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See detailCA-DAG: Modeling Communication-Aware Applications for Scheduling in Cloud Computing
Kliazovich, Dzmitry UL; Pecero, Johnatan E.; Tchernykh, Andrei et al

in Journal of Grid Computing (2016), 14(1), 23-39

This paper addresses performance issues of resource allocation in cloud computing. We review requirements of different cloud applications and identify the need of considering communication processes ... [more ▼]

This paper addresses performance issues of resource allocation in cloud computing. We review requirements of different cloud applications and identify the need of considering communication processes explicitly and equally to the computing tasks. Following this observation, we propose a new communication-aware model of cloud computing applications, called CA-DAG. This model is based on Directed Acyclic Graphs that in addition to computing vertices include separate vertices to represent communications. Such a representation allows making separate resource allocation decisions: assigning processors to handle computing jobs, and network resources for information transmissions. The proposed CA-DAG model creates space for optimization of a number of existing solutions to resource allocation and for developing novel scheduling schemes of improved efficiency. [less ▲]

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See detailEnergy-Efficient Computation Offloading for Wearable Devices and Smartphones in Mobile Cloud Computing
Ragona, Claudio; Fiandrino, Claudio UL; Kliazovich, Dzmitry UL et al

in IEEE Global Communications Conference (GLOBECOM), San Diego, CA, USA, 2015 (2015, December)

Wearable devices are becoming increasingly popu- lar and are expected to become essential in our everyday life. De- spite continuous improvement of hardware, the lifetime of mobile devices and their ... [more ▼]

Wearable devices are becoming increasingly popu- lar and are expected to become essential in our everyday life. De- spite continuous improvement of hardware, the lifetime of mobile devices and their capabilities still remain a concern. Small size of batteries of smart watches, glasses, helmets and gloves limits the amount of computing, storage and communication resources. Mobile cloud computing can augment the capabilities of wearable devices by helping to execute some of the computing tasks in the cloud. Such computational offloading helps to preserve battery power at the cost of more intensive communications with the cloud. In this paper, we present a model and comprehensive analysis for computational offloading between wearable devices and clouds in realistic setups. [less ▲]

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See detailDistributed Adaptive VoIP Load Balancing in Hybrid Clouds
Cortés-Mendoza, Jorge Mario; Tchernykh, Andrei; Drozdov, Alexander et al

Scientific Conference (2015, September)

Cloud computing as a powerful economic stimulus widely being adopted by many companies. However, the management of cloud infrastructure is a challenging task. Reliability, security, quality of service ... [more ▼]

Cloud computing as a powerful economic stimulus widely being adopted by many companies. However, the management of cloud infrastructure is a challenging task. Reliability, security, quality of service, and cost-efficiency are important issues in these systems. They require resource optimization at multiple layers of the infrastructure and applications. The complexity of cloud computing systems makes infeasible the optimal resource allocation, especially in presence of uncertainty of very dynamic and unpredictable environment. Hence, load balancing algorithms are a fundamental part of the research in cloud computing. We formulate the problem of load balancing in distributed computer environments and review several algorithms. The goal is to understand the main characteristics of dynamic load balancing algorithms and how they can be adapted for the domain of VoIP computations on hybrid clouds. We conclude by showing how none of these works directly addresses the problem space of the considered problem, but do provide a valuable basis for our work. [less ▲]

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See detailService Level Agreement Assurance in Cloud Computing Data Centers
Ibrahim, Abdallah Ali Zainelabden Abdallah UL

Bachelor/master dissertation (2015)

SaaS is providing cloud applications like all the normal classes of applications of normal computing like the web applications, file applications, email applications, real-time applications, highly ... [more ▼]

SaaS is providing cloud applications like all the normal classes of applications of normal computing like the web applications, file applications, email applications, real-time applications, highly interactive applications, massive data analysis applications, high performance computing applications and mobile cloud applications. Cloud computing uses the internet data centers to host the applications and data storage and also the processing power in the addition to the virtualization. Clouds are a huge stack of easily and usefully virtualized services and resources (Like software, platform and hardware). These resources are used by people all over the world and dynamically configured to accommodate more and more load and scale to a huge number of users. This stack of resources and services is delivered to the customers by a pay-per-use model which verifies that the services provided by the cloud providers are provided by means of service level agreements. In this master thesis, we present an assurance to the service level agreement between the cloud users and the cloud services providers by trying to assess and evaluate the cloud computing data centers services and applications provided to the cloud users. Also we introduce mathematical test models for the web, file, real time and distributed applications. We can use these test models to see the behavior of the applications over a long time. In this master thesis, we classify the cloud applications into 8 different classes of applications and then identify the failures and problems which affect these cloud applications. We classify also all failures types which may occur in cloud data centers like network failures, physical server failures, VM unavailability, individual failures racks and individual component failures. We got the important metrics for each class of applications and developed real scenarios for four classes. Then, we introduce different failures to these scenarios to see what is the impact in the most important metrics of applications. Then, we simulate these scenarios in Network Simulator 2. Finally, we solved and mitigated the failures in simulation by using two failure mitigation techniques. The first one is the virtual machine migration and redundancy. The second technique is the forward error correction. Experimental results acquired over the course of this master's thesis give an assessment and verification of the cloud applications services provided by the cloud provider data centers. And also verify that the cloud data center provider gives their users the best services performance and high QoS, we use this verification to assure SLA response times metric and a good quality and performance of services as mentioned inside the SLA document. This verification will be given to the cloud customers. [less ▲]

