SLA-Based and Consumer-centric Dynamic Provisioning for Cloud Databases

One of the main advantages of the cloud computing paradigm is that it simplifies the time-consuming processes of hardware provisioning, hardware purchasing and software deployment. Currently, we are witnessing a proliferation in the number of cloud-hosted applications with a tremendous increase in the scale of the data generated as well as being consumed by such applications. Cloud-hosted database systems powering these applications form a critical component in the software stack of these applications. Service Level Agreements (SLA) represent the contract which captures the agreed upon guarantees between a service provider and its customers. The specifications of existing service level agreement (SLA) for cloud services are not designed for flexibly handling even relatively straightforward performance and technical requirements of consumer applications. The concerns of consumers for cloud services regarding the SLA management of their hosted applications within the cloud environments will gain increasing importance as cloud computing becomes more pervasive. This paper introduces the notion, challenges and the importance of SLA-based provisioning and cost management for cloud-hosted databases from the consumer perspective. We present an end-to-end framework that acts as a middleware which resides between the consumer applications and the cloud-hosted databases. The aim of the framework is to facilitate adaptive and dynamic provisioning of the database tier of the software applications based on application-defined policies for satisfying their own SLA performance requirements, avoiding the cost of any SLA violation and controlling the monetary cost of the allocated computing resources. The experimental results demonstrate that SLA-based provisioning is more adequate for providing consumer applications the required flexibility in achieving their goals.