An autonomic approach to manage elasticity of business processes in the Cloud

Cloud Computing is gaining more and more importance in the Information Technologies (IT) scope. One of the major assets of this paradigm is its economic model based on pay-as-you-go model. Cloud Computing gets more attention from IT users when it fits their required QoS and reduces their expenses. This task cannot be done without increasing the autonomy of the provisioned Cloud resources. In this paper, we propose a holistic approach that allows to dynamically adding autonomic management facilities to Cloud resources even if they were designed without these facilities. Based on the Open Cloud Computing Interface (OCCI) standard, we propose a generic model that allows describing the needed resources to render autonomic a given Cloud resource independently of the service level (Infrastructure, Platform or Software). Herein, we define new OCCI Resources, Links and Mixins that allow provisioning autonomic Cloud Resources. In order to illustrate our approach, we propose a use case that specializes our autonomic infrastructure to ensure the elasticity of Service-based Business Processes (SBPs). The elasticity approach that we are using is based on a formal model that features duplication/consolidation mechanisms and a generic Controller that defines and evaluates elasticity strategies. To validate our proposal, we present an end to end scenario of provisioning an elastic SBP on a public PaaS. Evaluation of our approach on a realistic situation shows its efficiency.