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See detailPerformance Metrics for Data Center Communication Systems
Fiandrino, Claudio UL; Kliazovich, Dzmitry UL; Bouvry, Pascal UL et al

in 8th IEEE International Conference on Cloud Computing, New York, USA, 2015 (2015, June)

Cloud computing has become a de facto approach for service provisioning over the Internet. It operates relying on a pool of shared computing resources available on demand and usually hosted in data ... [more ▼]

Cloud computing has become a de facto approach for service provisioning over the Internet. It operates relying on a pool of shared computing resources available on demand and usually hosted in data centers. Assessing performance and energy efficiency of data centers becomes fundamental. Industries use a number of metrics to assess efficiency and energy consumption of cloud computing systems, focusing mainly on the efficiency of IT equipment, cooling and power distribution systems. However, none of the existing metrics is precise enough to distinguish and analyze the performance of data center communication systems from IT equipment. This paper proposes a framework of new metrics able to assess performance and energy efficiency of cloud computing communication systems, processes and protocols. The proposed metrics have been evaluated for the most common data center architectures including fat-tree three-tier, BCube and DCell. [less ▲]

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See detailEnergy efficiency of TCP: An analytical model and its application to reduce energy consumption of the most diffused transport protocol
Usman, Muhammad; Kliazovich, Dzmitry UL; Granelli, Fabrizio et al

in International Journal of Communication Systems (2015)

Energy efficient communications become a challenge for both industries and researchers. Incorporating energy efficiency into the design of network protocols and architectures represents a relevant issue ... [more ▼]

Energy efficient communications become a challenge for both industries and researchers. Incorporating energy efficiency into the design of network protocols and architectures represents a relevant issue in networking research. Currently, very few works address energy efficiency as a fundamental feature of network protocols. This paper benchmarks energy efficiency of TCP to understand the parameters and operational mechanics that determine and contribute to energy consumption. We propose an analytical model with energy consumption to protocol operation cycles and novel optimization techniques for reducing energy consumption of TCP. The evaluation results, obtained from NS2 simulations, demonstrate that even minor modifications of the protocol behavior can bring significant savings of energy. [less ▲]

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See detailHEROS: Energy-Efficient Load Balancing for Heterogeneous Data Centers
Guzek, Mateusz UL; Kliazovich, Dzmitry UL; Bouvry, Pascal UL

in 8th IEEE International Conference on Cloud Computing IEEE CLOUD 2015 (2015)

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See detailEnergy Consumption Optimization in Cloud Data Centers
Kliazovich, Dzmitry UL; Bouvry, Pascal UL; Granelli, Fabrizio et al

in Cloud Services, Networking and Management (2015)

Cloud computing data centers are becoming increasingly popular for providing computing resources. However, the expenses of these data centers has skyrocketed with the increase in computing capacity with ... [more ▼]

Cloud computing data centers are becoming increasingly popular for providing computing resources. However, the expenses of these data centers has skyrocketed with the increase in computing capacity with large percentage of the operational expenses due to energy consumption, especially in data centers that are used as backend computing infrastructure for cloud computing. This chapter emphasizes the role of the communication fabric in energy consumption and presents solutions for energy efficient network aware resource allocation in clouds. [less ▲]

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See detailAnalysis of an Energy-Efficient MAC Protocol Based on Polling for IEEE 802.11 WLAN
Palacios, Raul; Mekonnen, Gedlu; Alonso-Zarate, Jesus et al

in IEEE International Conference on Communications (ICC), London, UK, June 2015 (2015)

This paper analyzes the performance of a duty-cycled polling-based access mechanism that exploits the Transmission Opportunity Power Save Mode (TXOP PSM) defined in the IEEE 802.11ac to improve the energy ... [more ▼]

