Simulating Communication Processes in Energy-Efficient Cloud Computing Systems

in CLOUDNET (2012)

Cloud computing data centers are becoming increasingly popular for the provisioning of computing resources. The cost and operating expenses of data centers have skyrocketed with the increase in computing ... [more ▼]

Cloud computing data centers are becoming increasingly popular for the provisioning of computing resources. The cost and operating expenses of data centers have skyrocketed with the increase in computing capacity. In this chapter, we survey the main techniques behind enabling energy efficiency in data centers and present simulation environment for energy-aware cloud computing. Along with the workload distribution, the focus is devoted to simulating packet-level communications in realistic setups. Finally, the effectiveness of common power management solutions is assessed and a scheduling methodology that combines energy efficiency and network awareness is presented. [less ▲]

Satellite Payload Reconfiguration Optimisation: An ILP Model

in Proceedings of the 4th Asian Conference on Intelligent Information and Database Systems (ACIIDS'12) (2012)

Optimisation of the enhanced distance based broadcasting protocol for MANETs

in Journal of Supercomputing (2012), 62(3), 1213-1240

Impact of Voltage Levels Number for Energy-aware Bi-objective DAG Scheduling for Multi-processors Systems

in Advances in Information Technology: 5th International Conference, IAIT 2012, Bangkok, Thailand, December 6-7, 2012, Proceedings (2012)

A two-phase heuristic for the energy-efficient scheduling of independent tasks on computational grids

in Cluster Computing (2012)

Security and Intelligent Information Systems

Book published by Springer (2012)

Designing a Self-organized Approach for Scheduling Bag-of-Tasks

in Designing a Self-organized Approach for Scheduling Bag-of-Tasks (2012)

This paper proposes a decentralized and self-organized agent system for dynamically load-balancing tasks arriving in the form of Bags-of-Tasks (BoTs) in large-scale decentralized systems. The approach is ... [more ▼]

This paper proposes a decentralized and self-organized agent system for dynamically load-balancing tasks arriving in the form of Bags-of-Tasks (BoTs) in large-scale decentralized systems. The approach is inspired by the emergent behavior of the sandpile model; a cellular automaton behaving at the edge of chaos. Depending on the state of the cellular automaton, rather different responses may occur when a new task is assigned to a resource. It may change nothing or generate avalanches that reconfigure the state of the system. The proportion between the abundance of avalanches and their sizes shows a power-law relation, a scale-invariant behavior that does not need to be tuned. That means that large –catastrophic– avalanches are very rare but small ones occur very often. Such a smart and emergent behavior fits well with the idea of non-clairvoyant scheduling, where tasks are load balanced into computing resources trying to maximize the performance but without assuming any knowledge on the tasks features. In order to study the viability of the approach, we have conducted an empirical experimentation which shows that the sandpile is able to find near-optimal schedules by reacting differently to different conditions of workloads and architectures. [less ▲]

A Multi-objective GRASP Algorithm for Joint Optimization of Energy Consumption and Schedule Length of Precedence-Constrained Applications

in 2011 IEEE Ninth International Conference on Dependable, Autonomic and Secure Computing (DASC) (2011, December 14)

We address the problem of scheduling precedence-constrained scientific applications on a heterogeneous distributed processor system with the twin objectives of minimizing simultaneously energy consumption ... [more ▼]

We address the problem of scheduling precedence-constrained scientific applications on a heterogeneous distributed processor system with the twin objectives of minimizing simultaneously energy consumption and schedule length. Previous research efforts on scheduling have focused on the minimization of a quality of service metric based on the completion time of applications (e.g., the schedule length). Recently, many researchers are working on the design of new scheduling algorithms that consider the minimization of energy consumption. We report a new scheduling algorithm accounting for both objectives. The new scheduling algorithm is based on a multi-start randomized adaptive search technique (GRASP framework) that adopts Dynamic Voltage Scaling technique to minimize energy consumption. This technique enables processors to operate in different voltage supply levels at the cost of sacrificing clock frequencies. This multiple voltage implies a trade-off between the quality of the schedules and energy consumption. Therefore, the new proposed approach is designed as a multi-objective algorithm that simultaneously optimize both objectives. Simulation results on a set of real-world applications emphasize the robust performance of the proposed approach. [less ▲]

CertiCloud: a Novel TPM-based Approach to Ensure Cloud IaaS Security

in 4th IEEE Intl. Conf. on Cloud Computing (CLOUD 2011) (2011, July)

The security issues raised by the Cloud paradigm are not always tackled from the user point of view. For instance, considering an Infrastructure-as-a-Service (IaaS) Cloud, it is currently impossible for a ... [more ▼]

The security issues raised by the Cloud paradigm are not always tackled from the user point of view. For instance, considering an Infrastructure-as-a-Service (IaaS) Cloud, it is currently impossible for a user to certify in a reliable and secure way that the environment he deployed (typically a Virtual Machine(VM)) has not been corrupted, whether by malicious acts or not. Yet having this functionality would enhance the confidence on the IaaS provider and therefore attract new customers. This paper fills this need by proposing CERTICLOUD, a novel approach for the protection of IaaS platforms that relies on the concepts developed in the Trusted Computing Group (TCG) together with hardware elements, i.e., Trusted Platform Module (TPM) to offer a secured and reassuring environment. Those aspects are guaranteed by two protocols: TCRR and Verify MyVM. When the first one asserts the integrity of a remote resource and permits to exchange a private symmetric key, the second authorizes the user to detect trustfully and on demand any tampering attempt on its running VM. These protocols being key components in the proposed framework, we take very seriously their analysis against known cryptanalytic attacks. This is testified by their successful validation by AVISPA and Scyther, two reference tools for the automatic verification of security protocols. The CERTICLOUD proposal is then detailed: relying on the above protocols, this platform provides the secure storage of users environments and their safe deployment onto a virtualization framework. While the physical resources are checked by TCRR, the user can execute on demand the Verify MyVM protocol to certify the integrity of its deployed environment. Experimental results operated on a first prototype of CERTICLOUD demonstrate the feasibility and the low overhead of the approach, together with its easy implementation on recent commodity machines. [less ▲]

A Model for Energy-efficient Task Mapping on Milliclusters

in Proceedings of the Second International Conference on Parallel, Distributed, Grid and Cloud Computing for Engineering (2011)

This paper exposes the mismatch between the classic problem representation in the scheduling problem of independent task mapping and the reality of multi-core proces- sors, operating system driven power ... [more ▼]

This paper exposes the mismatch between the classic problem representation in the scheduling problem of independent task mapping and the reality of multi-core proces- sors, operating system driven power management and time sharing for overlapping I/O with computation. A new, simple, model is proposed to address this gap. The model, along with a scheduling heuristic, are applied to the evaluation of software pipelin- ing in the context of the recent millicomputing initiative. [less ▲]