Cloud Computing: Principles and Paradigms

Chapter 16. SLA MANAGEMENT IN CLOUD COMPUTING: A SERVICE PROVIDER'S PERSPECTIVE

SUMIT BOSE, ANJANEYULU PASALA, DHEEPAK RAMANUJAM A, SRIDHAR MURTHY and GANESAN MALAIYANDISAMY

INSPIRATION

In the early days of web-application deployment, performance of the application at peak load was a single important criterion for provisioning server resources [1]. Provisioning in those days involved deciding hardware configuration, determining the number of physical machines, and acquiring them upfront so that the overall business objectives could be achieved. The web applications were hosted on these dedicated individual servers within enterprises' own server rooms. These web applications were used to provide different kinds of e-services to various clients. Typically, the service-level objectives (SLOs) for these applications were response time and throughput of the application end-user requests. The capacity buildup was to cater to the estimated peak load experienced by the application. The activity of determining the number of servers and their capacity that could satisfactorily serve the application end-user requests at peak loads is called capacity planning [1].

An example scenario where two web applications, application A and application B, are hosted on a separate set of dedicated servers within the enterprise-owned server rooms is shown in Figure 16.1. The planned capacity for each of the applications to run successfully is three servers. As the number of web applications grew, the server ...