts into such environment in order to simplify integration activities. This paper takes a snapshot of the current situation with regards to the design and implementation of such a setup, trying to gain relevant insight out of this effort. {\textcopyright} 2015 IEEE.

}, keywords = {Automatic deployments, cloud computing, Collaborative development, Continuous integrations, Design and implementations, DevOps, Distributed computer systems, Infrastructure as a service (IaaS), Integration, OpenStack, Platform as a Service (PaaS), Software as a service (SaaS), Test bed environment, Testbeds, Virtual infrastructures}, isbn = {9781479919345}, issn = {21567921}, doi = {10.1109/PESOS.2015.12}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84955273627\&partnerID=40\&md5=3fed56f69ce2ffdc46abcdf129e1e355}, author = {Dario Bruneo and Francesco Longo and Giovanni Merlino and Nicola Peditto and Carmelo Romeo and Fabio Verboso and Antonio Puliafito} } @proceedings {Merlino2015268, title = {Enabling mechanisms for Cloud-based network virtualization in IoT}, journal = {IEEE World Forum on Internet of Things, WF-IoT 2015 - Proceedings}, year = {2015}, note = {cited By 3; Conference of 2nd IEEE World Forum on Internet of Things, WF-IoT 2015 ; Conference Date: 14 December 2015 Through 16 December 2015; Conference Code:119271}, pages = {268-273}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Milan (Italy)}, abstract = {

As part of a wider effort in integrating Internet of things (IoT) with the Cloud under the guise of infrastructure to be provided as-a-Service, network virtualization plays an essential role, both as an enabler of Infrastructure-as-a-Service scenarios and as a basic building block of the solution for the IoT-focused Cloud provider. Virtualization of the networking facilities for Cloud-managed IoT resources needs mechanisms to deal with the inherent complexity. This work outlines an implementation-agnostic approach to such a problem, reflected in our evolving Stack4Things architecture, derived from OpenStack, and implemented starting from such codebase, by leveraging also a choice of modern tooling and protocols. A specific use case and the discussion that follows are provided to frame the benefits of this strategy. {\textcopyright} 2015 IEEE.

}, keywords = {Basic building block, Cloud providers, Clouds, Complex networks, Infrastructure as a service (IaaS), Inherent complexity, Internet, Internet of Things, Internet of Things (IOT), Network architecture, network virtualization, OpenStack, Virtual reality, Virtualizations, WebSocket}, isbn = {9781509003655}, doi = {10.1109/WF-IoT.2015.7389064}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84964453184\&doi=10.1109\%2fWF-IoT.2015.7389064\&partnerID=40\&md5=555a2a5aad4f3af24fac04fc0e4a8280}, author = {Giovanni Merlino and Dario Bruneo and Salvatore Distefano and Francesco Longo and Antonio Puliafito} } @proceedings {Bruneo201562, title = {A framework for the 3-D cloud monitoring based on data stream generation and analysis}, journal = {Proceedings of the 2015 IFIP/IEEE International Symposium on Integrated Network Management (IM)}, year = {2015}, note = {cited By 0; Conference of 14th IFIP/IEEE International Symposium on Integrated Network Management, IM 2015 ; Conference Date: 11 May 2015 Through 15 May 2015; Conference Code:113524}, pages = {62-70}, publisher = {IEEE Computer Society}, address = {Ottawa, Canada, 11-15 May 2015}, abstract = {

Cloud monitoring is one important aspect for effective cloud management. Currently, cloud monitoring solutions can be classified into three groups: the ones not considering multiple layers or real time data analysis, the ones considering multiple layers but not real time data analysis, and the ones only considering real time data analysis. However, all these solutions fail to provide frameworks able to combine together monitoring in multiple layers and data stream analysis for detecting situations where multiple management actions are applicable in different layers of the cloud environment. This paper addresses this gap and proposes the Ceiloesper framework. Such a framework extends the OpenStack Ceilometer technology with Esper CEP and enables collection and analysis of information according to the principles defined in the 3-D cloud monitoring model, proposed in a previous work. The main contributions of this paper are: (i) the definition of the concept of Situation of Interest (SoI) leading to multiple management actions; (ii) the Ceiloesper architecture for a monitoring solution combining traditional monitoring elements with CEP; (iii) extensions to the Ceilometer OpenStack technology. We tested the Ceiloesper framework on a scenario based on the Wordpress application and the experimental results show its effectiveness. {\textcopyright} 2015 IEEE.

}, keywords = {Cloud environments, Cloud managements, Cloud monitoring, Data communication systems, Data handling, Data stream, Different layers, Information analysis, Meteorological instruments, monitoring, Multiple layers, Network management, Real time data analysis, Scenario-based}, isbn = {9783901882760}, doi = {10.1109/INM.2015.7140277}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84942574737\&partnerID=40\&md5=9727c6a66767d639f5c5cfd3bd7d96c9}, author = {Dario Bruneo and Francesco Longo and Clarissa Marquezan} } @article {Bruneo20153052, title = {Modeling and Evaluation of Energy Policies in Green Clouds}, journal = {IEEE Transactions on Parallel and Distributed Systems}, volume = {26}, number = {11}, year = {2015}, note = {cited By 0}, pages = {3052-3065}, publisher = {IEEE Computer Society}, abstract = {

Following the as-a-service philosophy, a cloud service provider offers computing utilities in the form of virtual resources instantiated on top of a physical infrastructure. In order to meet business requirements still providing high-quality services, performance evaluation needs to be carefully carried out with the aim of optimizing data center utilization and increasing user satisfaction. In this context, power efficiency plays a critical role pushing service providers towards the application of innovative green strategies. In this paper, we present an analytical framework, based on stochastic reward nets, that allows to evaluate different resource allocation policies in a green cloud. A use case is shown in order to illustrate the approach, modeling scattering and saturation allocation policies and comparing them to a purely physical data center scenario. A validation of the proposed model against the CloudSim framework is presented and several numerical results are provided, demonstrating the effectiveness of the approach as a powerful tool for a cloud service provider to perform well-informed decisions about theresource allocation policies to be enforced. {\textcopyright} 1990-2012 IEEE.

}, keywords = {Allocation policies, Business requirement, cloud computing, Cloud service providers, Distributed database systems, Green Computing, High quality service, Performance evaluation, Quality control, Resource allocation, Resource allocation policy, Stochastic reward nets, Stochastic systems}, issn = {10459219}, doi = {10.1109/TPDS.2014.2364194}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84944075521\&partnerID=40\&md5=ee939ccd602bffca9ab90abdfd8285d9}, author = {Dario Bruneo and Audric Lhoas and Francesco Longo and Antonio Puliafito} } @proceedings {Bruneo20157, title = {A modular approach to collaborative development in an OpenStack testbed}, journal = {Proceedings - IEEE 4th Symposium on Network Cloud Computing and Applications, NCCA 2015}, year = {2015}, note = {cited By 0; Conference of 4th IEEE Symposium on Network Cloud Computing and Applications, NCCA 2015 ; Conference Date: 11 June 2015 Through 12 June 2015; Conference Code:118462}, pages = {7-14}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Munich (Germany)}, abstract = {

CloudWave is an Integrated Project funded by the European Commission whose aim is to provide a new powerful foundation for the development, deployment, and management of Cloud-based services. CloudWave will develop a set of software components that have to be integrated into a single multi-layer Cloud stack based on OpenStack. During the project, a testbed environment allows project partners to exert full control over deployed componentry and collaborate on development. Among testbed requirements, the most interesting ones include providing a flexible infrastructure capable of emulating several multi-node Cloud environments and enabling the automatic deployment of CloudWave artifacts into such environment during integration phases. This paper provides a high-level description of the testbed design and implementation focusing on the technologies exploited to meet such requirements. {\textcopyright} 2015 IEEE.

}, isbn = {0769556035; 9780769556031}, doi = {10.1109/NCCA.2015.12}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84960382584\&doi=10.1109\%2fNCCA.2015.12\&partnerID=40\&md5=cc9dbeb0086a3b696be463c6bbeb5d3a}, author = {Dario Bruneo and Francesco Longo and Giovanni Merlino and Nicola Peditto and Carmelo Romeo and Fabio Verboso and Antonio Puliafito} } @proceedings {Bruneo2016175, title = {Multi-level adaptations in a CloudWave infrastructure: A telco use case}, journal = {European Conference on Service-Oriented and Cloud Computing}, volume = {567}, year = {2015}, note = {cited By 1; Conference of Workshops on CLIoT, WAS4FI, SeaClouds, CloudWay, IDEA, FedCloudNet 2015 held in conjunction with European Conference on Service-Oriented and Cloud Computing, ESOCC 2015 ; Conference Date: 15 September 2015 Through 17 September 2015; Conference Code:174149}, pages = {175-183}, publisher = {Springer Verlag}, address = {Taormina (Italy)}, abstract = {

CloudWave is a FP7 EU project whose aim is delivering novel technologies and methods for improving both the development of Cloud services and the management of their operation and execution. Such goal is reached by providing mechanisms and policies for coordinating multiple adaptations both at the level of the Cloud infrastructure and at the level of the hosted applications. In this paper, we describe the CloudWave Telco application use case and we provide a proof of concept discussing how the QoS experienced by the application users can be improved thanks to the technologies provided by CloudWave. {\textcopyright} Springer International Publishing Switzerland 2016.

}, keywords = {cloud computing, Cloud infrastructures, Cloud services, Eu projects, Multilevels, Multiple adaptation, Proof of concept, Quality of service}, isbn = {9783319333120}, issn = {18650929}, doi = {10.1007/978-3-319-33313-7_13}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84966667439\&doi=10.1007\%2f978-3-319-33313-7_13\&partnerID=40\&md5=00474a6170ba9f89b97c8a7ef8c59fce}, author = {Dario Bruneo and Francesco Longo and Boris Moltchanov} } @article {Distefano2015629, title = {QoS Assessment of Mobile Crowdsensing Services}, journal = {Journal of Grid Computing}, volume = {13}, number = {4}, year = {2015}, note = {cited By 2}, pages = {629-650}, publisher = {Springer Netherlands}, abstract = {

The wide spreading of smart devices drives to develop distributed applications of increasing complexity, attracting efforts from both research and business communities. Recently, a new volunteer contribution paradigm based on participatory and opportunistic sensing is affirming in the Internet of Things scenario: Mobile Crowdsensing (MCS). A typical MCS application considers smart devices as contributing sensors able to produce geolocalized data about the physical environment, then collected by a remote application server for processing. The growing interest on MCS allows to think about its possible exploitation in commercial context. This calls for adequate methods able to support MCS service providers in design choices, implementing mechanisms for the quality of service (QoS) assessment while dealing with complex time-dependent phenomena and churning issues due to contributors that unpredictably join and leave the MCS system. In this paper, we propose an analytical modeling framework based on stochastic Petri nets to evaluate QoS metrics of a class of MCS services. This method requires to extend the Petri net formalism by specifying a marking dependency semantics for non-exponentially distributed transitions. The approach is then applied to an MCS application example deriving some QoS measures that can drive quantitative evaluation and characterization of the {\textquotedblleft}crowd{\textquotedblright} behavior. {\textcopyright} 2015, Springer Science+Business Media Dordrecht.

