On Reliability-Aware Server Consolidation in Cloud Datacenters

In the past few years, datacenter (DC) energy consumption has become an important issue in technology world. Server consolidation using virtualization and virtual machine (VM) live migration allows cloud DCs to improve resource utilization and hence energy efficiency. In order to save energy, consolidation techniques try to turn off the idle servers, while because of workload fluctuations, these offline servers should be turned on to support the increased resource demands. These repeated on-off cycles could affect the hardware reliability and wear-and-tear of servers and as a result, increase the maintenance and replacement costs. In this paper we propose a holistic mathematical model for reliability-aware server consolidation with the objective of minimizing total DC costs including energy and reliability costs. In fact, we try to minimize the number of active PMs and racks, in a reliability-aware manner. We formulate the problem as a Mixed Integer Linear Programming (MILP) model which is in form of NP-complete. Finally, we evaluate the performance of our approach in different scenarios using extensive numerical MATLAB simulations.Comment: International Symposium on Parallel and Distributed Computing (ISPDC), Innsbruck, Austria, 201

Power Modeling and Resource Optimization in Virtualized Environments

The provisioning of on-demand cloud services has revolutionized the IT industry. This emerging paradigm has drastically increased the growth of data centers (DCs) worldwide. Consequently, this rising number of DCs is contributing to a large amount of world total power consumption. This has directed the attention of researchers and service providers to investigate a power-aware solution for the deployment and management of these systems and networks. However, these solutions could be bene\ufb01cial only if derived from a precisely estimated power consumption at run-time. Accuracy in power estimation is a challenge in virtualized environments due to the lack of certainty of actual resources consumed by virtualized entities and of their impact on applications\u2019 performance. The heterogeneous cloud, composed of multi-tenancy architecture, has also raised several management challenges for both service providers and their clients. Task scheduling and resource allocation in such a system are considered as an NP-hard problem. The inappropriate allocation of resources causes the under-utilization of servers, hence reducing throughput and energy e\ufb03ciency. In this context, the cloud framework needs an e\ufb00ective management solution to maximize the use of available resources and capacity, and also to reduce the impact of their carbon footprint on the environment with reduced power consumption. This thesis addresses the issues of power measurement and resource utilization in virtualized environments as two primary objectives. At \ufb01rst, a survey on prior work of server power modeling and methods in virtualization architectures is carried out. This helps investigate the key challenges that elude the precision of power estimation when dealing with virtualized entities. A di\ufb00erent systematic approach is then presented to improve the prediction accuracy in these networks, considering the resource abstraction at di\ufb00erent architectural levels. Resource usage monitoring at the host and guest helps in identifying the di\ufb00erence in performance between the two. Using virtual Performance Monitoring Counters (vPMCs) at a guest level provides detailed information that helps in improving the prediction accuracy and can be further used for resource optimization, consolidation and load balancing. Later, the research also targets the critical issue of optimal resource utilization in cloud computing. This study seeks a generic, robust but simple approach to deal with resource allocation in cloud computing and networking. The inappropriate scheduling in the cloud causes under- and over- utilization of resources which in turn increases the power consumption and also degrades the system performance. This work \ufb01rst addresses some of the major challenges related to task scheduling in heterogeneous systems. After a critical analysis of existing approaches, this thesis presents a rather simple scheduling scheme based on the combination of heuristic solutions. Improved resource utilization with reduced processing time can be achieved using the proposed energy-e\ufb03cient scheduling algorithm

Scheduling and efficient energy utilization in cloud system

Cloud computing is an emerging topic on software and distributed computing based on Internet, which means users can access storages and applications from remote servers by web browsers or other fixed or mobile terminals. In a cloud framework different services such as servers, storage in the form of data as well as Big data, resources etc are given to a management's computers and different devices on interest through the Internet. Multiple clients want to run their jobs or cloudlets in the cloud at a particular instant of time. The tasks are executed depending on the number of processors available and the scheduling policy of the cloud. In a cloud simulation software such as CloudSim a two level scheduling in the form of Space-shared and Time-shared can be used in collaboration with First Come First Serve(FCFS). An efficient way of job scheduling in cloud is to assign weightage or priority to the various parameters coming along with the job also taking into consideration the priority value set by the client to the task. In this thesis an attempt has been made to develop an efficient priority algorithm for the jobs running in the cloud. Also an attempt has been made to reduce the energy consumption at a particular over utilized node as well as switching idle nodes to the sleep mode thereby optimizing resource usage and reducing energy consumption

