http://emamispnu.persiangig.com/Projects/Cloud%20Computing/science_2.pdf

Review: A survey on security issues in service delivery models of cloud computing

Over the Internet today, computing and communications environments are significantly more complex and chaotic than classical distributed systems, lacking any centralized organization or hierarchical control. There has been much interest in emerging Peer-to-Peer (P2P) network overlays because they provide a good substrate for creating large-scale data sharing, content distribution, and application-level multicast applications. These P2P overlay networks attempt to provide a long list of features, such as: selection of nearby peers, redundant storage, efficient search/location of data items, data permanence or guarantees, hierarchical naming, trust and authentication, and anonymity. P2P networks potentially offer an efficient routing architecture that is self-organizing, massively scalable, and robust in the wide-area, combining fault tolerance, load balancing, and explicit notion of locality. In this article we present a survey and comparison of various Structured and Unstructured P2P overlay networks. We categorize the various schemes into these two groups in the design spectrum, and discuss the application-level network performance of each group.

/pdf/a-survey-and-comparison-of-peer-to-peer-overlay-network-cpcv2ij1hk.pdf

A survey and comparison of peer-to-peer overlay network schemes

Recent technology trends in the Web Services (WS) domain indicate that a solution eliminating the presumed complexity of the WS-* standards may be in sight: advocates of REpresentational State Transfer (REST) have come to believe that their ideas explaining why the World Wide Web works are just as applicable to solve enterprise application integration problems and to simplify the plumbing required to build service-oriented architectures. In this paper we objectify the WS-* vs. REST debate by giving a quantitative technical comparison based on architectural principles and decisions. We show that the two approaches differ in the number of architectural decisions that must be made and in the number of available alternatives. This discrepancy between freedom-from-choice and freedom-of-choice explains the complexity difference perceived. However, we also show that there are significant differences in the consequences of certain decisions in terms of resulting development and maintenance costs. Our comparison helps technical decision makers to assess the two integration styles and technologies more objectively and select the one that best fits their needs: REST is well suited for basic, ad hoc integration scenarios, WS-* is more flexible and addresses advanced quality of service requirements commonly occurring in enterprise computing.

/pdf/restful-web-services-vs-big-web-services-making-the-right-2tg7890x7z.pdf

Restful web services vs. "big"' web services: making the right architectural decision

Service-Oriented Computing (SOC) is a new computing paradigm that utilizes services as the basic constructs to support the development of rapid, low-cost and easy composition of distributed applications even in heterogeneous environments. The promise of Service-Oriented Computing is a world of cooperating services where application components are assembled with little effort into a network of services that can be loosely coupled to create flexible dynamic business processes and agile applications that may span organizations and computing platforms. The subject of Service-Oriented Computing is vast and enormously complex, spanning many concepts and technologies that find their origins in diverse disciplines that are woven together in an intricate manner. In addition, there is a need to merge technology with an understanding of business processes and organizational structures, a combination of recognizing an enterprise's pain points and the potential solutions that can be applied to correct them. The materi...

/pdf/service-oriented-computing-a-research-roadmap-iuym80iybz.pdf

Service-oriented computing: a research roadmap

Cloud storage enables users to remotely store their data and enjoy the on-demand high quality cloud applications without the burden of local hardware and software management. Though the benefits are clear, such a service is also relinquishing users' physical possession of their outsourced data, which inevitably poses new security risks toward the correctness of the data in cloud. In order to address this new problem and further achieve a secure and dependable cloud storage service, we propose in this paper a flexible distributed storage integrity auditing mechanism, utilizing the homomorphic token and distributed erasure-coded data. The proposed design allows users to audit the cloud storage with very lightweight communication and computation cost. The auditing result not only ensures strong cloud storage correctness guarantee, but also simultaneously achieves fast data error localization, i.e., the identification of misbehaving server. Considering the cloud data are dynamic in nature, the proposed design further supports secure and efficient dynamic operations on outsourced data, including block modification, deletion, and append. Analysis shows the proposed scheme is highly efficient and resilient against Byzantine failure, malicious data modification attack, and even server colluding attacks.

/pdf/toward-secure-and-dependable-storage-services-in-cloud-1h1z2suddd.pdf

Toward Secure and Dependable Storage Services in Cloud Computing

In the fast-paced global economy, a corporation must be flexible and agile to meet the shifting needs of operating in an on demand environment. Aligning information technology (IT) systems using service-oriented architecture (SOA) to provide end-to-end enterprise integration and virtualized IT services is a critical step. To be truly effective, however, the SOA paradigm also needs to be extended to transmute organizational structures and behavioral practices. In this paper, we first explore the governance, economic, and enterprise challenges to SOA-based IT transformation. Next, we raise the need to redesign the existing organizational models, and we propose the Human Services Bus (HSB), a new organizational structure that optimizes the workforce and streamlines cross-unit processes to leverage the new IT systems. Finally, we discuss the cultural transformation that is required to support the HSB transition and induce the changes required in management and behavioral practices. The issues and insights at all three layers-IT systems, organizational structures, and cultural practices-are based on IBM's experience with adopting on demand methods.

Impact of service-oriented architecture on enterprise systems, organizational structures, and individuals

This paper discusses the use of service-oriented architecture (SOA) as one of the key elements supporting business transformation at IBM. It describes the internal SOA strategy, SOA governance, organizational impacts, and several IBM internal SOA case studies. The top-down and bottom-up approaches to promoting SOA within the enterprise are also illustrated, along with a set of SOA business and information technology lessons learned.

L. Walker

Papers

Impact of service-oriented architecture on enterprise systems, organizational structures, and individuals

IBM business transformation enabled by service-oriented architecture