Software-as-a-Service (SaaS) providers are influenced by a variety of characteristics and capabilities of the available cloud infrastructure resources (IaaS). As a result, the decision made by business service owners to lease and use certain resources is an important one in order to achieve the planned outcome. This chapter uses value based approach to manage the SaaS service provided to the customers. Based on our approach, customer satisfaction is modeled not only based on the response time, but also based on the allotted budget. Using our model, the application owner is able to direct and control the decision of renting cloud resources as per the current strategy. This strategy is led by a set of defined key performance indicators. In addition, we present a scheduling algorithm that can bid for different types of virtual machines to achieve the target value. Furthermore, we proposed the required Ontology to semantically discover the needed IaaS resources. We conduct extensive simulations using different types of Amazon EC2 instances with dynamic prices.
TopIntroduction
The high cost and effort required to operate traditional business applications makes it very important to improve organizational efficiency and to reduce operational cost. With cloud computing, the shared infrastructure and services made it possible to mitigate those issues by presenting it as a utility, where you only pay for what you need and transfer the headache of operation, maintenance and upgrade to the other party.
The use of Cloud systems leads to promising business models and benefits for both of the providers and end-users (Armbrust et al., 2009). These benefits may include greater efficiency, increased agility, improved compliance, reduced costs, and limitless ability to scale and to provide on-demand resources.
As illustrated in Figure 1, a cloud can offer three service models: Software as a Service, Platform as a Service, and Infrastructure as a Service (Litoiu, Ng, & Iszlai, 2010).
Figure 1. Cloud computing deployment models
Software as a Service (SaaS)
Software as a Service is the delivery of software functionality through the internet, this functionality is similar to the one installed on a local machine. Buyya et al. (2010) provide examples of the SaaS services including the services that are provided by Google for office automation, this includes Google Mail, Google Documents, and Google Calendar. SalesForce.com is a provider of commercial solution which provides online CRM (Customer Relationship Management). Another commercial solution provider is Clarizen.com which provides a project management services. Appirio is an integrated solution that provides complete support for any management aspect of modern enterprises from project management to resource planning.
It is a service model where all resources required to build applications are provided through the internet without the need to install software. Examples of such platforms are the application servers and database servers. Google AppEngine, Microsoft Azure, and Manjrasoft Aneka are examples of PaaS services and their providers.
Infrastructure as a Service (IaaS)
It is a service model where the hardware is provided to the consumer as a service, this includes the processing capability, network connectivity, memory, and storage space in the form of a set of virtual machines. Amazon EC2, Amazon S3, Nirvanix, GoGrid are examples of IaaS services and providers.
The remainder of the chapter is organized as follows: background section comes next, followed by a detailed literature review. Research methodology is summarized in a separate section, while the developed model is presented in the problem description section. The value based management framework section describes the proposed framework including the needed components to implement the model. Experimental setup section describes the simulation set up of the proposed model. The evaluation and experiments of our approach are presented in the evaluation section Last, the summary and future works is presented.
Background
The different available service models of Cloud Computing paradigm have made it more feasible for service providers to deliver their services as a utility to the customers in different methods. According to Litoiu et al. (2010), this is mainly and specifically due to: Virtualization and Software as a Service Model. Virtualization is a process in which the organization provides its physical resources through a set of virtual resources. Those virtual resources may have different characteristics and may work using different configurations on the top of the physical resources. Using this virtualized environment allows for physical resource utilization.
Four main deployment models can be recognized for clouds (Smyth, 2009):