Towards Reducing Last-Level-Cache Interference of Co-Located Virtual Network Functions

摘要

Network Function Virtualization (NFV) aims to virtualize compute resources for packet processing in order to gain flexibility and reduce costs. In order to increase the resource utilization, multiple VNFs are co-located on one single server. Current virtualization techniques do not fully isolate all resources, thus co-location of VNFs causes interference effects. It has been shown that these interference effects can degrade the performance of Virtualized Network Functions (VNFs) in terms of throughput and delay severely. In this work we aim to gather the potential that lies in reduction of the interference due to the shared Last Level Cache (LLC). CPU caches are used to improve the access times to memory that is needed regularly for the execution of a program. Intel Cache Allocation Technology (CAT) provides the means to allocate the cache and isolate VNFs from each other. The results show that the scheduler can decrease the CPU utilization by up to 20%. We can show which factors influence the gain of LLC scheduling in NFV deployments. In order to show this we propose a scheduler which optimally allocates the LLC in order to reduce the maximum CPU utilization of all cores.