Failure-resilient DAG Task Rescheduling in Edge Computing

Abstract

By deploying computation and storage resources at the network edge that is close to the data source,and scheduling tasks offloaded by users efficiently,edge computing can greatly improve the quality of experience (QoE) of users.However,due to the lack of the reliable infrastructure support,the failure of edge servers or communication links could easily fail the edge computing service.To handle this problem,we establish the failure models of the computing nodes and communication links in edge computing,and then propose the rescheduling algorithm DaGTR (Dependency-aware Greedy Task Rescheduling) for the scheduling of dependent user tasks in resource failure scenarios.DaGTR includes two sub-algorithms,DaGTR-N and DaGTR-L,which are responsible for handling the node and link failure events respectively.DaGTR can sense the data dependency of tasks,and reschedule the tasks affected by failure events based on greedy method to ensure the successful execution of each task.Simulation results show that the algorithm can effectively avoid the task failure caused by failure events and improve the success rate of tasks in the case of resource failure.

Keywords

• edge computing|directed acyclic graph|task scheduling|resource failure