}, keywords = {crowdsensing, Digital storage, Distributed applications, Marking dependency, Non-Markovian, Performability, Petri nets, Quality of service, Quality of service (QoS) assessments, Quantitative evaluation, Semantics, Stochastic systems, Time dependent phenomena}, issn = {15707873}, doi = {10.1007/s10723-015-9338-7}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958155341\&doi=10.1007\%2fs10723-015-9338-7\&partnerID=40\&md5=3bd7e36a37ab06a3acabb37a21b90ab1}, author = {Salvatore Distefano and Francesco Longo and Marco Scarpa} } @inbook {Longo2015256, title = {A simulated annealing-based approach for the optimization of routine maintenance interventions}, booktitle = {Lecture Notes in Business Information Processing}, volume = {241}, year = {2015}, note = {cited By 0; Conference of 17th International Conference on Enterprise Information Systems, ICEIS 2015 ; Conference Date: 27 April 2015 Through 30 April 2015; Conference Code:164419}, pages = {256-279}, publisher = {Springer Verlag}, organization = {Springer Verlag}, abstract = {

Metaheuristics are often adopted to solve optimization problems where some requests need to be scheduled among a finite number of resources, i. e., the so called scheduling problems. Such techniques approach the optimization problems by taking inspiration from a certain physical phenomenon. Simulated annealing is a metaheuristic approach inspired to the controlled cooling of a material from a high temperature to a state in which internal defects of the crystals are minimized. In this paper, we use a simulated annealing-based approach to solve the problem of the scheduling of geographically distributed routine maintenance interventions. Each intervention has to be assigned to a maintenance team and the choice among the available teams and the order in which interventions are performed by each team are based on team skills, cost of overtime work, and cost of transportation. We compare our solution algorithm versus an exhaustive approach. First, we consider a real industrial use case and show several numerical results to analyze the effect of the parameters of the simulated annealing on the accuracy of the solution and on the execution time of the algorithm. Then, we provide results varying the parameters and dimension of the considered problem highlighting how they affect reliability and efficiency of our algorithm. {\textcopyright} Springer International Publishing Switzerland 2015.

}, keywords = {Cost of transportation, Industrial use case, Information systems, Maintenance, Meta-heuristic approach, Optimization, Optimization problems, parameter estimation, Physical phenomena, Problem solving, Routine maintenance, Scheduling, Scheduling problem, Simulated annealing, Solution algorithms}, isbn = {9783319291321}, issn = {18651348}, doi = {10.1007/978-3-319-29133-8_13}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958970833\&doi=10.1007\%2f978-3-319-29133-8_13\&partnerID=40\&md5=38ef9117d84652f8dfd7526db0dba19c}, author = {Francesco Longo and Andrea Lotronto and Marco Scarpa and Antonio Puliafito} } @article {Merlino201516314, title = {A smart city lighting case study on an OpenStack-powered infrastructure}, journal = {Sensors}, volume = {15}, number = {7}, year = {2015}, note = {cited By 0}, pages = {16314-16335}, publisher = {MDPI AG}, abstract = {

The adoption of embedded systems, mobile devices and other smart devices keeps rising globally, and the scope of their involvement broadens, for instance, in smart city-like scenarios. In light of this, a pressing need emerges to tame such complexity and reuse as much tooling as possible without resorting to vertical ad hoc solutions, while at the same time taking into account valid options with regard to infrastructure management and other more advanced functionalities. Existing solutions mainly focus on core mechanisms and do not allow one to scale by leveraging infrastructure or adapt to a variety of scenarios, especially if actuators are involved in the loop. A new, more flexible, cloud-based approach, able to provide device-focused workflows, is required. In this sense, a widely-used and competitive framework for infrastructure as a service, such as OpenStack, with its breadth in terms of feature coverage and expanded scope, looks to fit the bill, replacing current application-specific approaches with an innovative application-agnostic one. This work thus describes the rationale, efforts and results so far achieved for an integration of IoT paradigms and resource ecosystems with such a kind of cloud-oriented device-centric environment, by focusing on a smart city scenario, namely a park smart lighting example, and featuring data collection, data visualization, event detection and coordinated reaction, as example use cases of such integration. {\textcopyright} 2015 by the authors; licensee MDPI, Basel, Switzerland.

}, keywords = {AMQP, Ceilometer, CEP, Clouds, CoAP, Coordination reactions, data visualization, embedded systems, IaaS, Infrastructure as a service (IaaS), IoT, Lighting, Meteorological instruments, Mobile devices, MOM, OpenStack, REST, smart cities}, issn = {14248220}, doi = {10.3390/s150716314}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84940184863\&partnerID=40\&md5=6b5fc8b27ed3943f0529cb3323f22e88}, author = {Giovanni Merlino and Dario Bruneo and Salvatore Distefano and Francesco Longo and Antonio Puliafito and Adnan H. Al-Anbuky} } @proceedings {Merlino2015909, title = {Software defined cities: A novel paradigm for smart cities through IoT clouds}, journal = {Proceedings - 2015 IEEE 12th International Conference on Ubiquitous Intelligence and Computing, 2015 IEEE 12th International Conference on Advanced and Trusted Computing, 2015 IEEE 15th International Conference on Scalable Computing and Communications, 20}, year = {2015}, note = {cited By 1; Conference of Proceedings - 2015 IEEE 12th International Conference on Ubiquitous Intelligence and Computing, 2015 IEEE 12th International Conference on Advanced and Trusted Computing, 2015 IEEE 15th International Conference on Scalable Computing and Communications, 2015 IEEE International Conference on Cloud and Big Data Computing, 2015 IEEE International Conference on Internet of People and Associated Symposia/Workshops, UIC-ATC-ScalCom-CBDCom-IoP 2015 ; Conference Date: 10 August 2015 Through 14 August 2015; Conference Code:122811}, pages = {909-916}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Beijing (China)}, abstract = {

A Smart City represents an improvement of today cities that strategically exploits many smart factors to increase the city sustainable growth and strengthen city functions, while ensuring citizen quality of life and health. Cities can be perceived as an ecosystem of "things" which citizens daily interact with: street furniture, public buildings, transportation, monuments, public lighting as well as personal smartphones. Thanks to recent advances in ICT such things can be considered always interconnected also providing sensing and actuating facilities according to the Internet of Things and Cyber Physical Systems models. Creating smart services that exploit such a complex infrastructure is a fundamental and current challenge. To this end, aim of this paper is the design and implementation of the Software Defined Cities approach: a Cloud-based infrastructure that, starting from the well known concept of Software Defined paradigms, is able to transform this complex ecosystem in a simple and "programmable" environment where municipalities, companies, scientists, and citizens can easily collaborate in developing innovative smart services. The overall architecture is presented focusing on both the function virtualization and infrastructure aspects also giving details about the software stacks used (e.g., Open Stack) while a use case is laid out to demonstrate the advantages of the proposed approach. {\textcopyright} 2015 IEEE.

}, keywords = {Big Data, Clouds, Complex ecosystems, Complex infrastructures, Cyber physical systems (CPSs), Design and implementations, Ecology, Ecosystems, embedded systems, Internet, Internet of Things, Sensing and actuating, smart cities, Sustainable development, Sustainable growth, Trusted Computing, Ubiquitous computing, Virtual reality, Virtualizations}, isbn = {9781467372114}, doi = {10.1109/UIC-ATC-ScalCom-CBDCom-IoP.2015.174}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983438378\&doi=10.1109\%2fUIC-ATC-ScalCom-CBDCom-IoP.2015.174\&partnerID=40\&md5=790a6042e6e80594e42b64695d6b014e}, author = {Giovanni Merlino and Dario Bruneo and Francesco Longo and Antonio Puliafito and Salvatore Distefano} } @proceedings {Bruneo201598, title = {An SRN-based resiliency quantification approach}, journal = {Proceedings of the 36th International Conference on Application and Theory of Petri Nets and Concurrency (Petri Nets)}, volume = {9115 Lecture Notes in Computer Science}, year = {2015}, note = {cited By 0; Conference of 36th International Conference on Application and Theory of Petri Nets and Concurrency, Petri Nets 2015 ; Conference Date: 21 June 2015 Through 26 June 2015; Conference Code:119609}, pages = {98-116}, publisher = {Springer Verlag}, address = {Brussels, Belgium, 21-26 June 2015}, abstract = {

Resiliency is often considered as a synonym for faulttolerance and reliability/availability. We start from a different definition of resiliency as the ability to deliver services when encountering unexpected changes. Semantics of change is of extreme importance in order to accurately capture the real behavior of a system. We propose a resiliency analysis technique based on stochastic reward nets that allows the modeler: (1) to reuse an already existing dependability or performance model for a specific system with minimal modifications, and (2) to adapt the given model for specific change semantics. To automate the model analysis an algorithm is designed and the modeler is provided with a formalism that corresponds to the semantics. Our algorithm and approach is implemented to demonstrate the proposed resiliency quantification approach. Finally, we discuss the differences between our approach and an alternative technique based on deterministic and stochastic Petri nets and highlight the advantages of the proposed approach in terms of semantics specification. {\textcopyright} Springer International Publishing Switzerland 2015.

}, keywords = {Analysis techniques, Deterministic and stochastic Petri nets, Model analysis, Performance Model, Petri nets, Resiliency, Semantics, Stochastic models, Stochastic reward nets, Stochastic systems}, isbn = {9783319194875}, issn = {03029743}, doi = {10.1007/978-3-319-19488-2_5}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84937428490\&partnerID=40\&md5=7d0bbe99afba1a79df65b4e35e86a02c}, author = {Dario Bruneo and Francesco Longo and Marco Scarpa and Antonio Puliafito and Rahul Ghosh and Kishor S. Trivedi} } @proceedings {Longo2015204, title = {Stack4Things: An OpenStack-Based Framework for IoT}, journal = {Proceedings - 2015 International Conference on Future Internet of Things and Cloud, FiCloud 2015 and 2015 International Conference on Open and Big Data, OBD 2015}, year = {2015}, note = {cited By 2; Conference of 3rd International Conference on Future Internet of Things and Cloud, FiCloud 2015 ; Conference Date: 24 August 2015 Through 26 August 2015; Conference Code:117067}, pages = {204-211}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, address = {Rome (Italy)}, abstract = {

In the wake of the massive adoption of embedded systems, mobiles, and other smart devices, as the scope of their involvement keeps broadening, complexity may quickly become overwhelming and vertical ad-hoc solutions will not cut it anymore. We propose to reuse as much tooling as possible, taking into account suitable options with regard to infrastructure management, then piggybacking as much advanced functionalities as possible in such kind of environment. In this sense, a widely used and competitive framework for Infrastructure-as-a-Service such as OpenStack, with its breadth in terms of feature coverage and expanded scope, looks like fitting the bill. This work therefore describes the approach and the solutions so far preliminary implemented for enabling Cloud-mediated interactions with droves of sensor-and actuator-hosting nodes by proposing Stack4Things, a framework for Sensing-and-Actuation-as-a-Service. In particular, we focused on describing the subsystem of Stack4Things devoted to resource control and management, highlighting relevant requirements and justifying how our proposed framework addresses them, while also opening up possibilities for a range of future extensions towards complete fulfillment of the Sensing-and-Actuation-as-a-Service vision. {\textcopyright} 2015 IEEE.

