Making Cloud-based Systems Elasticity Testing Reproducible

International audienceElastic cloud infrastructures vary computational resources at runtime, i. e., elasticity, which is error-prone. That makes testing throughout elasticity crucial for those systems. Those errors are detected thanks to tests that should run deterministically many times all along the development. However, elasticity testing reproduction requires several features not supported natively by the main cloud providers, such as Amazon EC2. We identify three requirements that we claim to be indispensable to ensure elasticity testing reproducibility: to control the elasticity behavior, to select specic resources to be unallocated, and coordinate events parallel to elasticity. In this paper, we propose an approach fullling those requirements and making the elasticity testing reproducible. To validate our approach, we perform three experiments on representative bugs, where our approach succeeds in reproducing all the bugs