In this paper, we design and implement a distributed network virtualization hypervisor (NVH) system, namely, DPVisor, which can provide superior network programmability based on protocol-oblivious forwarding to realize highly-available, scalable, and protocol-independent virtual software-defined network slicing. The experimental comparisons indicate that DPVisor achieves comparable performance as ONVisor (i.e., an OpenFlow-based ONOS benchmark), in terms of the message processing latency, message processing throughput, and failure recovery time. Moreover, to optimize the performance of the distributed NVH systems, we carefully adjust the consistency model used in the state synchronization of NVH instances and propose a local cache-based scheme to balance the tradeoff between the consistency and availability of network status. Our experimental results confirm that the message processing throughput of the distributed NVH systems can be greatly improved (i.e., for both DPVisor and ONVisor), while the data consistency among NVH instances is still maintained well.INDEX TERMS Software-defined networking (SDN), network virtualization, distributed network hypervisor, consistency model, protocol-oblivious forwarding (POF).