The increasing reliance upon cloud services entails more flexible networks
that are realized by virtualized network equipment and functions. When such
advanced network systems face a massive failure by natural disasters or
attacks, the recovery of the entire system may be conducted in a progressive
way due to limited repair resources. The prioritization of network equipment in
the recovery phase influences the interim computation and communication
capability of systems, since the systems are operated under partial
functionality. Hence, finding the best recovery order is a critical problem,
which is further complicated by virtualization due to dependency among network
nodes and layers. This paper deals with a progressive recovery problem under
limited resources in networks with VNFs, where some dependent network layers
exist. We prove the NP-hardness of the progressive recovery problem and
approach the optimum solution by introducing DeepPR, a progressive recovery
technique based on Deep Reinforcement Learning (Deep RL). Our simulation
results indicate that DeepPR can achieve the near-optimal solutions in certain
networks and is more robust to adversarial failures, compared to a baseline
heuristic algorithm.Comment: Technical Report, 12 page
