Auto-scaling Applications in the Cloud by Simple Indexes with Complex Loads

Applications executed in the cloud can exploit its elasticity features, varying dynamically the amount of leased resources so as to adapt to load variations and to guarantee quality of service. As auto-scaling has implications on execution costs, making optimal scaling choices is of paramount importance. This paper presents an analysis method based on offline benchmarking and simple models that allows to evaluate performance indexes useful to define scaling policies to be used by auto-scalers. The proposed approach relies on a fixed set of benchmarks, to be executed off-line and a set of models that enable prediction of the same performance indexes under different workload conditions, enabling the analyst to perform parameter analysis when defining an auto-scaling policy.