关键词: 移动边缘计算, 延时优化, 容错策略, 免疫算法, 粒子群算法, 服务工作流

Abstract: To address the problem of service workflow delay optimization and workflow task execution failure in Mobile Edge Computing (MEC) environment,a Fault Tolerant Immune Particle Swarm Optimization Scheduling Algorithm (FT-IPSO) for service workflow was proposed.The Heterogeneous Earliest Finish Time (HEFT) algorithm was used to calculate the weight of task and generate the ready queue.The mixed fault-tolerant strategy was added to the service workflow scheduling process to ensure the workflow continue to execute after the task fails.The particle swarm optimization algorithm was used to quickly find the optimal scheduling scheme and incorporates an immune algorithm to ensure the global optimization of the particle.To map out the scheduling position of the prime and backup version of task,the encoding scheme had been redesigned using integer.The task was scheduled according to the optimal scheduling scheme obtained by the algorithm.The simulation result showed that FT-IPSO algorithm reduced the service task failure rate and optimizes the service delay about 4.1%,6.3% and 9.1% compared with the RFTA,CRCH and C-HEFT algorithms respectively.

Key words: mobile edge computing, delay optimization, fault-tolerant strategy, immune algorithm, particle swarm optimization algorithm, service workflow