Service level

About: Service level is a research topic. Over the lifetime, 7647 publications have been published within this topic receiving 126093 citations. The topic is also known as: service level.

SLA-driven planning and optimization of enterprise applications

Abstract: We propose a model-based methodology to size and plan enterprise applications subject to Service Level Agreements (SLAs). Our approach is illustrated using a real-world Enterprise Resource Planning (ERP) application, namely SAP ERP. Firstly, we develop a closed queueing network model with finite capacity regions describing the SAP ERP application performance and show that this model is effective and robust in capturing measured response times and utilizations. Secondly, we propose an analytical cost model that jointly accounts for fixed hardware costs and dynamic operational costs related to power consumption.Based on the developed performance and cost models, we propose to use multi-objective optimization to find the Pareto-optimal solutions that describe the best trade-off solutions between conflicting performance and cost-saving goals. Experimental validation demonstrates the accuracy of the proposed models and shows that the attained Pareto-optimal solutions can be efficiently used by service providers for SLA-driven planning decisions, thus making a strong case in favor of the applicability of our methodology for deployment decisions subject to different SLA requirements.

The role of service level agreements in IT service delivery

Abstract: Introduces the concept of service level agreements (SLAs) in IT service provision, especially in the case of outsourced service provision. Reports the experience of several consulting engagements and surveys to substantiate suggested frameworks and checklists. Discusses the reasons for exercising rigour around SLAs. Differentiates between SLAs negotiated for internal versus external service providers. Describes the structure of good service level agreements. Outlines the most important elements of measurement for monitoring service level performance. Concludes with the importance of SLAs to the management of commercial relationships in which services are provided.

Peering and provisioning of differentiated Internet services

Abstract: A key consideration in building differentiated network services is the feasibility of maintaining stable and consistent service level agreements across multiple networks where allocations are made only on the edges. To investigate this, we consider a game theoretic model of capacity provisioning in a differentiated services Internet. The players are one raw-capacity seller per network, one broker per service per network, and users, to play the roles of wholesellers, retailers and end users respectively in a two-tier wholeseller/retailer market. Based on this model, we are able to construct an explicit necessary and sufficient condition for the stability of the game, which determines the sustainability of a given set of SLA configurations among peering ISP. The analytical results are validated with simulations of user and broker dynamics, using distributed progressive second price auctions as the spot market mechanism in a scenario with three interconnected networks, and two services.

SLA validation in layered cloud infrastructures

Abstract: Cloud computing brings in a novel paradigm to foster ITbased service economy in scalable computing infrastructures by allowing guaranteed on-demand resource allocation with flexible pricing models. Scalable computing infrastructures not only require autonomous management abilities but also the compliance to users' requirements through Service Level Agreements (SLAs). Such infrastructures should automatically respond to changing components, workload, and environmental conditions as well as prevent violations of agreed SLAs. The essential requirements for SLA-based orchestration of services include agile component-based infrastructure to support these orchestrations; proactive validation of SLAs to prevent violations; and business enabling requirements including trust, privacy and breach management to address penalty enforcement, renegotiation and recovery. In this paper we outline a systematic approach that weaves together three different SLA management models, which cater the above mentioned issues by localizing and addressing them at different but interrelated scopes pertaining to resource, infrastructure, and business domains. In our framework Cloud components (e.g., meta negotiator, broker, automatic service deployer) are loosely coupled using SLAs and can be exchanged on demand considering current load, systems failures, and the whole Cloud ecosystem. Thereafter, SLAs are validated based on high level goals (e.g., business rules, VO policies) ensuring trust, privacy, and breach management in layered Cloud infrastructures.