Programmable data plane hardware creates a possibility to solve network-related problems. Ensuring fault tolerance of link failures is a fundamental network issue. Link failure recovery mechanisms are widely used in traditional and software-defined networks. The proactive failure recovery mechanism usually requires a backup path to be installed in the switch in advance. When the link fails, the switch can quickly switch to the backup path to continue sending packets. However, storing a large number of backup paths consumes a lot of switch storage. In this article, we analyze why implementing traditional proactive failure recovery mechanism introduces huge switch storage overhead, and discuss the flexibility and limitations of the programmable data plane. Then, we present P4Neighbor, a proactive link failure recovery framework based on the programmable data plane. P4Neighbor encapsulates backup paths into the header of a packet when a link failed and leverages this information to achieve link failure recovery. By storing only the backup paths of the neighbor switches, P4Neighbor requires little switch storage to store backup paths. Besides, P4Neighbor also takes complex link failure situations into consideration, which makes the network’s fault tolerance slightly increase. Experimental results show that compared with the traditional failure recovery mechanism, P4Neighbor achieves a reduction rate of 57.9%-84.5% in terms of stored switch entries. Meanwhile, P4Neighbor also has a higher failure recovery ratio than traditional proactive link failure recovery mechanisms.

中文翻译：

---

P4Neighbor：使用可编程交换机进行有效的链路故障恢复

可编程数据平面硬件为解决与网络相关的问题提供了可能性。确保链路故障的容错能力是一个基本的网络问题。链路故障恢复机制广泛用于传统和软件定义的网络。主动故障恢复机制通常需要事先在交换机中安装备份路径。当链路出现故障时，交换机可以快速切换到备份路径以继续发送数据包。但是，存储大量备份路径会消耗大量的交换机存储空间。在本文中，我们分析了为什么实施传统的主动故障恢复机制会带来巨大的交换机存储开销，并讨论了可编程数据平面的灵活性和局限性。然后，我们提出P4Neighbor，基于可编程数据平面的主动链路故障恢复框架。当链路发生故障时，P4Neighbor将备份路径封装到数据包的报头中，并利用此信息来实现链路故障恢复。通过仅存储邻居交换机的备份路径，P4Neighbor需要很少的交换机存储来存储备份路径。此外，P4Neighbor还考虑了复杂的链路故障情况，这使得网络的容错能力略有提高。实验结果表明，与传统的故障恢复机制相比，P4Neighbor在存储的交换机条目方面实现了57.9％-84.5％的减少率。同时，P4Neighbor的故障恢复率也高于传统的主动链路故障恢复机制。当链路发生故障时，P4Neighbor将备份路径封装到数据包的报头中，并利用此信息来实现链路故障恢复。通过仅存储邻居交换机的备份路径，P4Neighbor需要很少的交换机存储来存储备份路径。此外，P4Neighbor还考虑了复杂的链路故障情况，这使得网络的容错能力略有提高。实验结果表明，与传统的故障恢复机制相比，P4Neighbor在存储的交换机条目方面实现了57.9％-84.5％的减少率。同时，P4Neighbor的故障恢复率也高于传统的主动链路故障恢复机制。当链路发生故障时，P4Neighbor将备份路径封装到数据包的报头中，并利用此信息来实现链路故障恢复。通过仅存储邻居交换机的备份路径，P4Neighbor需要很少的交换机存储来存储备份路径。此外，P4Neighbor还考虑了复杂的链路故障情况，这使得网络的容错能力略有提高。实验结果表明，与传统的故障恢复机制相比，P4Neighbor在存储的交换机条目方面实现了57.9％-84.5％的减少率。同时，P4Neighbor的故障恢复率也高于传统的主动链路故障恢复机制。通过仅存储邻居交换机的备份路径，P4Neighbor需要很少的交换机存储来存储备份路径。此外，P4Neighbor还考虑了复杂的链路故障情况，这使得网络的容错能力略有提高。实验结果表明，与传统的故障恢复机制相比，P4Neighbor在存储的交换机条目方面实现了57.9％-84.5％的减少率。同时，P4Neighbor的故障恢复率也高于传统的主动链路故障恢复机制。通过仅存储邻居交换机的备份路径，P4Neighbor需要很少的交换机存储来存储备份路径。此外，P4Neighbor还考虑了复杂的链路故障情况，这使得网络的容错能力略有提高。实验结果表明，与传统的故障恢复机制相比，P4Neighbor在存储的交换机条目方面实现了57.9％-84.5％的减少率。同时，P4Neighbor的故障恢复率也高于传统的主动链路故障恢复机制。实验结果表明，与传统的故障恢复机制相比，P4Neighbor在存储的交换机条目方面实现了57.9％-84.5％的减少率。同时，P4Neighbor的故障恢复率也高于传统的主动链路故障恢复机制。实验结果表明，与传统的故障恢复机制相比，P4Neighbor在存储的交换机条目方面实现了57.9％-84.5％的减少率。同时，P4Neighbor的故障恢复率也高于传统的主动链路故障恢复机制。