  Resilience functionality, including failure resilience and flow migration, is
of pivotal importance in practical network function virtualization (NFV)
systems. However, existing failure recovery procedures incur high packet
processing delay due to heavyweight process-checkpointing, while flow migration
has poor performance due to centralized control. This paper proposes NFVactor,
a novel NFV system that aims to provide lightweight failure resilience and
high-performance flow migration. NFVactor enables these by using actor model to
provide a per-flow execution environment, so that each flow can replicate and
migrate itself with improved parallelism, while the efficiency of the actor
model is guaranteed by a carefully designed runtime system. Moreover, NFVactor
achieves transparent resilience: once a new NF is implemented for NFVactor, the
NF automatically acquires resilience support. Our evaluation result shows that
NFVactor achieves 10Gbps packet processing, flow migration completion time that
is 197 times faster than existing system, and packet processing delay stablized
at around 20 microseconds during replication.
