Dynamic resource scaling is a key property of cloud computing. Users can acquire or release required capacity for their applications on-the-fly. The most widely used and practical approach for dynamic scaling based on predefined policies (rules). For example, IaaS providers such as RightScale ask application owners to manually set the scaling rules. This task assumes, that the user has expertise knowledge about the application being run on the cloud. However, it is not always true. In this paper, the authors propose a lightweight adaptive multi-tier scaling framework VscalerLight, which learns scaling policy online. Their framework performs fine-grained vertical resource scaling of multi-tier web application.