}, keywords = {Big Data, Clouds, embedded systems, Infrastructure as a service (IaaS), Infrastructure managements, Internet, Internet of Things, Mediated interaction, OpenStack, Resource control, SAaaS, Sensor and actuators, WAMP, Web Socket}, isbn = {9781467381031}, doi = {10.1109/FiCloud.2015.97}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84959059371\&doi=10.1109\%2fFiCloud.2015.97\&partnerID=40\&md5=e702319ada1b2cdde5d5d2061ec278f7}, author = {Francesco Longo and Dario Bruneo and Salvatore Distefano and Giovanni Merlino and Antonio Puliafito} } @article {Longo2015235, title = {Towards the future internet: The RESERVOIR, VISION cloud, and CloudWave experiences}, journal = {International Journal of High Performance Computing and Networking}, volume = {8}, number = {3}, year = {2015}, note = {cited By 0}, pages = {235-247}, publisher = {Inderscience Enterprises Ltd.}, abstract = {

The future internet is evolving as an internet of services, things and infrastructure, and the European Commission is supporting research projects that are contributing to its evolution. Among the others, RESERVOIR, VISION Cloud and CloudWave are three interesting examples of how infrastructures and data can be managed in an effective way and how applications can adapt to the infrastructure, and the infrastructure to the services requested, in order to improve the overall quality of the service provided. From our experience in these three successful projects, we show in this paper how they try to address the challenges described above, providing an important boost to making the future internet vision concrete. We also discuss our view of the future internet where sensors, actuators and objects are part of the cloud. Copyright {\textcopyright} 2015 Inderscience Enterprises Ltd.

}, keywords = {Adaptation, Clouds, European Commission, Future internet, IaaS, Information management, Internet, Internet of Services, IoT, Overall quality, Sensors}, issn = {17400562}, doi = {10.1504/IJHPCN.2015.071260}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84940376740\&partnerID=40\&md5=8cfa4a88d00a48cee9ec543c43d7a425}, author = {Francesco Longo and Dario Bruneo and Massimo Villari and Antonio Puliafito and Eliot Salant and Yaron Wolfsthal} } @article {Longo20151540, title = {Two-layer symbolic representation for stochastic models with phase-type distributed events}, journal = {International Journal of Systems Science}, volume = {46}, number = {9}, year = {2015}, note = {cited By 2}, pages = {1540-1571}, publisher = {Taylor and Francis Ltd.}, abstract = {

Among the techniques that have been proposed for the analysis of non-Markovian models, the state space expansion approach showed great flexibility in terms of modelling capacities.The principal drawback is the explosion of the state space. This paper proposes a two-layer symbolic method for efficiently storing the expanded reachability graph of a non-Markovian model in the case in which continuous phase-type distributions are associated with the firing times of system events, and different memory policies are considered. At the lower layer, the reachability graph is symbolically represented in the form of a set of Kronecker matrices, while, at the higher layer, all the information needed to correctly manage event memory is stored in a multi-terminal multi-valued decision diagram. Such an information is collected by applying a symbolic algorithm, which is based on a couple of theorems. The efficiency of the proposed approach, in terms of memory occupation and execution time, is shown by applying it to a set of non-Markovian stochastic Petri nets and comparing it with a classical explicit expansion algorithm. Moreover, a comparison with a classical symbolic approach is performed whenever possible. {\textcopyright} 2013 Taylor \& Francis.

}, keywords = {Decision diagram, Decision theory, efficient memory occupation, Many valued logics, Markov processes, Non-Markovian, Petri nets, phase type distributions, Stochastic models, Stochastic systems, symbolic representation}, issn = {00207721}, doi = {10.1080/00207721.2013.822940}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84928644988\&partnerID=40\&md5=3f853e6fcb8bddeebf2e890076ff798d}, author = {Francesco Longo and Marco Scarpa} } @article {Longo20152506, title = {Variable operating conditions in distributed systems: Modeling and evaluation}, journal = {Concurrency Computation Practice and Experience}, volume = {27}, number = {10}, year = {2015}, note = {cited By 1}, pages = {2506-2530}, publisher = {John Wiley and Sons Ltd}, abstract = {

SummaryPerformance and dependability evaluation plays a key role in the design of a broad range of systems, especially when strict requirements need to be met. This is particularly challenging in distributed contexts, where several components may interact among themselves by influencing each other. In this paper, we present an analytical method that allows the study of a class of systems where different operating conditions alternate by changing the stochastic behavior of the system components but still preserving the continuity of the performance and dependability quantities to investigate. The proposed solution technique, based on phase type distributions, Kronecker algebra, and ad-hoc fitting algorithms, can be applied for the analytical evaluation of a wide class of distributed systems. Examples are provided to show the usefulness and the applicability of the methodology, characterizing and investigating different performance and dependability aspects of three distributed computing systems, that is, a connection-oriented network, an Internet of Things application, and an Infrastructure-as-a-Service Cloud. Copyright {\textcopyright} 2014 John Wiley \& Sons, Ltd.

}, keywords = {Algebra, cloud computing, Conservative systems, Dependability, Distributed computer systems, Internet, Internet of Things, Kronecker algebra, Markov processes, Non-Markovian, Performance, phase type distributions, Stochastic systems}, issn = {15320626}, doi = {10.1002/cpe.3419}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84932604392\&partnerID=40\&md5=b8f197a50fa177e85f0c1ac2a93fe392}, author = {Francesco Longo and Dario Bruneo and Salvatore Distefano and Marco Scarpa} } @proceedings {Marquezan201555, title = {3-D cloud monitoring: Enabling effective cloud infrastructure and application management}, journal = {Proceedings of the 10th International Conference on Network and Service Management (CNSM)}, year = {2014}, note = {cited By 0; Conference of 10th International Conference on Network and Service Management, CNSM 2014 ; Conference Date: 17 November 2014 Through 21 November 2014; Conference Code:110192}, pages = {55-63}, publisher = {IEEE Computer Society}, address = {Rio de Janeiro, Brazil, 17-21 November 2014}, abstract = {

A cloud environment is a complex environment composed of many different entities and layers. Each of these cloud entities may be furnished with mechanisms offering various management actions. For any given situation, different management actions may be applicable and often simultaneously. Enforcing isolated management actions or combining contradictory management actions may negatively affect cloud application quality and cloud infrastructure performance. This means that correctly selecting and effectively combining these management actions for a given situation becomes an important challenge in cloud computing. In this paper, we address the problem of identifying situations where more than one management action can be performed. The key contributions of our paper are: (1) a three dimensional (3-D) monitoring model for analyzing cloud monitoring information; (2) the concept and formalization of Context of Interest (CoI) that specifies how to retrieve meaningful information from the 3-D model to support the coordination of management actions between cloud infrastructure and application. We conducted experiments in a real testbed using Openstack and the WordPress Web site application. Our results show that analyzing cloud monitoring information using the 3-D model and the CoI can support a more effective identification of management actions to be taken. {\textcopyright} 2014 IFIP.

}, keywords = {Application management, Cloud applications, Cloud environments, Cloud infrastructures, Complex environments, Complex networks, Formalization of context, Monitoring models, Three dimensional computer graphics, Threedimensional (3-d)}, isbn = {9783901882661}, doi = {10.1109/CNSM.2014.7014141}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84922823116\&partnerID=40\&md5=14afe05eea8a48d4fc7c6c8e57dd6208}, author = {Clarissa Marquezan and Dario Bruneo and Francesco Longo and Florian Wessling and Andreas Metzger and Antonio Puliafito} } @proceedings {Bruneo2014, title = {CloudWave: Where adaptive cloud management meets DevOps}, journal = {Proceedings of the 5th IEEE International Workshop on Performance Evaluation of Communications in Distributed Systems and Web based Service Architectures (PEDISWESA) Co-located with the 19th International Symposium on Computers and Communications (ISCC)}, year = {2014}, note = {cited By 0; Conference of ISCC 2014 Workshop - 5th IEEE International Workshop on Performance Evaluation of Communications in Distributed Systems and Web based Service Architectures, PEDISWESA 2014 ; Conference Date: 23 June 2014 Through 26 June 2014; Conference Code:108095}, publisher = {IEEE Computer Society}, address = {Island of Madeira, Funchal, Portugal, 23-26 June 2014}, abstract = {

The transition to cloud computing offers a large number of benefits, such as lower capital costs and a highly agile environment. Yet, the development of software engineering practices has not kept pace with this change. Moreover, the design and runtime behavior of cloud based services and the underlying cloud infrastructure are largely decoupled from one another.This paper describes the innovative concepts being developed by CloudWave to utilize the principles of DevOps to create an execution analytics cloud infrastructure where, through the use of programmable monitoring and online data abstraction, much more relevant information for the optimization of the ecosystem is obtained. Required optimizations are subsequently negotiated between the applications and the cloud infrastructure to obtain coordinated adaption of the ecosystem. Additionally, the project is developing the technology for a Feedback Driven Development Standard Development Kit which will utilize the data gathered through execution analytics to supply developers with a powerful mechanism to shorten application development cycles. {\textcopyright} 2014 IEEE.

}, keywords = {cloud computing, Cloud managements, Coordinated Adaptation, DevOps}, isbn = {9781479942770}, issn = {15301346}, doi = {10.1109/ISCC.2014.6912638}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84908149098\&partnerID=40\&md5=a0097ef370a848f29a660ea120514a63}, author = {Dario Bruneo and Thomas Fritz and Sharon Keidar-Barner and Philipp Leitner and Francesco Longo and Clarissa Marquezan and Andreas Metzger and Klaus Pohl and Antonio Puliafito and Danny Raz and Andreas Roth and Eliot Salant and Itai Segall and Massimo Villari and Yaron Wolfsthal and Chris Woods} } @proceedings {Longo2014641, title = {From VISION cloud to cloudwave: Towards the future internet and a new generation of services}, journal = {Proceedings of the 2014 International Conference on Intelligent Networking and Collaborative Systems (INCoS)}, year = {2014}, note = {cited By 0; Conference of 6th International Conference on Intelligent Networking and Collaborative Systems, IEEE INCoS 2014 ; Conference Date: 10 September 2014 Through 12 September 2014; Conference Code:111581}, pages = {641-646}, publisher = {IEEE Computer Society}, address = {Salerno, Italy, 10-12 September 2014}, abstract = {

The Future Internet is required to be fast, flexible and ever-responsive to demands from both humans and machines. It is evolving as an Internet of services, things, and infrastructure and the European Commission is supporting research projects that are contributing to its evolution. Among the others, VISION Cloud and Cloudwave are two interesting examples of how data can be managed in an effective way and how applications can adapt to the infrastructure, and the infrastructure to the services requested, in order to improve the overall quality of the service provided. From our experience in these two successful projects, we show in this paper how they try to address the challenges described above, providing an important boost to making the Future Internet vision concrete. {\textcopyright} 2014 IEEE.

}, keywords = {Adaptation, Clouds, European Commission, Future internet, Information management, Internet, Internet of Services, Overall quality}, isbn = {9781479963867}, doi = {10.1109/INCoS.2014.34}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84926512787\&partnerID=40\&md5=013feb21cc75d62fd30508f89e8a99c9}, author = {Francesco Longo and Dario Bruneo and Massimo Villari and Antonio Puliafito and Eliot Salant and Yaron Wolfsthal} } @proceedings {Distefano2014255, title = {Non-Markovian modeling of a BladeCenter chassis midplane}, journal = {Proceedings of the 11th European Workshop on Computer Performance Engineering (EPEW)}, volume = {8721 Lecture Notes in Computer Science}, year = {2014}, note = {cited By 0; Conference of 11th European Workshop on Computer Performance Engineering, EPEW 2014 ; Conference Date: 11 September 2014 Through 12 September 2014; Conference Code:107431}, pages = {255-269}, publisher = {Springer Verlag}, address = {Florence, Italy, 11-12 September 2014}, abstract = {

In distributed contexts such as Cloud computing, the reliability and availability of the provided resources and services have to be assured in order to meet user requirements. At the infrastructure level, this specification is translated into tighter ones on the datacenter hosting physical resources. In this paper, starting from a real case study of the IBM BladeCenter, we provide a technique for the quantitative evaluation of datacenter infrastructure availability. The proposed technique allows one to take into account both aging phenomena and multiple operating conditions. In particular, one subsystem of the BladeCenter, the chassis midplane, is studied. Indeed, based on the stochastic characterization of the midplane reliability through statistic measurements, a model dealing with the non-exponential failure time distribution thus obtained is evaluated to demonstrate the suitability and the effectiveness of the proposed technique. {\textcopyright} 2014 Springer International Publishing.

