Dealing with Scale and Adaptation of Global Web Services Management
Service Oriented Architectures (SOA) are becoming the prevalent approach for realizing modern services and systems. SOA offers superior support for autonomy (decoupling) and heterogeneity compared to previous generation middleware systems, resulting in more scalable and adaptive solutions. However, SOA have not adequately addressed management, while traditional management solutions do not sufficiently scale to address the needs of (global) Web services. We propose scalable management based on models and industry standards. We discuss a use case for global service management, we present its design, implementation and preliminary evaluation. We retain all the benefits of SOA while also enabling global scale manageability. Our approach provides manageability that is comprehensible for administrators yet automated enough for integration into autonomous systems.
The increasing scale and complexity of systems and services makes them increasingly difficult and expensive to administer. In addition, traditional enterprise data centers are being complemented with so called closet computers emerging from remote and home offices. New computing models, such as Utility Computing [1, 2], Grid Computing , and PlanetLab grow even more significantly in scale. Service Oriented Architectures (SOA)  contribute to increased scale and availability of services, but they do not sufficiently address the management of services. An update at a moderately-sized data center may require changes to software on thousands of machines. In the case of global services in a large enterprise, a software update may require touching hundreds of data centers. In addition, there may be interdependencies among the services. For example, a Web-based e-commerce application may consist of a virtual store, catalog, customer relationship, and billing services, among many others. At the infrastructure level, this application is usually mapped on a three-tier system architecture, comprising the database, application, and Web server tiers. The application tier further consists of the application server, the application in question, and other services on which the application depends. Large scale data centers in financial, public and private sector, etc. can be significantly larger in size with significantly more complex services. As services become globally deployed, the design assumptions are changing. Scalability requirements change as administrative boundaries are cross. Availability needs change as companies move from expensive, private networks with well defined policies to the to the Internet and poorly-defined policies and best practices. Such shifts require adaptation to unexpected loads, rebooting and upgrading of machines, networks, and services. As the systems continue to grow in size and global deployment, the traditional management approaches become less effective. To address these new requirements, we propose a new way of scalable management, based on the use of models and standardsbased interfaces. The work presented in this paper is related to our work on approaches to service deployment and on scalable communication described elsewhere [8, 9]. The rest of the paper is organized in the following manner. In Section 2 we overview related standards in the management area. Section 3 presents a use case scenario. In Section 4 we describe our solution. We evaluate this solution in Section 5 followed by lessons learned in Section 6. In Section 7 we discuss how our solution can be extended and then we compare it to the related work in Section 8. Finally, in Section 9 we present the summary and future work.