Enforcing CPU allocation in a heterogeneous IaaS

International audienceIn an Infrastructure as a Service (IaaS), the amount of resources allocated to a virtual machine (VM) at creation time may be expressed with relative values (relative to the hardware, i.e., a fraction of the capacity of a device) or absolute values (i.e., a performance metric which is independent from the capacity of the hardware). Surprisingly, disk or network resource allocations are expressed with absolute values (bandwidth), but CPU resource allocations are expressed with relative values (a percentage of a processor). The major problem with CPU relative value allocations is that it depends on the capacity of the CPU, which may vary due to different factors (server heterogeneity in a cluster, Dynamic Voltage Frequency Scaling (DVFS)). In this paper, we analyze the side effects and drawbacks of relative allocations. We claim that CPU allocation should be expressed with absolute values. We propose such a CPU resource management system and we demonstrate and evaluate its benefits

Efficient Energy Management in Cloud Data center using VM Consolidation

Cloud computing is a model which can fast provisioned and released the computing resources by using minimum number of management effort. This can be done by the user without doing any communication with the cloud service providers. Cloud provide the computing resources, on-demand network access which is pooled together and it can be provisioned dynamically according to the user needs. Due to the large application, more number of computing nodes are required. A large amount of electrical energy is consumed due to the establishment of the data center. There is a problem of carbon dioxide emissions and increasing cost of operation due to the formation of large data center. A consolidation of virtual machines technique is proposed in our thesis to reduce the energy consumption and to maximize the utilization of the computing resources in the data center. Several virtual machines are taken together into a single physical machine in the consolidation technique and it helps to decrease the consumption of energy by putting idle server into inactive mode. A number of active hosts is minimized by continuously reallocating VMs using live migration. In each migration, Service Level Agreement(SLA) violations may occur, hence it is required to reduce the number of migrations.In order to satisfy quality of services in cloud computing environment, our proposed techniques mainly performs the following functions:(i)reducing the consumption of energy, (ii) minimize the number of migrations and (iii) minimize the percentage of SLA violations. Initially we detect whether any host is overloaded or not. The Overloaded host is detected by considering CPU utilization as a threshold Value. If an overloaded host is detected then some virtual machines are migrated from it by using VM selection policy. After selection of the VMs, the next step is to place the new VMs. For VM placement, the greedy algorithms such as Best Fit Decreasing(BFD) and Modified First Fit Decreasing(MFFD) are used in this thesis. The proposed techniques are compared with the existing EEDVM and PALVM techniques. Using proposed AUTREC technique there is 8% improved in energy consumption, 3% in number of migrations, 10% in SLA violation and 12% in host shutdown as compared to EEDVM technique. Using proposed DUTREC technique there is 9% improved in energy consumption, 6% in number of migrations, 20% in SLA violation and 13% in host shutdown as compared to PALVM technique

EPOBF: Energy Efficient Allocation of Virtual Machines in High Performance Computing Cloud

Cloud computing has become more popular in provision of computing resources under virtual machine (VM) abstraction for high performance computing (HPC) users to run their applications. A HPC cloud is such cloud computing environment. One of challenges of energy efficient resource allocation for VMs in HPC cloud is tradeoff between minimizing total energy consumption of physical machines (PMs) and satisfying Quality of Service (e.g. performance). On one hand, cloud providers want to maximize their profit by reducing the power cost (e.g. using the smallest number of running PMs). On the other hand, cloud customers (users) want highest performance for their applications. In this paper, we focus on the scenario that scheduler does not know global information about user jobs and user applications in the future. Users will request shortterm resources at fixed start times and non interrupted durations. We then propose a new allocation heuristic (named Energy-aware and Performance per watt oriented Bestfit (EPOBF)) that uses metric of performance per watt to choose which most energy-efficient PM for mapping each VM (e.g. maximum of MIPS per Watt). Using information from Feitelson's Parallel Workload Archive to model HPC jobs, we compare the proposed EPOBF to state of the art heuristics on heterogeneous PMs (each PM has multicore CPU). Simulations show that the EPOBF can reduce significant total energy consumption in comparison with state of the art allocation heuristics.Comment: 10 pages, in Procedings of International Conference on Advanced Computing and Applications, Journal of Science and Technology, Vietnamese Academy of Science and Technology, ISSN 0866-708X, Vol. 51, No. 4B, 201

Dynamic Virtual Machine Migration using Network Aware Topology

Clients of the applications communicate with the services hosted in the VMs. Many applications have clients all over the world. An application is expected to provide faster access and transmission of data to its clients if it is geographically close to its clients, as some of the research work suggests that geographical distance has impact on quality of service (QoS) [1,2,3]. In order to provide a faster access and data transfer, applications which have clients all over the world should be hosted in a data center, which is on average close to its clients geographically