Remediating Overload in Over-Subscribed Computing Environments

Resource over subscription brings the risk of resource overload. This paper proposes a mechanism to remediate overload without assuming there is always resource available for migration. A work value notion is introduced to compare importance of VMs, and the overload remediation problem is formulated as a variant of Removable Online Multi-Knapsack Problem. An algorithm is proposed to solve this optimization problem. The mechanism is implemented in a large commercial Cloud environment. Experiments and model-based studies demonstrate the effectiveness of the proposed mechanism in remediating overload and its performance in maximizing work values provided by computing environments (27% higher work values than the baseline algorithm in our study).