}, keywords = {Aging phenomena, Chassis, Failure-time distribution, Non-Markovian modeling, Operating condition, Physical resources, Quantitative evaluation, Reliability and availability, Stochastic models, Stochastic systems, User requirements}, isbn = {9783319108841}, issn = {03029743}, doi = {10.1007/978-3-319-10885-8_18}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84906969232\&partnerID=40\&md5=6840d4a28b6ed80a602f4db06c10343b}, author = {Salvatore Distefano and Francesco Longo and Marco Scarpa and Kishor S. Trivedi} } @inbook {520, title = {Performance Analysis for Large IaaS Clouds}, booktitle = {Large Scale and Big Data}, year = {2014}, pages = {557-578}, publisher = {Auerbach Publications 2014}, organization = {Auerbach Publications 2014}, address = {Boca Raton, Florida, U.S.A.}, issn = {978-1-4665-8150-0}, author = {Rahul Ghosh and Francesco Longo and Kishor Trivedi} } @article {Ghosh201457, title = {Scalable analytics for IaaS cloud availability}, journal = {IEEE Transactions on Cloud Computing - IEEE Computer Society}, volume = {2}, number = {1}, year = {2014}, note = {cited By 5}, pages = {57-70}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, abstract = {

In a large Infrastructure-as-a-Service (IaaS) cloud, component failures are quite common. Such failures may lead to occasional system downtime and eventual violation of Service Level Agreements (SLAs) on the cloud service availability. The availability analysis of the underlying infrastructure is useful to the service provider to design a system capable of providing a defined SLA, as well as to evaluate the capabilities of an existing one. This paper presents a scalable, stochastic model-driven approach to quantify the availability of a large-scale IaaS cloud, where failures are typically dealt with through migration of physical machines among three pools: hot (running), warm (turned on, but not ready), and cold (turned off). Since monolithic models do not scale for large systems, we use an interacting Markov chain based approach to demonstrate the reduction in the complexity of analysis and the solution time. The three pools are modeled by interacting sub-models. Dependencies among them are resolved using fixed-point iteration, for which existence of a solution is proved. The analytic-numeric solutions obtained from the proposed approach and from the monolithic model are compared. We show that the errors introduced by interacting sub-models are insignificant and that our approach can handle very large size IaaS clouds. The simulative solution is also considered for the proposed model, and solution time of the methods are compared. {\textcopyright} 2014 IEEE.

}, keywords = {Availability, availability analysis, cloud computing, Downtime, Existence of a solutions, Infrastructure as a service (IaaS), Iterative methods, Lakes, Maintenance, Markov processes, Model driven approach, Numeric solutions, Service level agreement (SLAs), simulation, Stochastic models, Stochastic reward nets, Stochastic systems}, issn = {21687161}, doi = {10.1109/TCC.2014.2310737}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84906976356\&partnerID=40\&md5=a63dc67c92ef7620c8a3b33aca08348b}, author = {Rahul Ghosh and Francesco Longo and Flavio Frattini and Stefano Russo and Kishor S. Trivedi} } @proceedings {Famulari2014, title = {A simple architecture for secure and private data sharing solutions}, journal = {Proceedings of the 19th International Symposium on Computers and Communications (ISCC)}, year = {2014}, note = {cited By 0; Conference of 19th IEEE Symposium on Computers and Communications, ISCC 2014 ; Conference Date: 23 June 2014 Through 26 June 2014; Conference Code:108094}, publisher = {IEEE Computer Society}, address = {Island of Madeira, Funchal, Portugal, 23-26 June 2014}, abstract = {

In recent years, Storage as a Service Cloud gained popularity among both companies and private users. However, security and interoperability issues still have to be adequately faced and solved. In this work, we propose a simple, secure, and privacy-preserving architecture for inter-Cloud data sharing. The proposed solution relies on open standards for both sharing and communication mechanisms, thus ensuring durability, robustness, and compatibility of the approach in the current Internet. {\textcopyright} 2014 IEEE.

}, keywords = {Data Sharing, Interoperability, Private data sharing, security, Storage Clouds}, isbn = {9781479942787}, issn = {15301346}, doi = {10.1109/ISCC.2014.6912518}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84908199088\&partnerID=40\&md5=8e1066f76187a6ea0b2f4239abb3e3f0}, author = {Antonio Famulari and Francesco Longo and Giuseppe Campobello and Thomas Bonald and Marco Scarpa} } @proceedings {Merlino201521, title = {Stack4Things: Integrating IoT with OpenStack in a Smart City context}, journal = {Proceedings of the 2014 International Conference on Smart Computing Workshops (SMARTCOMP Workshops)}, year = {2014}, note = {cited By 1; Conference of 2014 International Conference on Smart Computing Workshops, SMARTCOMP Workshops 2014 ; Conference Date: 5 November 2014; Conference Code:111083}, pages = {21-28}, publisher = {IEEE Computer Society}, address = {Hong Kong, China, 5 November 2014}, abstract = {

As the adoption of embedded systems, mobiles and other smart devices keeps rising, and the scope of their involvement broadens, for instance in the enablement of Smart City-like scenarios, a pressing need emerges to tame such complexity and reuse as much tooling as possible without resorting to vertical ad-hoc solutions, while at the same time taking into account valid options with regards to infrastructure management, and other more advanced functionalities. In this sense, a widely used and competitive framework for Infrastructure as a Service such as OpenStack, with its breadth in terms of feature coverage and expanded scope, looks like fitting the bill. This work thus describes rationale, efforts, and results so far achieved, for an integration of IoT paradigms and resource ecosystems with such a kind of Cloud-oriented environment, by focusing on a Smart City scenario, and featuring data collection and visualization as example use cases of such integration. {\textcopyright} 2014 IEEE.

}, keywords = {AMQP, Ceilometer, CEP, Clouds, CoAP, data visualization, embedded systems, IaaS, Infrastructure as a service (IaaS), Internet of Things, IoT, Meteorological instruments, MOM, OpenStack, REST, smart cities}, isbn = {9781479964475}, doi = {10.1109/SMARTCOMP-W.2014.7046678}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84925651440\&partnerID=40\&md5=d36947c633a2c7b011bffa40aa32db9f}, author = {Giovanni Merlino and Dario Bruneo and Salvatore Distefano and Francesco Longo and Antonio Puliafito} } @article {Ghosh2014667, title = {Stochastic model driven capacity planning for an infrastructure-as-a-service cloud}, journal = {IEEE Transactions on Services Computing - IEEE Computer Society}, volume = {7}, number = {4}, year = {2014}, note = {cited By 1}, pages = {667-680}, publisher = {Institute of Electrical and Electronics Engineers}, abstract = {

From an enterprise perspective, one key motivation to transform the traditional IT management into Cloud is the cost reduction of the hosted services. In an Infrastructure-as-a-Service (IaaS) Cloud, virtual machine (VM) instances share the physical machines (PMs) in the provider{\textquoteright}s data center. With large number of PMs, providers can maintain low cost of service downtime at the expense of higher infrastructure and other operational costs (e.g., power consumption and cooling costs). Hence, determining the optimal PM capacity requirements that minimize the overall cost is of interest. In this paper, we show how a cost analysis and optimization framework can be developed using stochastic availability and performance models of an IaaS Cloud. Specifically, we study two cost minimization problems to address the capacity planning in an IaaS Cloud: 1) what is the optimal number of PMs that minimizes the total cost of ownership for a given downtime requirement set by service level agreements? and, 2) is it more economical to use cheaper but less reliable PMs or to use costlier but more reliable PMs for insuring the same availability characteristics? We use simulated annealing, a well-known stochastic search algorithm, to solve these optimization problems. Results from our analysis show that the optimal solutions are found within reasonable time. {\textcopyright} 2013 IEEE.

}, keywords = {Capacity planning, Capacity requirement, Clouds, Cost benefit analysis, Cost reduction, Downtime, Infrastructure as a service (IaaS), Maintenance, Optimization, Optimization framework, Optimization problems, Service Level Agreements, Simulated annealing, Stochastic models, Stochastic search algorithms, Stochastic systems, Total cost of ownership}, issn = {19391374}, doi = {10.1109/TSC.2013.44}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84919717849\&partnerID=40\&md5=34c70f14a9a3f838562335050a628985}, author = {Rahul Ghosh and Francesco Longo and Ruofan Xia and Vijay K. Naik and Kishor S. Trivedi} } @proceedings {Bruneo201384, title = {Analytical evaluation of resource allocation policies in green IaaS clouds}, journal = {Proceedings of the IEEE 3rd International Conference on Cloud and Green Computing (CGC) Co-located with the IEEE 3rd International Conference on Social Computing and Its Applications (SCA)}, year = {2013}, note = {cited By 1; Conference of 3rd IEEE International Conference on Cloud and Green Computing, CGC 2013, Held Jointly with the 3rd IEEE International Conference on Social Computing and Its Applications, SCA 2013 ; Conference Date: 30 September 2013 Through 2 October 2013; Conference Code:102391}, pages = {84-91}, publisher = {IEEE Computer Society}, address = {Karlsruhe, Germany, 30 September - 2 October 2013}, abstract = {

Cloud systems represent the new ICT frontier where computing utilities are offered in terms of virtual instances, following the so called as-a-service philosophy. Different commercial solutions have been already put in place but several aspects need to be faced in order to provide high-value services able to meet business requirements. In particular, performance evaluation plays a critical role being strictly related to data center optimization and user satisfaction. Moreover, the use of large data centers able to respond to the high service demand has increased the attention to power efficiency, thus calling for green solutions and energy-aware strategies that jointly consider environmental and economical aspects. In order to design powerful strategies able to meet the quality of service requirements still reducing the energy costs, performance analysis frameworks are needed. In this paper, we present an analytical model, based on stochastic reward nets, that is able to easily implement resource allocation strategies in a green infrastructure as-a-service cloud. The model is organized into layers that represent the virtual resource pool and the physical machines. Different allocation algorithms (i.e., scattering, saturation) have been implemented by properly managing the coordination between the model layers. Numerical results are provided that demonstrate the effectiveness of the proposed approach. {\textcopyright} 2013 IEEE.

}, keywords = {Analytical evaluation, cloud computing, Distributed computer systems, Green Computing, Performance analysis, Performance evaluation, Quality of service, Resource allocation, Resource allocation policy, Resource allocation strategies, Service requirements, Stochastic reward nets, Stochastic systems}, isbn = {9780769551142}, doi = {10.1109/CGC.2013.21}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84893329592\&partnerID=40\&md5=369f37efc4aabea38300336d819db864}, author = {Dario Bruneo and Audric Lhoas and Francesco Longo and Antonio Puliafito} } @article {Bruneo2013279, title = {Analytical investigation of availability in a vision cloud storage cluster}, journal = {Scalable Computing - SCPE}, volume = {14}, number = {4}, year = {2013}, note = {cited By 2}, pages = {279-290}, abstract = {

The goal of VISION Cloud, a European Commission funded project, is to design a new scalable and flexible storage cloud architecture able to provide data-intensive storage cloud services. The proposed environment employs a distributed file system on top of a set of storage rich nodes composing a cluster. Several clusters constitute a data center, while multiple geographically distributed data centers form a single storage cloud. In this paper, we focus on a single VISION Cloud storage cluster, providing a stochastic reward net model for an investigation of its availability. The proposed model is a first attempt at obtaining a quantification of the availability level of the cloud storage provided by the VISION Cloud architecture. {\textcopyright} 2013 SCPE.

