CSADE: a delay-sensitive scheduling method based on task admission and delay evaluation on edge–cloud collaboration

Compared with cloud computing, edge–cloud collaboration can avoid long transmitting delay to cloud since tasks are close to edge, which makes edge–cloud collaboration suitable for delay-sensitive applications. However, the complex environment of edge–cloud poses new challenge to task scheduling. A Collaborative Scheduling strategy based on task Admission and Delay Evaluation (CSADE) is proposed to deal with the challenge and ensure the quality of service (QoS). In order to schedule maximum tasks to edge and guarantee QoS, a new dynamic delay model in resource manager is proposed to accurately estimate the average delay. Based on the average delay and execution time, task evaluator prevents the impossible tasks to avoid waste of resources on both edge and cloud. The scheduling policy in task scheduler fully leverages the conditions of edge, cloud and tasks to guarantee the QoS. The fault-tolerant mechanism would launch and adjust the scheduling strategy when task Scheduling in emergencies and resource node failures. Thus CSADE ensures the QoS for delay-sensitive applications from three levels, i.e., the accurate quantitative system delay in resource manager, the strict task admission evaluation in task evaluator, the edge-first elastic scheduling strategy and the fault-tolerant mechanism in task scheduler. Comparative experimental results on simulated datasets and real datasets verify that CSADE can reduce average delay time and QoS violation rate obviously.