ElaScript: a DSL for Coding Elasticity in Cloud Computing
Abstract
Some of the Cloud elasticity model’s main shortcomings refer to the low reactivity due to resource granularity and large start up time at the infrastructure layer. Prior work in the literature advocates that the software layer may take part in the global elasticity process in order to cope with these shortcomings and hence achieve efficient Cloud elasticity. In this paper, we introduce ElaScript, a Domain Specific Language which offers Cloud administrators a simple and concise way to define complex elasticity-based reconfiguration plans. ElaScript is capable of dealing with both infrastructure and software elasticities, independently or together, in a coordinated way. We validate our approach by first showing the interest to have a Domain Specific Language offering multiple levels of control for Cloud elasticity, and then by showing its integration with a realistic well-known application benchmark deployed in OpenStack and Grid’5000 infrastructure testbed. Results show the benefits of using ElaScript, and consequently the elasticity at the software layer, to improve system’s reactivity to environment’s changes.