}, keywords = {Analytical investigations, cloud architectures, Data intensive, Digital storage, Distributed data, Distributed file systems, European Commission, Flexible storage, Stochastic models, Stochastic reward nets}, issn = {18951767}, doi = {10.12694/scpe.v14i4.933}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84893439215\&partnerID=40\&md5=cd97e97b8741a1e968a6bf8e20271ff8}, author = {Dario Bruneo and Francesco Longo and David Hadas and Elliot K. Kolodner} } @proceedings {Bruneo201371, title = {Availability Assessment of a Vision Cloud Storage Cluster}, journal = {European Conference on Service-Oriented and Cloud Computing (ESOCC)}, volume = {393 Communications in Computer and Information Science}, year = {2013}, note = {cited By 0; Conference of European Conference on Service-Oriented and Cloud Computing, ESOCC 2013 ; Conference Date: 11 September 2013 Through 13 September 2013; Conference Code:106555}, pages = {71-82}, publisher = {Springer Verlag}, address = {Malaga, Spain, 11-13 September 2013}, abstract = {

VISION Cloud is a European Commission funded project, whose aim is to design and propose a new architecture for a scalable and flexible cloud environment. The VISION Cloud reference architecture considers a single cloud as composed by multiple distributed data centers each of which can be composed by a great number of storage clusters. On top of the storage rich nodes forming each cluster, a distributed file system is built. In this paper, we provide an stochastic reward net model for a storage cluster in the context of the storage cloud environment proposed by the VISION Cloud project. The proposed model represents a first step in the direction of obtaining a quantification of the availability level reached through the use of the VISION Cloud proposed architecture from a user perspective. {\textcopyright} Springer-Verlag Berlin Heidelberg 2013.

}, keywords = {Architecture, Availability assessment, cloud computing, Cloud environments, Distributed file systems, European Commission, Proposed architectures, Reference architecture, Stochastic models, Stochastic reward nets, Stochastic systems, User perspectives}, isbn = {9783642453632}, issn = {18650929}, doi = {10.1007/978-3-642-45364-9_7}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84904676242\&partnerID=40\&md5=d7510b50bf986e126b22270279202382}, author = {Dario Bruneo and Francesco Longo and David Hadas and Hillel Kolodner} } @proceedings {Distefano201377, title = {Investigating mobile crowdsensing application performance}, journal = {Proceedings of the 3rd ACM International Symposium on Design and Analysis of Intelligent Vehicular Networks and Applications (DIVANet), Co-located with the 16th ACM Int. Conf. on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM)}, year = {2013}, note = {cited By 0; Conference of 3rd ACM Int. Symp. on Design and Analysis of Intelligent Vehicular Networks and Applications, DIVANet 2013, Held in Conjunction with the 16th ACM Int. Conf. on Modeling, Analysis and Simulation of Wireless and Mobile Systems, MSWiM 2013 ; Conference Date: 3 November 2013 Through 8 November 2013; Conference Code:101342}, pages = {77-83}, publisher = {ACM}, address = {Barcelona, Spain, 3-8 November 2013}, abstract = {

Mobile Crowdsensing (MCS) is an emerging distributed paradigm lying at the intersection between the Internet of Things and the volunteer/crowd-based approach. MCS applications are usually deployed on contributing nodes such as smart devices and mobiles, equipped by sensing resources that sample the physical environment and provide the sensed data, once filtered, aggregated and preprocessed, to the MCS application server. The MCS opportunistic approach unlocks new form of pervasive, participatory sensing applications, acquiring interests also in business contexts that call for adequate techniques and tools to drive architects and developers in MCS application design. Aim of this paper is to evaluate the performance of an MCS application though a stochastic model able to stochastically represent the overall MCS environment, thus providing a valid support to MCS application development. The Petri nets formalism is used due to its expressiveness and the capabilities to represent complex, dependent, non-Markovian, phenomena usually characterizing MCS environments. A specific MCS application is then evaluated to demonstrate the effectiveness of the proposed technique on a real case study. {\textcopyright} 2013 ACM.

}, keywords = {Application development, Application performance, Complex networks, crowdsensing, Design, Digital storage, Internet of Things (IOT), Participatory sensing applications, Performance, Petri nets, Physical environments, Stochastic models, Techniques and tools}, isbn = {9781450323581}, doi = {10.1145/2512921.2512931}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84889685098\&partnerID=40\&md5=15df22b992482173437dcd8080bbbc94}, author = {Salvatore Distefano and Francesco Longo and Marco Scarpa} } @article {Ghosh20131216, title = {Modeling and performance analysis of large scale IaaS clouds}, journal = {Future Generation Computer Systems - Elsevier}, volume = {29}, number = {5}, year = {2013}, note = {cited By 10}, pages = {1216-1234}, abstract = {

For Cloud based services to support enterprise class production workloads, Mainframe like predictable performance is essential. However, the scale, complexity, and inherent resource sharing across workloads make the Cloud management for predictable performance difficult. As a first step towards designing Cloud based systems that achieve such performance and realize the service level objectives, we develop a scalable stochastic analytic model for performance quantification of Infrastructure-as-a-Service (IaaS) Cloud. Specifically, we model a class of IaaS Clouds that offer tiered services by configuring physical machines into three pools with different provisioning delay and power consumption characteristics. Performance behaviors in such IaaS Clouds are affected by a large set of parameters, e.g., workload, system characteristics and management policies. Thus, traditional analytic models for such systems tend to be intractable. To overcome this difficulty, we propose a multi-level interacting stochastic sub-models approach where the overall model solution is obtained iteratively over individual sub-model solutions. By comparing with a single-level monolithic model, we show that our approach is scalable, tractable, and yet retains high fidelity. Since the dependencies among the sub-models are resolved via fixed-point iteration, we prove the existence of a solution. Results from our analysis show the impact of workload and system characteristics on two performance measures: mean response delay and job rejection probability. {\textcopyright} 2012 Elsevier B.V. All rights reserved.

}, keywords = {Analytic modeling, Analytical models, Clouds, CTMC, Fixed-point iterations, IaaS, Infrastructure as a service (IaaS), Performance, Provisioning, Stochastic models, Stochastic systems, Submodels}, issn = {0167739X}, doi = {10.1016/j.future.2012.06.005}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84887062784\&partnerID=40\&md5=5aa7bb3aa9d27ba52b585a03501c8e18}, author = {Rahul Ghosh and Francesco Longo and Vijay K. Naik and Kishor S. Trivedi} } @proceedings {Distefano2013385, title = {Quantitative dependability assessment of distributed systems subject to variable conditions}, journal = {6th International Conference on Internet and Distributed Computing Systems (IDCS)}, volume = {8223 Lecture Notes in Computer Science}, year = {2013}, note = {cited By 1; Conference of 6th International Conference on Internet and Distributed Computing Systems, IDCS 2013 ; Conference Date: 28 October 2013 Through 30 October 2013; Conference Code:102547}, pages = {385-398}, publisher = {Springer-Verlag}, address = {Hangzhou, China, 28-30 October 2013}, abstract = {

Dependability evaluation plays a key role in the design of a broad range of systems, where related properties have to be carefully analyzed in order to meet the requirements. This is particularly challenging in distributed contexts, where several entities may interact influencing each other. In this paper, we present an analytical framework that allows the study of a class of phenomena where different working conditions alternate, changing the stochastic behavior of the system. The proposed solution technique, based on phase type distributions and on ad-hoc fitting algorithms, can be applied in dependability evaluation of a wide class of distributed systems. Examples are provided to show the usefulness and the applicability of the framework, characterizing and investigating different dependability aspects of two distributed computing systems, i.e., connection-oriented networks and Internet of Things. {\textcopyright} Springer-Verlag 2013.

}, keywords = {Artificial intelligence, Computer science, Computers, Dependability assessments, Dependability evaluation, Distributed computing systems, Internet, Internet of Things (IOT), phase type distributions, Solution techniques, Stochastic behavior, Variable conditions}, isbn = {9783642414275}, issn = {03029743}, doi = {10.1007/978-3-642-41428-2_31}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84893743730\&partnerID=40\&md5=8ebf6bc7152dd9f2734b969030b62365}, author = {Salvatore Distefano and Dario Bruneo and Francesco Longo and Marco Scarpa} } @proceedings {Bruneo20133, title = {Smart data centers for green clouds}, journal = {Proceedings of the 18th IEEE International Symposium on Computers and Communications (ISCC)}, year = {2013}, note = {cited By 3; Conference of 18th IEEE Symposium on Computers and Communications, ISCC 2013 ; Conference Date: 7 July 2013 Through 10 July 2013; Conference Code:103472}, pages = {3-8}, publisher = {IEEE Computer Society}, address = {Split, Croatia, 7-10 July 2013}, abstract = {

The key idea behind this work is the development of smart data centers able to monitor, control, and manage themselves through advanced analytics and management policies, collecting and analyzing real time data on their behavior. They also make adjustments to interdependent components across the physical infrastructure, in order to address changing business and technology needs. To this aim, we have designed and implemented a new framework for supporting green computing in the management of Cloud data centers. Through heterogeneous sensing devices deployed in the system, the framework is able to know the working state of the data center and to activate specific energy saving policies. We have evaluated the proposed solution through experiments on a real testbed implemented at the University of Messina. Experiments show interesting results thus proving real benefits deriving from the adoption of the proposed framework. {\textcopyright} 2013 IEEE.

}, keywords = {Cloud data centers, Clouds, Data centers, Experiments, Green Computing, Heterogeneous devices, Heterogeneous sensing, Inter-dependent components, Management policy, Physical addresses, sensing, Sensors}, isbn = {9781479937554}, issn = {15301346}, doi = {10.1109/ISCC.2013.6754914}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84897446370\&partnerID=40\&md5=72bf952928d560e009666d68ce6b0fc8}, author = {Dario Bruneo and Maria Fazio and Francesco Longo and Antonio Puliafito} } @article {Bruneo20132090, title = {Stochastic evaluation of QoS in service-based systems}, journal = {IEEE Transactions on Parallel and Distributed Systems - IEEE Computer Society}, volume = {24}, number = {10}, year = {2013}, note = {cited By 7}, pages = {2090-2099}, abstract = {

WS-BPEL language has become the industrial standard to design and orchestrate modular applications, formalizing service compositions and business relationships among providers and consumers. Once service level agreements (SLAs) among the parties are established, effective tools for evaluating appropriate measurements have to be developed to meet the requirements. However, the design of quality of service (QoS)-guaranteed composed Web services (WSes) still requires several efforts. This work aims at proposing a complete method to study the QoS of a composed WS at design time, i.e., when the process is specified by using WS-BPEL. Starting from the nonfunctional properties of the WS to compose, we propose a technique to derive non-Markovian stochastic Petri net (NMSPN) models from WS-BPEL processes, with the final goal of evaluating parameters such as the service time distribution and the service reliability. To demonstrate the effectiveness of the proposed method and to validate the obtained model, a nontrivial example implementing a travel agency flight reservation process, exposed as a synchronous composed WS, is investigated. {\textcopyright} 1990-2012 IEEE.

