Optimizing VNF live migration via para-virtualization driver and QuickAssist technology

Live migration of virtual network functions (VNF) is a powerful technique with benefits of server maintenance, resource management and dynamic workload re-balance, among others. Downtime and total migration time are mainly two vital indicators to describe the performance of the VNF live migration (VLM). Modern research has effectively reduced the downtime to zero for some specific VNFs (eg. virtual router). However, for general VNFs predominantly leveraging pre-copy approach, such as firewalls, network address translators (NAT), load balancers, etc., there still remain some intractable problems: inevitable service downtime and long migration time on account of large amount of data transferred during migration, both of which result in a severe performance degradation of VNF services. To resolve these issues, we present a solution called PV-QAT to accelerate the migration process for these general VNFs. The PV-QAT creatively exploits the Para-Virtualization (PV) driver to filter out the useless memory pages in the process of migration, and unprecedentedly applies QuickAssist Technology (QAT) to provide fast compression of memory pages with low overhead, The experimental results show that PV-QAT can significantly reduce 77.5% of downtime and 80.5% of total migration time on average when compared with original pre-copy migration of KVM.