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.

Towards Self-Manageable Cloud Services

Abstract: Cloud computing represents a promising computing paradigm, where computational power is provided as a utility. An important characteristic of Cloud computing, other than in similar paradigms like Grid or HPC computing, is the provision of non-functional guarantees to users. Thereby, applications can be executed considering predefined execution time, price, security or privacy standards, which are guaranteed in real time in form of Service Level Agreements (SLAs). However, due to changing components, workload, external conditions, hardware, and software failures, established SLAs may be violated. Thus, frequent user interactions with the system, which are usually necessary in case of failures, might turn out to be an obstacle for the success of Cloud computing. In this paper we discuss self-manageable Cloud services. In case of failures, environmental changes, and similar, services manage themselves automatically following the principles of autonomic computing. Based on the life cycle of a self-manageable Cloud service we derive a resource submission taxonomy. Furthermore, we present an architecture for the implementation of self-manageable Cloud services. Finally, we discuss the application of autonomic computing to Cloud services based on service mediation and negotiation bootstrapping case study.

A method and apparatus for forecasting future values of a time series

Abstract: A method of predicting at least one future value of a time series of data using a neural network by inputting information about a time such as the current time, into the neural network. For example, bandwidth levels can be predicted to forecast when bandwidth levels will exceed capacity or previously agreed threshold levels. The agreed levels may be specified, for example, in a service level agreement between a service provider and a customer. The predictor also predicts, how much excess there will be and how long this will occur for. This information is provided to the service provider/customer and also can be provided to an agent which comprises a computer system. This agent negotiates on behalf of the service provider (for example) and in this way new terms for an agreement between the two parties is obtained

Managing violations in service level agreements

Abstract: A Service Level Agreement (SLA) represents an agreement between a service user and a provider in the context of a particular service provision. SLAs contain Quality of Service properties that must be maintained by a provider. These are generally defined as a set of Service Level Objectives (SLOs). These properties need to be measurable and must be monitored during the provision of the service that has been agreed in the SLA. The SLA must also contain a set of penalty clauses specifying what happens when service providers fail to deliver the preagreed quality. Although significant work exists on how SLOs may be specified and monitored, not much work has focused on actually identifying how SLOs may be impacted by the choice of specific penalty clauses. The participation of a trusted mediator may be necessary to resolve conflicts between involved parties. The main focus of the paper is on identifying particular penalty clauses that can be associated with an SLA.

Evaluating Service Level Agreement Violations

Abstract: A technique for evaluating service level agreement (SLA) violations occurring in a computing system with agreed-upon model for exemptions is provided. The technique includes storing in a memory a model of the SLA and identifying occurrence of an SLA violation in a computing system that is providing services under the SLA. Based on the stored model, the technique further determines if the SLA violation is exempted from a penalty.

QoS-Aware VNF Placement Optimization in Edge-Central Carrier Cloud Architecture

Abstract: Cloud computing and Network Function Virtualization (NFV) represent together a promising solution for wireless network operators to improve business agility and cope with the continuing growth in data traffic. Furthermore, the use of edge clouds in association with a centralized cloud, referred to as the edge-central cloud, notably improves user experience while ensuring scalability and load balancing. In such carrier cloud environment, efficient management mechanisms for the Virtualized Network Functions (VNFs) are of crucial importance. In this paper, we introduce VNF placement and provisioning optimization strategies over an edge- central carrier cloud infrastructure taking into account Quality of Service (QoS) requirements (i.e., response time, latency constraints and real-time requirements) and using queuing and QoS models. Our main design goals are to optimize resource utilization, to prevent cloudlet overload, and to avoid violation of Service Level Agreement (SLA) requirements. Through extensive simulations, we show how a trade-off can be achieved between these conflicting objectives.