}, keywords = {Business Process, Business relationships, Design, Information services, Non functional properties, Performance, Quality of service, Random access storage, Reliability, Service level agreement (SLAs), Service oriented architecture (SOA), Service time distribution, Stochastic Petri Nets, Web services, WS-BPEL}, issn = {10459219}, doi = {10.1109/TPDS.2012.313}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84883410035\&partnerID=40\&md5=cdebb3fe5a36e131fd3a9485d01fe3c6}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Marco Scarpa} } @article {519, title = {Vision Cloud: A Cloud Storage Solution Supporting Modern Media Production}, journal = {SMPTE Motion Imaging Journal}, volume = {122}, year = {2013}, pages = {30-37}, issn = {1545-0279}, author = {S. V. Gogouvitis and M. C. Jaeger and H. Kolodner and D. Kyriazis and Francesco Longo and M. Lorenz and A. Messina and M. Montagnuolo and E. Salant and F. Tusa} } @article {Bruneo20131072, title = {Workload-based software rejuvenation in cloud systems}, journal = {IEEE Transactions on Computers - IEEE Computer Society}, volume = {62}, number = {6}, year = {2013}, note = {cited By 21}, pages = {1072-1085}, abstract = {

Cloud computing is a promising paradigm able to rationalize the use of hardware resources by means of virtualization. Virtualization allows to instantiate one or more virtual machines (VMs) on top of a single physical machine managed by a virtual machine monitor (VMM). Similarly to any other software, a VMM experiences aging and failures. Software rejuvenation is a proactive fault management technique that involves terminating an application, cleaning up the system internal state, and restarting it to prevent the occurrence of future failures. In this work, we propose a technique to model and evaluate the VMM aging process and to investigate the optimal rejuvenation policy that maximizes the VMM availability under variable workload conditions. Starting from dynamic reliability theory and adopting symbolic algebraic techniques, we investigate and compare existing time-based VMM rejuvenation policies. We also propose a time-based policy that adapts the rejuvenation timer to the VMM workload condition improving the system availability. The effectiveness of the proposed modeling technique is demonstrated through a numerical example based on a case study taken from the literature. {\textcopyright} 1968-2012 IEEE.

}, keywords = {Algebraic techniques, Application programs, cloud computing, Endocrinology, Kronecker algebra, Numerical methods, phase type distributions, Proactive fault managements, Reliability theory, Software rejuvenation, System availability, Time-based Rejuvenation, Virtual machine monitors, Virtual reality}, issn = {00189340}, doi = {10.1109/TC.2013.30}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84877311601\&partnerID=40\&md5=185051c9b74e6577b5b06c39cbaf7cc7}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Antonio Puliafito and Marco Scarpa} } @inbook {Longo2012134, title = {Availability analysis of IaaS cloud using analytic models}, booktitle = {Achieving Federated and Self-Manageable Cloud Infrastructures: Theory and Practice}, year = {2012}, note = {cited By 0}, pages = {134-157}, publisher = {IGI Global}, organization = {IGI Global}, abstract = {

Cloud based systems are inherently large scale. Failures in such a large distributed environment are quite common phenomena. To reduce the overall Cloud downtime and to provide a seamless service, providers need to assess the availability characteristics of their data centers. Such assessments can be done through controlled experimentations, large scale simulations and via analytic models. In the scale of Cloud, conducting repetitive experimentations or simulations might be costly and time consuming. Analytic models, on the other hand, can be used as a complement to small scale measurements and simulations since the analytic results can be obtained quickly. However, accurate analytic modeling requires dealing with large number of system states, leading to state-space explosion problem. To reduce the complexity of analysis, novel analytic methods are required. This chapter introduces the reader to a novel approach using interacting analytic sub-models and shows how such approach can deal with large scale Cloud availability analysis. The chapter puts the work in perspective of other existing and ongoing research in this area, describe how such approach can be useful to Cloud providers, especially in the case of federated scenarios, and summarize the open research questions that are yet to be solved. {\textcopyright} 2012, IGI Global.

}, isbn = {9781466616318}, doi = {10.4018/978-1-4666-1631-8.ch008}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84898578006\&partnerID=40\&md5=db4db018710246f25dad53c6d32d600d}, author = {Francesco Longo and Rahul Ghosh and Vijay K. Naik and Kishor S. Trivedi} } @article {Bruneo2012521, title = {Evaluating wireless sensor node longevity through Markovian techniques}, journal = {Computer Networks - Elsevier }, volume = {56}, number = {2}, year = {2012}, note = {cited By 13}, pages = {521-532}, abstract = {

Wireless sensor networks are constituted of a large number of tiny sensor nodes randomly distributed over a geographical region. In order to reduce power consumption, nodes undergo active-sleep periods that, on the other hand, limit their ability to send/receive data. The aim of this paper is to analyze the longevity of a battery-powered sensor node. A battery discharge model able to capture both linear and non linear discharge processes is presented. Then, two different models are proposed to investigate the longevity, in terms of reliability, of sensor nodes with active-sleep cycles. The first model, well known in the literature, is based on the Markov reward theory and on the evaluation of the accumulated reward distribution. The second model, based on continuous phase type distributions and Kronecker algebra, represents the main contribution of the present work, since it allows to relax some assumptions of the Markov reward model, thus increasing its applicability to more concrete use cases. In the final part of the paper, the results obtained by applying the two techniques to a case study are compared in order to validate and highlight the benefits of our approach and demonstrate the utility of the proposed model in a quite complex and real scenario. {\textcopyright} 2011 Published by Elsevier B.V.

}, keywords = {Algebra, Battery discharge, Continuous phase, Discharge process, Electric network synthesis, Energy utilization, Kronecker algebra, Markov reward, Markov reward model, Markov reward models, Markovian, Randomly distributed, Reliability, Reliability theory, Sensor nodes, Sensors, Wireless sensor node}, issn = {13891286}, doi = {10.1016/j.comnet.2011.10.003}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84856063119\&partnerID=40\&md5=ecbae538bceec8598d787ee3b936a8e1}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Antonio Puliafito and Marco Scarpa} } @proceedings {Villari2012000820, title = {How a structured testbed enables the rapid development and deployment of cloud services: The VISION Cloud use case}, journal = {Proceedings of the 17th IEEE Symposium on Computers and Communications (ISCC)}, year = {2012}, note = {cited By 0; Conference of 17th IEEE Symposium on Computers and Communication, ISCC 2012 ; Conference Date: 1 July 2012 Through 4 July 2012; Conference Code:92819}, pages = {820-826}, publisher = {IEEE Computer Society}, address = {Cappadocia, Turkey, 1-4 July 2012}, abstract = {

The right setup of a testbed is important for enabling the rapid development and deployment of cloud services, in particular all the times the testbed hosts more concurrent interactions. This work shows how to configure an environment where more developers insist on it. In particular what tools are indispensable for managing compelling distributed cloud environments. We looked at mature Open Source solutions, performing their smoothed integration. The paper describes all parts necessary for accomplishing complex scenarios, even in a bounded perimeter as the VISION Cloud EU project offering. VISION Cloud represents the reference architecture dealing with Cloud Storage, and our work attempts to provide solutions applied on VISION, but suitable for any type of framework. {\textcopyright} 2012 IEEE.

}, keywords = {Advanced Testbed Setup, Agile software development, cloud computing, Cloud services, Concurrent interactions, Distributed database systems, Open-source solutions, Reference architecture, Software engineering, Testbeds, VISION-Cloud, Web services}, isbn = {9781467327121}, issn = {15301346}, doi = {10.1109/ISCC.2012.6249402}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84866596171\&partnerID=40\&md5=98dff4b158cbd130ee2ce510a4bc88fb}, author = {Massimo Villari and Francesco Longo and Maurizio Paone and Francesco Tusa and Michael C. Jaeger} } @article {Distefano20123701, title = {Investigating dynamic reliability and availability through state-space models}, journal = {Computers and Mathematics with Applications - Elsevier Ltd}, volume = {64}, number = {12}, year = {2012}, note = {cited By 7}, pages = {3701-3716}, abstract = {

Quality standards impose increasingly stringent requirements and constraints on quality of service attributes and measures. As a consequence, aspects, phenomena, and behaviors, hitherto approximated or neglected, have to be taken into account in quantitative assessment in order to provide adequate measures satisfying smaller and smaller confidence intervals and tolerances. With specific regards to reliability and availability, this means that interferences and dependencies involving the components of a system can no longer be neglected. Therefore, in order to support such a trend, specific techniques and tools are required to adequately deal with dynamic aspects in reliability and availability assessment. The main goal of this paper is to demonstrate how state-space based techniques can satisfy such a demand. For this purpose some examples of specific dynamic reliability behaviors, such as common cause failure and load sharing, are considered applying state-space based techniques to study the corresponding reliability models. Different repair policies in availability contexts are also explored. Both Markovian and non-Markovian models are studied via phase type expansion and renewal theory in order to adequately represent and evaluate the considered dynamic reliability aspects in case of generally distributed lifetimes and times to repair. {\textcopyright} 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Availability, Common cause failure, Confidence interval, Dynamic aspects, Dynamic reliability, Load sharing, Markov processes, Markov regenerative process, Markovian, Non-Markovian, Quality of service, Quality standard, Quantitative assessments, Reliability, Reliability and availability, Reliability model, Renewal theory, Repair policy, Semi Markov model, State-space, State-space models, Stringent requirement}, issn = {08981221}, doi = {10.1016/j.camwa.2012.02.038}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84870249108\&partnerID=40\&md5=9ecb143c24c7493a16292faa4f50d175}, author = {Salvatore Distefano and Francesco Longo and Kishor S. Trivedi} } @proceedings {Bruneo2012277, title = {Modeling energy-aware cloud federations with SRNs}, journal = {32nd International Conference on Application and Theory of Petri Nets and Concurrency (Petri Nets)}, volume = {7400 Lecture Notes in Computer Science}, year = {2012}, note = {cited By 4; Conference of 32nd International Conference on Application and Theory of Petri Nets and Concurrency, Petri Nets 2011 ; Conference Date: 20 June 2011 Through 24 June 2011; Conference Code:94089}, pages = {277-307}, publisher = {Springer-Verlag}, address = {Newcastle upon Tyne, United Kingdom, 20-24 June 2011}, abstract = {

Cloud computing is a challenging technology that promises to strongly modify the way computing and storage resources will be accessed in the near future. However, it may demand huge amount of energy if adequate management policies are not put in place. In particular, in the context of Infrastructure as a Service (IaaS) Cloud, optimization strategies are needed in order to allocate, migrate, consolidate virtual machines, and manage the switch on/switch off period of a data centre. In this paper, we present a methodology based on stochastic reward nets (SRNs) to investigate the more convenient strategies to manage a federation of two or more private or public IaaS Clouds. Several policies are presented and their impact is evaluated, thus contributing to a rational and efficient adoption of the Cloud computing paradigm. {\textcopyright} 2012 Springer-Verlag.

