The evolution of cloud computing over the past few years is potentially one of the major advances in the history of computing. However, if cloud computing is to achieve its potential, there needs to be a clear understanding of the various issues involved, both from the perspectives of the providers and the consumers of the technology. While a lot of research is currently taking place in the technology itself, there is an equally urgent need for understanding the business-related issues surrounding cloud computing. In this article, we identify the strengths, weaknesses, opportunities and threats for the cloud computing industry. We then identify the various issues that will affect the different stakeholders of cloud computing. We also issue a set of recommendations for the practitioners who will provide and manage this technology. For IS researchers, we outline the different areas of research that need attention so that we are in a position to advice the industry in the years to come. Finally, we outline some of the key issues facing governmental agencies who, due to the unique nature of the technology, will have to become intimately involved in the regulation of cloud computing.

Cloud computing - The business perspective

We describe a novel framework for specifying and monitoring Service Level Agreements (SLA) for Web Services. SLA monitoring and enforcement become increasingly important in a Web Service environment where enterprise applications and services rely on services that may be subscribed dynamically and on-demand. For economic and practical reasons, we want an automated provisioning process for both the service itself as well as the SLA managment system that measures and monitors the QoS parameters, checks the agreed-upon service levels, and reports violations to the authorized parties involved in the SLA management process. Our approach to these issues is presented in this paper. The Web Service Level Agreement (WSLA) framework is targeted at defining and monitoring SLAs for Web Services. Although WSLA has been designed for a Web Services environment, it is applicable as well to any inter-domain management scenario, such as business process and service management, or the management of networks, systems and applications in general. The WSLA framework consists of a flexible and extensible language based on XML Schema and a runtime architecture comprising several SLA monitoring services, which may be outsourced to third parties to ensure a maximum of objectivity. WSLA enables service customers and providers to unambiguously define a wide variety of SLAs, specify the SLA parameters and the way they are measured, and relate them to managed resource instrumentations. Upon receipt of an SLA specification, the WSLA monitoring services are automatically configured to enforce the SLA. An implementation of the WSLA framework, termed SLA Compliance Monitor, is publicly available as part of the IBM Web Services Toolkit.

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The WSLA Framework: Specifying and Monitoring Service Level Agreements for Web Services

The emerging cloud-computing paradigm is rapidly gaining momentum as an alternative to traditional IT (information technology). However, contemporary cloud-computing offerings are primarily targeted for Web 2.0-style applications. Only recently have they begun to address the requirements of enterprise solutions, such as support for infrastructure service-level agreements. To address the challenges and deficiencies in the current state of the art, we propose a modular, extensible cloud architecture with intrinsic support for business service management and the federation of clouds. The goal is to facilitate an open, service-based online economy in which resources and services are transparently provisioned and managed across clouds on an ondemand basis at competitive costs with high-quality service. The Reservoir project is motivated by the vision of implementing an architecture that would enable providers of cloud infrastructure to dynamically partner with each other to create a seemingly infinite pool of IT resources while fully preserving their individual autonomy in making technological and business management decisions. To this end, Reservoir could leverage and extend the advantages of virtualization and embed autonomous management in the infrastructure. At the same time, the Reservoir approach aims to achieve a very ambitious goal: creating a foundation for next-generation enterprise-grade cloud computing.

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The reservoir model and architecture for open federated cloud computing

https://papers.ssrn.com/sol3/Delivery.cfm/SSRN_ID1732819_code423677.pdf?abstractid=1413545&rulid=55918&mirid=1

Cloud Computing: The Business Perspective

SLA monitoring is difficult to automate as it would need precise and unambiguous specification and a customizable engine that collects the right measurement, models the data and evaluates the SLA at certain times or when certain events happen Also most of the SLA neglect client side measurement or restrict SLAs to measurements based only on server side In a cross-enterprise scenario like web services it will be important to obtain measurements at multiple sites and to guarantee SLAs on them In this article we propose an automated and distributed SLA monitoring engine

/pdf/automated-sla-monitoring-for-web-services-11pfxugb29.pdf

Automated SLA Monitoring for Web Services

SLA management in federated environments

A method and apparatus are provided for evaluating Service Level Agreements (SLAs) that describe the level of services that are to be provided to customers by Internet Service Providers (ISPs) or Enterprise Service Providers (ESPs). The method and apparatus are utilized to measure the quality of service being provided to customers and to determine whether or not the quality of service is in compliance with an SLA that characterizes the level of service to be provided to customers. Such services include, for example, electronic mail (e-mail), Voice-Over-IP (Voice Over Internet protocol), networking services and web hosting.

Method and apparatus for processing quality of service measurement data to assess a degree of compliance of internet services with service level agreements

Preeti Bhoj, Srinivas Ramanathan, Sharad Singhal Internet Systems and Applications Laboratory HP Laboratories Palo Alto HPL-2000-61 May, 2000 Web services, quality of service, service management The recent outages and brown-outs at several large Internet portal sites (trading, auction, etc.) and the associated loss in revenues highlight the central role that web-based services play in the -commerce era. Unpredictable demands posed byE sudden surges of requests from users on the open Internet have made it extremely difficult for web site operators to offer predictable quality of service (QoS). In order to provide stable service to users considered important by the site operator under these conditions, it is imperative that systems handle overloads gracefully. In this paper, we describe the design and implementation of a QoS-enabled web server called the Web2K server. The Web2K server enables web site operators to optimize the usage of their web sites by prioritizing among requests from different classes of users. Under overload conditions, predictive queue controllers incorporated in the Web2K server enable it to selectively deny service to some percentage of requests based on the associated user classification. Unlike current web servers, the Web2K server also maintains stable response times under overload using a novel, traffic-aware request processing model. A primary concern of operators while deciding to deploy QoS solutions relates to the overall impact of QoS provisioning on the capacity of their servers. To address this issue we present a comprehensive performance study that quantifies the overheads of a Web2K server and demonstrates its significant benefits. 

http://www.hpl.hp.com/techreports/2000/HPL-2000-61.pdf

Web2K: Bringing QoS to Web Servers

Increasingly, services such as E-commerce, Web hosting, application hosting, etc., are being deployed over an infrastructure that spans multiple control domains. These end-to-end services require cooperation and internetworking between multiple organizations, systems and entities. Currently, there are no standard mechanisms to share selective management information between the various service providers or between service providers and their customers. Such mechanisms are necessary for end-to-end service management and diagnosis as well as for ensuring the service level obligations between a service provider and its customers or partners. In this paper we describe an architecture that uses contracts based on service level agreements (SLA) to share selective management information across administrative boundaries. We also describe the design of a prototype implementation of this architecture that has been used by us for automatically measuring, monitoring, and verifying service level agreements for Internet services.

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Preeti Bhoj

Papers

SLA management in federated environments

Method and apparatus for processing quality of service measurement data to assess a degree of compliance of internet services with service level agreements

Web2K: Bringing QoS to Web Servers

SLA management in federated environments