An NFV Framework for Supporting Elastic Scaling of Service Function Chain

Enabling elastic scaling is the crucial advantage of Network Function Virtualization (NFV), of which the common usage is Service Function Chain (SFC). But how to scale SFC elastically on an NFV platform while ensuring performance and cost-effectiveness, remains to be vague and challenging. We propose ESFC, a user space service chain management framework to reallocate computing resource of each NF components dynamically based on real-time statistics, while minimizing performance overhead. The ESFC framework monitors load on a service chain at high frequency (1000Hz) and employs proactive resource allocation policy to enable elastic scaling. ESFC utilizes an asynchronous mechanism to notify the to-be-scaled NF, which will be reallocated with computing resources via thread. Moreover, ESFC adopts a perfect distribution algorithm to reduce cache invalidation and state migration while scaling, which are crucial to performance. The results show that ESFC could adjust the devoted resources dynamically and achieve up to 3x higher cost-effectiveness without compromising performance. Comparing with the latest popular SFC platform, ESFC achieves higher performance up to 1.3x under the same condition.