}, keywords = {cloud computing, Computing paradigm, Data centres, Digital storage, Energy aware, Energy conservation, Management policy, Optimization strategy, Performance evaluation, Petri nets, Quality of service, Stochastic reward nets, Stochastic systems, Storage resources, Switch-on, virtual machines}, isbn = {9783642351785}, issn = {03029743}, doi = {10.1007/978-3-642-35179-2_12}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84870045120\&partnerID=40\&md5=b1e106331e417cc512bcbc713cc582de}, author = {Dario Bruneo and Francesco Longo and Antonio Puliafito} } @proceedings {Bruneo20128, title = {Software rejuvenation in the cloud}, journal = {Proceedings of the 5th International Conference on Simulation Tools and Techniques (SIMUTools)}, year = {2012}, note = {cited By 0; Conference of 5th International Conference on Simulation Tools and Techniques, SIMUTools 2012 ; Conference Date: 19 March 2012 Through 23 March 2012; Conference Code:110134}, pages = {8-16}, publisher = {ICST}, address = {Desenzano del Garda, Italy, 19-23 March 2012}, abstract = {

In this paper, we investigate how software rejuvenation can be used in a Cloud environment to increase the availability of a virtualized system composed of a single virtual machine monitor (VMM) on top of which a certain number of virtual machines (VMs) can be instantiated. We start from the assumption that the aging of a VMM increases with the number of VMs it is managing, thus characterizing the problem in terms of dynamic reliability. Therefore, by identifying the age of the VMM with its reliability and based on the conservation of reliability principle, we characterize the time to failure of the VMM through continuous phase type distributions. The system availability is thus modeled by an expanded continuous time Markov chain expressed in terms of Kronecker algebra in order to face the state space explosion and to keep memory of the age reached by the VMM in case the number of the hosted VMs change. Time-based rejuvenation is taken into consideration and the optimal timer is evaluated in order to maximize the VMM availability. Copyright {\textcopyright} 2012 ICST.

}, keywords = {Availability, cloud computing, Continuous phase type distributions, Continuous time Markov chain, Continuous time systems, Endocrinology, Java programming language, Markov processes, phase type distributions, Rejuvenation, Reliability, Reliability principles, Software rejuvenation, Virtual machine monitors, Virtual reality, Virtualized environment}, isbn = {9781450315104}, doi = {10.4108/icst.simutools.2012.247772}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84922767370\&partnerID=40\&md5=a03b06eec703c94d55c0f4875f181902}, author = {Dario Bruneo and Francesco Longo and Antonio Puliafito and Marco Scarpa and Salvatore Distefano} } @article {80, title = {An Approach For Security, Performance, And Generic Data Retrieval In Reservoir Clouds}, journal = {Journal of Information Assurance and Security - Dynamic Publishers Inc.Dynamic Publishers Inc.}, volume = {6}, year = {2011}, pages = {262{\textendash}272}, issn = {1554-1010}, author = {Antonio Celesti and Massimo Villari and Antonio Puliafito and Francesco Longo} } @proceedings {Bruneo2011, title = {Evaluating energy consumption in a cloud infrastructure}, journal = {2011 IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM)}, year = {2011}, note = {cited By 4; Conference of 2011 IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks, WoWMoM 2011 ; Conference Date: 20 June 2011 Through 23 June 2011; Conference Code:86401}, publisher = {IEEE Computer Society}, address = {Lucca, Italy, 20-23 June 2011}, abstract = {

Cloud computing is a challenging technology that promises to strongly modify the way computing and storage resources will be accessed in the near future. Clouds may demand huge amount of energy if adequate management policies are not put in place. Optimization strategies are needed in order to allocate, migrate, consolidate virtual machines and manage the switch on/switch off period of a data center. In this paper, we present a modeling approach based on Stochastic reward nets to investigate the more convenient strategies to manage a federation of Clouds, having in mind the final goal to reduce the overall energy consumption. Several policies are presented and their impact is evaluated, thus contributing to a rational and efficient adoption of the Cloud computing paradigm. {\textcopyright} 2011 IEEE.

}, keywords = {cloud computing, Clouds, computer systems, Computing paradigm, Data centers, Energy utilization, Management policy, Modeling approach, Multimedia systems, Optimization strategy, Performance evaluation, Quality control, Quality of service, Stochastic reward nets, Stochastic systems, Storage resources, Switch-on, virtual machines, Wireless networks}, isbn = {9781457703515}, doi = {10.1109/WoWMoM.2011.5986479}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-80052709389\&partnerID=40\&md5=9d12783598805d3b668813d0d5b70057}, author = {Dario Bruneo and Francesco Longo and Antonio Puliafito} } @article {Bruneo20111213, title = {Performance analysis of job dissemination techniques in Grid systems}, journal = {Concurrency Computation Practice and Experience - John Wiley \& Sons, Inc.}, volume = {23}, number = {11}, year = {2011}, note = {cited By 2}, pages = {1213-1235}, abstract = {

In the last few years, remarkable efforts have been made to extend the Grid paradigm to commercial solutions. Business-oriented grids call for effective Quality of Service strategies able to adapt to different user requirements and to address Service Level Agreements. Performance analysis and prediction with respect to different load conditions or management policies are required to define such strategies. However, the highly distributed nature of Grid systems and the presence of distinct administrative domains make it difficult to carry out performance estimations. In fact, several parameters are involved and the autonomy of each site could make it complex to set them in a proper way. In this paper, we present a non-Markovian Stochastic Petri Net methodology that allows to conduct performance analysis of Grid systems focusing on aspects related to the Virtual Organization as a whole. In particular, different job allocation techniques can be evaluated with respect to both user and provider points-of-view. The influence of different information update policies on the accuracy of the allocation schemes can also be investigated, highlighting the costs/benefits in terms of job waiting time, service availability, and system utilization. The proposed methodology is designed to be as general as possible and it can be applied to analyze a gLite Grid infrastructure taken as case study. {\textcopyright} 2011 John Wiley \& Sons, Ltd.

}, keywords = {Grid computing, Grid infrastructures, Grid systems, Information updates, Job allocation, Load condition, Management policy, Non-Markovian, Performance analysis, Performance estimation, performance measurements, Petri nets, Quality of service, Random access storage, Service availability, Service Level Agreements, Stochastic Petri Nets, Stochastic systems, System utilization, User requirements, Virtual organization, Waiting-time}, issn = {15320626}, doi = {10.1002/cpe.1697}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79960133545\&partnerID=40\&md5=a557a0ec6dd02249f31a6a0960e2bc92}, author = {Dario Bruneo and Francesco Longo and Marco Scarpa and Antonio Puliafito} } @proceedings {Longo2011335, title = {A scalable availability model for Infrastructure-as-a-Service cloud}, journal = {Proceedings of the 41st IEEE/IFIP International Conference on Dependable Systems and Networks (DSN)}, year = {2011}, note = {cited By 33; Conference of 2011 IEEE/IFIP 41st International Conference on Dependable Systems and Networks, DSN 2011 ; Conference Date: 27 June 2011 Through 30 June 2011; Conference Code:86090}, pages = {335-346}, publisher = {IEEE Computer Society}, address = {Hong Kong, Hong Kong, 27-30 June 2011}, abstract = {

High availability is one of the key characteristics of Infrastructure-as-a- Service (IaaS) cloud. In this paper, we show a scalable method for availability analysis of large scale IaaS cloud using analytic models. To reduce the complexity of analysis and the solution time, we use an interacting Markov chain based approach. The construction and the solution of the Markov chains is facilitated by the use of a high-level Petri net based paradigm known as stochastic reward net (SRN). Overall solution is composed by iteration over individual SRN sub-model solutions. Dependencies among the sub-models are resolved using fixed-point iteration, for which existence of a solution is proved. We compare the solution obtained from the interacting sub-models with a monolithic model and show that errors introduced by decomposition are insignificant. Additionally, we provide closed form solutions of the sub-models and show that our approach can handle very large size IaaS clouds. {\textcopyright} 2011 IEEE.

}, keywords = {Analytic models, availability analysis, Closed form solutions, Fixed-point iterations, High availability, Key characteristics, Large sizes, Markov Chain, Markov model, Markov processes, Petri nets, Scalability, Scalable methods, Solution time, Stochastic reward nets, Submodels}, isbn = {9781424492336}, doi = {10.1109/DSN.2011.5958247}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-80051928903\&partnerID=40\&md5=37f3360476d39837acf5098ca20408c7}, author = {Francesco Longo and Rahul Ghosh and Vijay K. Naik and Kishor S. Trivedi} } @proceedings {Distefano2010265, title = {Availability assessment of HA standby redundant clusters}, journal = {Proceedings of the 29th IEEE Symposium on Reliable Distributed Systems (SRDS)}, year = {2010}, note = {cited By 14; Conference of 29th IEEE Symposium on Reliable Distributed Systems, SRDS 2010 ; Conference Date: 31 October 2010 Through 3 November 2010; Conference Code:82914}, pages = {265-274}, publisher = {IEEE Computer Society}, address = {New Delhi, India, 31 October - 3 November 2010}, abstract = {

Computing systems are becoming the heart of modern technology, implementing critical tasks usually demanded to and implying human interactions. This highlights the problem of dependability in computer science contexts. High availability computing/clusters is a possible solution in such cases, implementing standby redundancy as a tradeoff between dependability and costs. From the engineering perspective, this implies the use of specific techniques and tools for adequately evaluating the reliability/availability of high availability clusters, also taking into account dependencies among nodes (standby, repair, etc.) and the effect of wear and tear into such nodes, especially when failure and repair times are not exponentially distributed. The solution proposed in this paper is based on the use of phase type distributions and Kronecker algebra. In fact, we represent the reliability and maintainability of each component by specific phase type distributions, whose interactions describe the system availability. This latter is thus modeled by an expanded Markov chain expressed in terms of Kronecker algebra in order to face the state space explosion problem of expansion techniques and to represent the memory policies related to the aging process. More specifically, the paper firstly details the technique and then applies it to the evaluation of a standby redundant system representing a high availability cluster taken as example with the aim of demonstrating its effectiveness. Moreover, in order to show the potentiality of the technique, different maintenance strategies are evaluated and therefore compared. {\textcopyright} 2010 IEEE.

}, keywords = {Aging process, Algebra, Availability assessment, Computing system, Critical tasks, Dynamic reliability, Engineering perspective, High availability, High-availability clusters, Human interactions, Kronecker algebra, Maintainability, Maintenance strategies, Markov Chain, Markov processes, Modern technologies, phase type distributions, Possible solutions, Quality assurance, Redundancy, Redundant system, Standby redundancy, State-space explosion, System availability, Wear and tear}, isbn = {9780769542508}, issn = {10609857}, doi = {10.1109/SRDS.2010.37}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78650560407\&partnerID=40\&md5=9666fbfeaaae60d0a7d7ca8f388600e7}, author = {Salvatore Distefano and Francesco Longo and Marco Scarpa} } @proceedings {Bruneo2010, title = {QoS assessment of WS-BPEL processes through non-Markovian stochastic Petri nets}, journal = {Proceedings of the 24th IEEE International Symposium on Parallel and Distributed Processing (IPDPS)}, year = {2010}, note = {cited By 11; Conference of 24th IEEE International Parallel and Distributed Processing Symposium, IPDPS 2010 ; Conference Date: 19 April 2010 Through 23 April 2010; Conference Code:80843}, publisher = {IEEE Computer Society}, address = {Atlanta, GA, United States, 19-23 April 2010}, abstract = {

Service Oriented Architecture (SOA) is the most important and effective software paradigm to design Internet-based services. Using the SOA technology, value-added services can be easily deployed as a combination of existing Web services. In this context, WS-BPEL language has become the SOA industrial standard. To allow services to be composed, business relationships between providers and consumers have to be adequately managed. This implies that a formal definition of Quality of Service (QoS) is agreed and that effective tools for its measurement have to be developed. However, the design ofQoS guaranteed composed Web services still requires several efforts due to the highly distributed nature ofsuch software applications. This work aims at proposing a methodology to evaluate Web service performance at the earliest design phase. We present a novel technique to translate WS-BPEL processes into non-Markovian stochastic Petri nets with the final goal to evaluate parameters such as service time distribution and service reliability. The obtained model can be numerically solved through automatic tools, allowing to investigate the service behavior under different operating conditions and thus helping software engineers to develop QoS-guaranteed software solutions. {\textcopyright} 2010 IEEE.

