Resilient Edge Service Placement and Workload Allocation under Uncertainty

In this paper, we study an optimal service placement and workload allocation problem for a service provider (SP), who can procure resources from numerous edge nodes to serve its users.The SP aims to improve the user experience while minimizing its cost, considering various system uncertainties. To tackle this challenging problem, we propose a novel resilience-aware edge service placement and workload allocation model that jointly captures the uncertainties of resource demand and node failures. The first-stage decisions include the optimal service placement and resource procurement, while the optimal workload reallocation is determined in the second stage after the uncertainties are disclosed. The salient feature of the proposed model is that it produces a placement and procurement solution that is robust against any possible realization of the uncertainties. By leveraging the column-and-constraint generation method, we introduce two iterative algorithms that can converge to an exact optimal solution within a finite number of iterations. We further suggest an affine decision rule approximation approach for solving large-scale problem instances in a reasonable time. Extensive numerical results are shown to demonstrate the advantages of the proposed model and solutions.