Service-level agreement

About: Service-level agreement is a research topic. Over the lifetime, 4358 publications have been published within this topic receiving 75333 citations. The topic is also known as: SLA.

Utilization Prediction Aware VM Consolidation Approach for Green Cloud Computing

Abstract: Dynamic Virtual Machine (VM) consolidation is one of the most promising solutions to reduce energy consumption and improve resource utilization in data centers. Since VM consolidation problem is strictly NP-hard, many heuristic algorithms have been proposed to tackle the problem. However, most of the existing works deal only with minimizing the number of hosts based on their current resource utilization and these works do not explore the future resource requirements. Therefore, unnecessary VM migrations are generated and the rate of Service Level Agreement (SLA) violations are increased in data centers. To address this problem, our VM consolidation method which is formulated as a bin-packing problem considers both the current and future utilization of resources. The future utilization of resources is accurately predicted using a k-nearest neighbor regression based model. In this paper, we investigate the effectiveness of VM and host resource utilization predictions in the VM consolidation task using real workload traces. The experimental results show that our approach provides substantial improvement over other heuristic algorithms in reducing energy consumption, number of VM migrations and number of SLA violations.

A virtual machine placement taxonomy

Abstract: Cloud computing data enters dynamically provide millions of virtual machines (VMs) in actual cloud markets. In this context, Virtual Machine Placement (VMP) is one of the most challenging problems in cloud infrastructure management, considering the large number of possible optimization criteria and different formulations that could be studied. VMP literature include relevant research topics such as energy efficiency, Service Level Agreement (SLA), Quality of Service (QoS), cloud service pricing schemes and carbon dioxide emissions, all of them with high economical and ecological impact. This work classifies an extensive up-to-date survey of the most relevant VMP literature proposing a novel taxonomy in order to identify research opportunities and define a general vision on this research area.

A service level agreement language for dynamic electronic services

Abstract: This paper proposes a novel language for Service Level Agreements (SLAs) for dynamic and spontaneous electronic services. In a cross-organizational setting, it is important for customers of a service to obtain, monitor and enforce quality of service (QoS) guarantees by service providers, usually expressed in the form of SLAs. Since the supervision and management of SLAs and the provisioning of corresponding systems should be automated for economic reasons, we need a formal language to define an SLA. If moreover, providers and customers want to sign custom-made SLAs, the SLA language, correspondingly, must provide a large degree of flexibility. The SLA language described in this paper aims at providing the needed flexibility by means of an XML-based representation and a runtime system for SLAs. Using this language, parties to a SLA can describe how parameters are measured and computed from raw metrics, the guarantees they want with respect to those parameters and the involvement of third parties to, e.g., verify independently SLA compliance.

Method and apparatus for maintaining a workload service level on a converged platform

Abstract: A management server is provided in a computer system having one or more hosts, one or more storage systems and one or more switches, the hosts having a plurality of virtual machines, each virtual machine being defined according to a service level agreement. The management server is operable to manage the virtual machines and resources associated with the virtual machines; receive a notification of an event from a node in the computer system; determine if the event affects a service level agreement for any of the virtual machines defined in the computer system, the service level agreements listing required attributes for the corresponding virtual machines; allocate a new resource for a virtual machine whose service level agreement is affected by the event; and move the virtual machine whose service level agreement is affected by the event to the newly allocated resource.

Service overlay networks: SLAs, QoS and bandwidth provisioning

Abstract: We advocate the notion of service overlay network (SON) as an effective means to address some of the issues, in particular end-to-end QoS, plaguing the current Internet, and to facilitate the creation and deployment of value-added Internet services such as VoIP, video-on-demand, and other emerging QoS-sensitive services. A SON purchases bandwidth with certain QoS guarantees from individual network domains via a bilateral service level agreement (SLA) to build a logical end-to-end service delivery infrastructure on top of existing data transport networks. Via a service contract, users directly pay the SON provider for using the value-added services provided by the SON. We study the bandwidth provisioning problem for a service overlay network which is critical to the cost recovery in deploying and operating value-added services over the SON. We mathematically formulate the bandwidth provisioning problem, taking into account various factors such as SLA, service QoS, traffic demand distributions, and bandwidth costs. Analytical models and approximate solutions are developed for both static and dynamic bandwidth provisioning. Numerical studies are also performed to illustrate the properties of the proposed solutions and demonstrate the effect of traffic demand distributions and bandwidth costs on the bandwidth provisioning of a SON.