Research On Reusable Component Based On Multi-Tenancy’ SLA On Paas Platform

As the development of cloud service, the mode of how to deploy and use has been changed. As one of the patterns of cloud service, PaaS provides an entire development, deployment and runtime platform for SaaS applications. In an open PaaS environment such as e-commerce platform, there are similar functionalities among multiple applications, such as most of the online shops has the functionality of "searching items". In this paper, we focus on researching on enhancing general PaaS platform with the mechanism of shared component-based application construction. There are some key issues of constructing such abilities with large number of heterogeneous components in the PaaS platform. First, how to organically combine the mechanism of reusable component with PaaS platforms; Second, how to manage the components on the PaaS platform; Third, in view of the multi-tenant SaaS application characteristics, how to bind components in order to better meet the SLA made by different tenants?In this paper, We discuss the key issues of constructing such abilities with large number of heterogeneous components in the PaaS platforn. First, in order to construct SaaS based on the reusable component, we provide an enhanced e-commerce PaaS platform with an added component layer. The component layer is responsible for storing and invoking component. Second, as the component developer to submit artifacts in the component layer, the number of components will be more and more, and there will be a lot of components have similar function. In order to be able to better manage these artifacts and let it be convenient for SaaS application developers to retrieve their required components, we put forward the concept of abstract component. Abstract component is the generalization of components with similar functions; it involves only components of abstract description without specific implementation. By abstracting the similarity between the component and the real components, we will have similar function of component clustering to the same abstract component. At last, SaaS application has the characteristics of "single instance multi-tenant" namely multiple tenants tenant the same application instance. But different tenants often make different SLA agreements with SaaS application providers, in the SLA agreements, tenant specify the quality of service they want to be apply. In order to meet the SLA request of multi-tenancy, we put forward a component late binding strategies, namely after the tenants make SLA agreement with SaaS application providers according to the tenants’ request, and then select the appropriate component to call. From all the components that meet the functional requirements of SaaS application providers to select a component that can meet tenants’ SLA request have to comprehensively consider the multiple QoS attributes of components, namely from multiple QoS goals to select one of the most suitable components for the tenant. SaaS providers located between the component providers and application tenants, they not only need to consider satisfy the request of the tenant but also consider how to make their own benefit maximization. We have considered if there are components that can meet the tenants’ requested, how to select appropriate component invocation.Finally, the paper has carried on the experimental simulation, based on abstract component model is verified by simulation experiment to the component management and the feasibility of the component late binding based on SLA.