Joint optimization of function mapping and preemptive scheduling for service chains in network function virtualization

摘要

The idea of Network Function Virtualization (NFV) is to decouple of network functions from dedicated hardwares to obtain higher flexibility in terms of network management and maintenance. Although the problem of function placement and scheduling in NFV has drawn much attention in recent years, existing studies only consider the precedence constraints between network functions within a service but lacking for the interactions among services. In this paper, under the premise of satisfying the precedence conditions of forming the service chain, we study how to minimize the completion time of the whole system through efficient mapping and preemptive scheduling of functions for multiple service chains. We firstly model this issue as an Integer Linear Programming (ILP) problem. To avoid the computational complexity of ILP, an online preemptive algorithm is designed. Extensive simulations are conducted to validate the effectiveness of the proposed algorithm. The simulation results indicate that our algorithm is suitable for placement and scheduling of functions for multiple service chains in NFV.