This paper analyzes the performance of a duty-cycled polling-based access mechanism that exploits the Transmission Opportunity Power Save Mode (TXOP PSM) defined in the IEEE 802.11ac to improve the energy efficiency of Wireless Local Area Networks (WLANs) based on the IEEE 802.11. The basic idea behind the proposed approach, named GreenPoll, is to enable contention free periods, based on polling with beacons, during which wireless stations can save energy by turning off their radio transceivers after exchanging data with the access point. The closed expression of energy efficiency of GreenPoll is formulated in this paper and is used to evaluate the performance of GreenPoll considering important parameters like the traffic load, packet length, data rate, and number of stations in the network. Both analytical and simulation results show the high energy efficiency of GreenPoll with gains of up to 330% and 110% when compared to the legacy Distributed Coordination Function (DCF) and the Point Coordination Function (PCF) defined in the IEEE 802.11, respectively. [less ▲]

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See detailModels for Efficient Data Replication in Cloud Computing Datacenters
Boru, Dejene; Kliazovich, Dzmitry UL; Granelli, Fabrizio et al

in IEEE International Conference on Communications (ICC), London, UK, 2015 (2015)

Cloud computing is a computing model where users access ICT services and resources without regard to where the services are hosted. Communication resources often become a bottleneck in service ... [more ▼]

Cloud computing is a computing model where users access ICT services and resources without regard to where the services are hosted. Communication resources often become a bottleneck in service provisioning for many cloud applications. Therefore, data replication which brings data (e.g., databases) closer to data consumers (e.g., cloud applications) is seen as a promising solution. In this paper we present models for energy consumption and bandwidth demand of database access in cloud computing datacenter. In addition we propose an energy efficient replication strategy based on the proposed models which results in improved Quality of Service (QoS) with reduced communication delays. The evaluation results obtained with extensive simulations help to unveil performance and energy efficiency tradeoffs as well as guide the design of future data replication solutions. [less ▲]

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See detailEnergy-efficient Data Replication in Cloud Computing Datacenters
Boru, Dejene; Kliazovich, Dzmitry UL; Granelli, Fabrizio et al

in Cluster Computing (2015), 18(1), 385-402

Cloud computing is an emerging paradigm that provides computing, communication and storage resources as a service over a network. Communication resources often become a bottleneck in service provisioning ... [more ▼]

Cloud computing is an emerging paradigm that provides computing, communication and storage resources as a service over a network. Communication resources often become a bottleneck in service provisioning for many cloud applications. Therefore, data replication which brings data (e.g., databases) closer to data consumers (e.g., cloud applications) is seen as a promising solution. It allows minimizing network delays and bandwidth usage. In this paper we study data replication in cloud computing data centers. Unlike other approaches available in the literature, we consider both energy efficiency and bandwidth consumption of the system. This is in addition to the improved quality of service QoS obtained as a result of the reduced communication delays. The evaluation results, obtained from both mathematical model and extensive simulations, help to unveil performance and energy efficiency tradeoffs as well as guide the design of future data replication solutions. [less ▲]

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See detailNetwork-Assisted Offloading for Mobile Cloud Applications
Fiandrino, Claudio UL; Kliazovich, Dzmitry UL; Bouvry, Pascal UL et al

in IEEE International Conference on Communications (ICC), London, UK, 2015 (2015)

Data traffic from mobile devices experiences unprecedented growth that current cellular network capacities cannot sustain. Traffic offloading to other type of networks such as WiFi emerged as a valid ... [more ▼]

Data traffic from mobile devices experiences unprecedented growth that current cellular network capacities cannot sustain. Traffic offloading to other type of networks such as WiFi emerged as a valid solution to relieve the load in cellular networks. In this paper, we propose novel solution, which unlike other existing methodologies uses information provided by the cellular network to optimize traffic offloading. The provided information includes channel usage statistics, user mobility patterns, information about available resources and other parameters. The offloading decisions aim at optimizing the balance between user and application requirements with availability of network resources. We validated the effectiveness of the proposed solution through simulations with NS-3 network simulator. The results show the capability of the solution in relieving cellular load while guaranteeing user QoS. [less ▲]

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See detailPerformance and Energy Efficiency Metrics for Communication Systems of Cloud Computing Data Centers
Fiandrino, Claudio UL; Kliazovich, Dzmitry UL; Bouvry, Pascal UL et al

in IEEE Transactions on Cloud Computing (2015)

Cloud computing has become a de facto approach for service provisioning over the Internet. It operates relying on a pool of shared computing resources available on demand and usually hosted in data ... [more ▼]

