Managing Edge Resources at Scale: A Peer-to-Peer CDN for On-Demand Video Streaming

The rapid proliferation of video services has created a strong demand for efficient content delivery. Traditional solutions primarily rely on Content Delivery Networks (CDNs), which, while effective, impose substantial bandwidth costs on video providers. To address this challenge, cost-efficient edge resources have emerged as a promising alternative. However, their heterogeneous hardware and inherently limited performance pose significant challenges for practical deployment. In this paper, we present how ByteDance explores the use of these cost-efficient but less performant resources. Specifically, we first present an extensive overview of PCDN (Peer-to-Peer CDN), ByteDance’s alternative delivery network for CDNs. Second, as PCDN encounters speed degradation and resource imbalances after years of deployment, we further introduce PCDN + , the enhanced iteration of PCDN. Specifically, we first propose a joint control protocol. By using de-synchronized probing and proactive retransmission, our protocol significantly improves the performance degradation caused by self-competition and head-of-line blocking (HoL). We then introduce a resource management framework. By integrating a well-designed centralized/decentralized framework, we evolve previous “static” and “uncontrolled” PCDN into a “dynamic” and “controlled” system. The extensive A/B test and real-world deployment have demonstrated that PCDN + 1) provides higher service speed, 2) effectively alleviates overloading issues, 3) significantly improves the utilization of low-cost resources.