}, keywords = {Automatic tools, Business relationships, Computer software, Design, Design phase, Distributed parameter networks, Effective tool, Formal definition, Graph theory, Industrial standards, Information services, Internet-based services, Non-Markovian, Novel techniques, Operating condition, Petri nets, Quality of service, Service oriented architecture (SOA), Service reliability, Service time distribution, Software applications, Software engineers, Software paradigm, Software solution, Stochastic Petri Nets, Stochastic systems, Value added service, Web services, WS-BPEL}, isbn = {9781424464432}, doi = {10.1109/IPDPS.2010.5470391}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77954020712\&partnerID=40\&md5=70790f3d893defcf4e9c792d8b58c5da}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Marco Scarpa} } @proceedings {Ghosh2010343, title = {Quantifying resiliency of IaaS cloud}, journal = {Proceedings of the 29th IEEE Symposium on Reliable Distributed Systems (SRDS)}, year = {2010}, note = {cited By 16; Conference of 29th IEEE Symposium on Reliable Distributed Systems, SRDS 2010 ; Conference Date: 31 October 2010 Through 3 November 2010; Conference Code:82914}, pages = {343-347}, publisher = {IEEE Computer Society}, address = {New Delhi, India, 31 October - 3 November 2010}, abstract = {

Cloud based services may experience changes - internal, external, large, small - at any time. Predicting and quantifying the effects on the quality-of-service during and after a change are important in the resiliency assessment of a cloud based service. In this paper, we quantify the resiliency of infrastructure-as-a-service (IaaS) cloud when subject to changes in demand and available capacity. Using a stochastic reward net based model for provisioning and servicing requests in a IaaS cloud, we quantify the resiliency of IaaS cloud w.r.t. two key performance measures - job rejection rate and provisioning response delay. {\textcopyright} 2010 IEEE.

}, keywords = {Available capacity, Infrastructure as a services, Performance measure, Quality of service, Rejection rates, Response delays, Stochastic models, Stochastic reward nets}, isbn = {9780769542508}, issn = {10609857}, doi = {10.1109/SRDS.2010.49}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78650562592\&partnerID=40\&md5=6542308f50d349fc7456919e658e6840}, author = {Rahul Ghosh and Francesco Longo and Vijay K. Naikz and Kishor S. Trivedi} } @proceedings {Bruneo2010, title = {Reliability assessment of wireless sensor nodes with non-linear battery discharge}, journal = {2010 IFIP Wireless Days, WD 2010}, year = {2010}, note = {cited By 8; Conference of 2010 IFIP Wireless Days, WD 2010 ; Conference Date: 20 October 2010 Through 22 October 2010; Conference Code:83354}, publisher = {IEEE Computer Society}, address = {Venice, Italy, 20-22 October 2010}, abstract = {

Wireless sensor networks are constituted of a large number of tiny sensor nodes randomly distributed over a geographical region. In order to reduce power consumption, nodes undergo cycles of active-sleep periods that reduce their ability to send/receive data. Aim of this paper is to analyze the reliability of a battery-powered sensor node with active-sleep cycles considering both linear and non linear discharge processes. The approach used in the evaluation is based on continuous phase type distributions and Kronecker algebra. The technique is thus applied to the evaluation of an example in order to demonstrate its effectiveness. The obtained results strongly encourage future work, figuring out possible application in wider network context with complex topology, redundant nodes, and unreliable links, due to the Kronecher algebra capabilities to manage the state space explosion problem. {\textcopyright} 2010 IEEE.

}, keywords = {Algebra, Battery discharge, Continuous phase, Electric network synthesis, Energy consumption, Energy utilization, Kronecker algebra, Markov reward model, Reliability analysis, sensor networks, Sensor nodes, Telecommunication equipment, Wireless sensor, Wireless sensor networks}, isbn = {9781424492299}, doi = {10.1109/WD.2010.5657711}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78751474054\&partnerID=40\&md5=86f6f2fa864d7e52672ab4e4bd83d78a}, author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Antonio Puliafito and Marco Scarpa} } @proceedings {Distefano201045, title = {Symbolic representation techniques in dynamic reliability evaluation}, journal = {Proceedings of the 12th IEEE International Symposium on High Assurance Systems Engineering (HASE)}, year = {2010}, note = {cited By 9; Conference of 2010 IEEE 12th International Symposium on High Assurance Systems Engineering, HASE 2010 ; Conference Date: 3 November 2010 Through 4 November 2010; Conference Code:83929}, pages = {45-53}, publisher = {IEEE Computer Society}, address = {San Jose, CA, United States, 3-4 November 2010}, abstract = {

The increasing demand of quality presses towards more specific requirements, tighter constraints, and higher standards. It is thus necessary to provide new paradigms, techniques, and tools to adequately model and evaluate complex systems. This paper mainly focuses on reliability aspects, also taking into account dynamic-dependent interactions among components. Starting from the conservation of reliability principle, we characterize the time to failure of the system components through continuous phase type distributions. The system reliability is thus modeled by an expanded Markov chain expressed in terms of Kronecker algebra in order to face the state space explosion and to represent the memory policies related to the aging process. A two-component system is taken as example to demonstrate the effectiveness of the technique and to validate it. {\textcopyright} 2010 IEEE.

}, keywords = {Aging process, Algebra, Complex systems, Continuous phase, Dynamic reliability, Kronecker algebra, Markov Chain, Markov processes, phase type distributions, Quality assurance, Reliability, State-space explosion, symbolic representation, System components, System reliability, Systems engineering, Time to failure, Two component systems}, isbn = {9780769542928}, issn = {15302059}, doi = {10.1109/HASE.2010.28}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79951924261\&partnerID=40\&md5=8ed2be2a9f6a7e9d891ed3fb58789d6f}, author = {Salvatore Distefano and Francesco Longo and Marco Scarpa} } @proceedings {Bruneo2010243, title = {VO-level performance analysis of gLite Grids}, journal = {Proceedings of the 19th IEEE Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises (WETICE)}, year = {2010}, note = {cited By 0; Conference of 19th IEEE International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises, WETICE 2010 ; Conference Date: 28 June 2010 Through 30 June 2010; Conference Code:81490}, pages = {243-248}, publisher = {IEEE Computer Society}, address = {Larissa, Greece, 28-30 June 2010}, abstract = {

Business oriented grids call for effective Quality of Service strategies able to adapt to different user requirements. Performance analyses and predictions with respect to different load conditions or management policies are essential instruments to define such strategies. In this paper, we present a non-Markovian Stochastic Petri Net model that allows to conduct performance analyses of Grid systems focusing on aspects related to the Virtual Organization as a whole. Different job allocation techniques will be evaluated with respect to both user and provider point-of-views. We will also investigate the influence of different information update policies on the accuracy of the allocation schemes, highlighting the costs/benefits in terms of job waiting time, service availability, and system utilization. {\textcopyright} 2010 IEEE.

}, keywords = {Business-oriented, gLite middleware, Graph theory, Grid computing, Grid systems, Information updates, Job allocation, Load condition, Management policy, middleware, Non-Markovian, Performance analysis, performance measurements, Petri nets, Quality of service, Random access storage, Service availability, Stochastic models, Stochastic Petri Nets, Stochastic systems, System utilization, User requirements, Virtual organization, Waiting-time}, isbn = {9780769540634}, issn = {15244547}, doi = {10.1109/WETICE.2010.45}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77955917215\&partnerID=40\&md5=5f89b9d07327325a09d78d1af77f0519}, author = {Dario Bruneo and Francesco Longo and Marco Scarpa and Antonio Puliafito} } @proceedings {Longo200944, title = {Applying symbolic techniques to the representation of non-markovian models with continuous ph distributions}, journal = {Proceedings of the 6th European Performance Engineering Workshop (EPEW)}, volume = {5652 Lecture Notes in Computer Science}, year = {2009}, note = {cited By 12}, pages = {44-58}, publisher = {Springer-Verlag Berlin Heidelberg}, address = {London, United Kingdom, 9-10 July 2009}, doi = {10.1007/978-3-642-02924-0_4}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-69049095039\&partnerID=40\&md5=43f8175008b067c328d542555e9ef500}, author = {Francesco Longo and Marco Scarpa} } @proceedings {Ragusa200953, title = {Experiencing with the cloud over glite}, journal = {Proceedings of the 2009 ICSE Workshop on Software Engineering Challenges of Cloud Computing (CLOUD)}, year = {2009}, note = {cited By 7; Conference of 2009 ICSE Workshop on Software Engineering Challenges of Cloud Computing, CLOUD 2009 ; Conference Date: 23 May 2009 Through 23 May 2009; Conference Code:77503}, pages = {53-60}, publisher = {IEEE Computer Society}, address = {Vancouver, BC, Canada, 23 May 2009}, abstract = {

Market competitiveness puts enormous pressures over companies to be agile in providing their offers and adapt to fast changes. In such context, resource dimensioning is an hard and risky task which may lead companies to un-derprovision their data-center, and therefore be unable to cope with peak loads, or to overprovision it, and notfullfill their ROI. Cloud computing ought to provide such ability. In a previous work, we presented our solution for multi-tier web-based application hosting over a gLite based infrastructure. In this paper, we present a further development of our system towards the Cloud model. A scenario describing our system in action is also discussed. {\textcopyright} 2009 IEEE.

}, keywords = {cloud computing, Cloud models, Competition, Computer science, Computer software, Further development, Multi-tier, Peak load, Resource dimensioning, Web-based applications}, isbn = {9781424437139}, doi = {10.1109/CLOUD.2009.5071533}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70349805168\&partnerID=40\&md5=623b9f32a7f837e0d594e9a3c0685b06}, author = {Carmelo Ragusa and Francesco Longo and Antonio Puliafito} } @proceedings {Ragusa2008113, title = {On the assessment of the s-sicilia infrastructure: A grid-based business system}, journal = {Proceedings of the 5th International Workshop on Grid Economics and Business Models (GECON)}, volume = {5206 Lecture Notes in Computer Science}, year = {2008}, note = {cited By 3}, pages = {113-124}, publisher = {Springer-Verlag Berlin Heidelberg}, address = {Las Palmas de Gran Canaria, Spain, 26 August 2008}, doi = {10.1007/978-3-540-85485-2_9}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-52149083280\&partnerID=40\&md5=051b0de5ad28ec5a3a3996e55e059b67}, author = {Carmelo Ragusa and Francesco Longo and Antonio Puliafito} } @proceedings {326, title = {A grid-based infrastructure for business applications}, journal = {Proceedings of the Symposium {\textquotedblright}GRID Open Days at the University of Palermo{\textquotedblright}}, year = {2008}, pages = {205-211}, address = { Palermo, Italy, 6-7 December 2007}, author = {Carmelo Ragusa and Salvatore Arinisi and Francesco Longo and Antonio Puliafito} }