Cloud computing has become a de facto approach for service provisioning over the Internet. It operates relying on a pool of shared computing resources available on demand and usually hosted in data centers. Assessing performance and energy efficiency of data centers becomes fundamental. Industries use a number of metrics to assess efficiency and energy consumption of cloud computing systems, focusing mainly on the efficiency of IT equipment, cooling and power distribution systems. However, none of the existing metrics is precise enough to distinguish and analyze the performance of data center communication systems from IT equipment. This paper proposes a framework of new metrics able to assess performance and energy efficiency of cloud computing communication systems, processes and protocols. The proposed metrics have been evaluated for the most common data center architectures including fat tree three-tier, BCube, DCell and Hypercube. [less ▲]

Detailed reference viewed: 156 (24 UL)
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See detailReverse Direction Transmissions and Network Coding for Energy-Efficient Wi-Fi Networks
Palacios, Raul; Kliazovich, Dzmitry UL; Granelli, Fabrizio

in IEEE International Workshop on Computer-Aided Modeling Analysis and Design of Communication Links and Networks (CAMAD), Athens, Greece, 2014. (2014)

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See detailA Power Efficient Genetic Algorithm for Resource Allocation in Cloud Computing Data Centers
Portaluri, Giuseppe; Giordano, Stefano; Kliazovich, Dzmitry UL et al

in IEEE International Conference on Cloud Networking (CLOUDNET), Luxembourg City, 2014. (2014)

Detailed reference viewed: 71 (1 UL)
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See detailTowards Cognitive Internet: an Evolutionary Vision
Granelli, Fabrizio; Kliazovich, Dzmitry UL; Malheiros, Neumar

in Cognitive Radio and Networking for Heterogeneous Wireless Networks (2014)

Detailed reference viewed: 26 (1 UL)
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See detailProfiling Cloud Applications with Hardware Performance Counters
Kandalintsev, Alexandre; Lo Cigno, Renato; Kliazovich, Dzmitry UL et al

in International Conference on Information Networking (ICOIN), Phuket, Thailand, 2014 (2014)

Detailed reference viewed: 98 (8 UL)
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See detailAdaptive Energy Efficient Distributed VoIP Load Balancing in Federated Cloud Infrastructure
Tchernykh, Andrei; Cortés-Mendoza, Jorge M.; Pecero, Johnatan E. et al

in IEEE International Conference on Cloud Networking (CLOUDNET), Luxembourg City, 2014. (2014)

Detailed reference viewed: 53 (5 UL)
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See detailCloudNetSim++: A Toolkit for Data Center Simulations in OMNET++
Malik, Asad W.; Bilal, Kashif; Aziz, Khurram et al

in 11th IEEE International Symposium on High Capacity Optical Networks and Enabling Technologies (HONET), Charlotte, NC, USA, December 2014. (2014)

With the availability of low cost, on demand, and pay as-you-go model based utility computing services offered by clouds, multiple businesses consider moving their services to the cloud. Typically, the ... [more ▼]

With the availability of low cost, on demand, and pay as-you-go model based utility computing services offered by clouds, multiple businesses consider moving their services to the cloud. Typically, the clouds comprise of geographically distributed data centers connected through a high speed network. Most of the research and development is focused on cloud services, applications, and security issues; however, very limited effort has been devoted to address energy efficiency, scalability, and highspeed inter and intra-data center communication. We present CloudNetSim++, a modeling and simulation toolkit to facilitate simulation of distributed data center architectures, energy models, and high speed data centers' communication network. The CloudNetSim++ is designed to allow researchers to incorporate their custom protocols and, applications, to analyze under realistic data center architectures with network traffic patterns. CloudNetSim++ is the first cloud computing simulator that uses real network physical characteristics to model distributed data centers. CloudNetSim++ provides a generic framework that allows users to define SLA policy, scheduling algorithms, and modules for different components of data centers without worrying about low level details with ease and minimum effort. [less ▲]

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See detailNC-CELL: Network Coding-based Content Distribution in Cellular Networks for Cloud Applications
Fiandrino, Claudio UL; Kliazovich, Dzmitry UL; Bouvry, Pascal UL et al

in IEEE Global Communications Conference, Austin, TX, USA, 2014 (2014)

The popularity of cloud applications surged in the last years. Billions of mobile devices remain always connected. Location services, online games, social networking and navigation are a just few examples ... [more ▼]

The popularity of cloud applications surged in the last years. Billions of mobile devices remain always connected. Location services, online games, social networking and navigation are a just few examples of “always on” cloud applications in which the same or partially overlapping content is delivered to multiple users. In this paper, we propose a technique, called NCCELL, which uses network coding to foster content distribution in mobile cellular networks. Specifically, NC-CELL implements a software module at mobile base stations (or eNodeBs) which cans in transit traffic and looks for opportunities to code packets destined to different mobile users together. The proposed approach can significantly improve cell throughput and is particularly relevant for delay tolerant content distribution. [less ▲]

Detailed reference viewed: 145 (34 UL)