Cloud computing systems fundamentally provide access to large pools of data and computational resources through a variety of interfaces similar in spirit to existing grid and HPC resource management and programming systems. These types of systems offer a new programming target for scalable application developers and have gained popularity over the past few years. However, most cloud computing systems in operation today are proprietary, rely upon infrastructure that is invisible to the research community, or are not explicitly designed to be instrumented and modified by systems researchers. In this work, we present EUCALYPTUS – an opensource software framework for cloud computing that implements what is commonly referred to as Infrastructure as a Service (IaaS); systems that give users the ability to run and control entire virtual machine instances deployed across a variety physical resources. We outline the basic principles of the EUCALYPTUS design, detail important operational aspects of the system, and discuss architectural trade-offs that we have made in order to allow Eucalyptus to be portable, modular and simple to use on infrastructure commonly found within academic settings. Finally, we provide evidence that EUCALYPTUS enables users familiar with existing Grid and HPC systems to explore new cloud computing functionality while maintaining access to existing, familiar application development software and Grid middle-ware. 1

Utility computing, elastic computing, and cloud computing are all terms that refer to the concept of dynamically provisioning processing time and storage space from a ubiquitous “cloud ” of computational resources. Such systems allow users to acquire and release the resources on demand and provide ready access to data from processing elements, while relegating the physical location and exact parameters of the resources. Over the past few years, such systems have become increasingly popular, but nearly all current cloud computing offerings are either proprietary or depend upon software infrastructure that is invisible to the research community. In this work, we present Eucalyptus, an open-source software implementation of cloud computing that utilizes compute resources that are typically available to researchers, such as clusters and workstation farms. In order to foster community research exploration of cloud computing systems, the design of Eucalyptus emphasizes modularity, allowing researchers to experiment with their own security, scalability, scheduling, and interface implementations. In this paper, we outline the design of Eucalyptus, describe our own implementations of the modular system components, and provide results from experiments that measure performance and scalability of an Eucalyptus installation currently deployed for public use. The main contribution of our work is the presentation of the first research-oriented open-source cloud computing system focused on enabling methodical investigations into the programming, administration, and deployment of systems exploring this novel distributed computing model. 1

Abstract: This is a position paper on multi-tenant databases. As motivation, it first describes the emerging marketplace of hosted enterprise services and the importance of using multi-tenancy to handle high traffic volumes at low cost. It then outlines the main requirements on multi-tenant databases: scale up by consolidating multiple tenants onto the same server and scale out by providing an administrative framework that manages a farm of such servers. Finally it describes three approaches to implementing multi-tenant databases and compares them based on some simple experiments. The main conclusion is that existing database vendors need to enhance their products to better support multi-tenancy. 1 Hosted Services and Multi-Tenancy In the hosted service model [GM02a, GM02b, Wa03], a service provider develops an application and operates the system that hosts it. Customers access the application over the Internet using industry-standard web browsers or Web Services clients. As the Internet has matured, hosted services have appeared for an increasingly wide variety of enterprise applications, including ones that manage sales, marketing, support, human resources, planning, manufacturing, inventory, financials, purchasing, and compliance [Th06]. While hosted services are attractive to all segments of the market, they are particularly appealing to small- to mediumsized businesses, which often lack the resources to maintain a complex data center. Hosted services are

Abstract: Educational institutions using enterprise software systems within their courses show a very particular behavior in system usage, different from that of operational businesses. This requires an adjusted operating and service model for the underlying IT systems. A service provider running and maintaining such educationally dedicated systems can meet bigger parts of these special requirements by implementing a flexible IT infrastructure which adapts to the customers ’ demands. We propose a concept based on a blade server architecture which allows a flexible handling of an SAP ® system landscape. The technical concept is embedded into a proposed model of providing services for educational institutions.

Cloud Computing extend the areas of virtualization, clustering, IT management, Web Architecture, Services-Oriented Architecture (SOA) and brings new dimension in extending utility computing. The primary aim of Cloud Computing is to provide mobility deployment of web-based application by means of easily accessible tools and interfaces for using and manipulating infrastructure. Cloud-based services integrate globally scattered resources, which offer its users seamless services without any glitches. There are three general categories of services offered in cloud computing. They are Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), and Software-as-a-Service (SaaS). SaaS is becoming an increasingly ubiquitous software delivery model that support implementation of service-oriented architecture using Web services technologies. With SaaS gaining mainstream popularity, enhanced by the advent of web based computing options and virtualization platforms, the enterprise infrastructure is rapidly expanding into a large computing blurb- a 'computing cloud'. SaaS is the key setting for the rapid development that Cloud Computing is creating. In this paper we investigated SaaS by describing their characteristics, reasons for adoption and applications. SaaS model make possible for every customer to take advantages of provider’s latest technological features without the burden of software maintenance, management, updates and upgrades. This paper also identifies the responsibilities of SaaS provider and the benefits to SaaS consumer.

Research on Software-as-a-Service has received an increasing attention. However, most of the existing literature focuses on the general business model, its adoption and diffusion or on the technological implementation. The impact potentials on a process level and especially on development processes have rarely been analyzed. The objective of this paper is the impact analysis of the key characteristics of the Software-as-a-Service concept on development processes of Softwareas-a-Service vendors. For this purpose, Software-as-a-Service definitions in research publications will be analyzed to extract the key characteristics of the concept. These are subsequently evaluated against their development process impact. Implications for the software and service development processes are derived to form a basis for an assessment of current methodologies. The results suggest the need for a continious process of software development and service operations actvities with a close linkage between the functions and high customer involvment. The service character challanges