vivo HTTPDNS End-to-End Integrated Solution: Architecture, Optimizations, and Business Impact

Background and motivation: With the rapid growth of mobile application access, users demand higher quality experiences. DNS hijacking, inaccurate resolution, and slow responses degrade user experience, prompting the adoption of HTTPDNS as a mainstream solution.

Challenges faced: Using HTTPDNS as a backup DNS fails to resolve domain misblocking; businesses lack a unified access scheme, leading to high integration costs; diverse client network frameworks complicate adaptation; commercial HTTPDNS services are expensive; and there is no full-link monitoring to observe client-side DNS resolution in real time.

Solution overview: vivo built an end-to-end HTTPDNS integrated solution comprising four modules: HTTPDNS SDK for client-side resolution and connection optimization; HTTPDNS service端 providing high-performance APIs, caching, and proxy gateway; a unified scheduling gateway for policy distribution and framework adaptation; and full-link monitoring for end-to-end visibility.

SDK optimizations: Domain name resolution was improved through retry, adaptive, and IP priority/fallback strategies; caching evolved from fixed to dynamic and optimistic schemes, cutting resolution latency by over 30%; connection optimization added network diagnosis, speed detection, best‑route selection, HTTP2 long‑connection reuse with active/passive detection and end‑side prediction, QUIC connection racing, and a unified access mechanism via the scheduling gateway and multi‑framework adaptation (OkHttp, Volley, HttpURLConnection, Glide, etc.).

Service端 optimizations: The service端 offers intelligent dispatch based on asynchronous IP probing, multi‑level cache with lazy updates, high‑performance APIs for authentication and query, and a management backend for DNS, system, scheduling, authentication, and access control.

Monitoring capabilities: Full‑link tracking records every stage from DNS resolution to request completion, enabling precise anomaly localization; regional ISP‑level monitoring and early warning allow localized optimization and timely issue detection.

Business impact: The platform now serves over 100 vivo businesses, handling about 1.5 billion DNS resolutions per day. Client‑side average resolution latency dropped from 180 ms to 115 ms (a 36 % reduction). Service端 resolution success rate reached 99.5 % with an average response time of ~4 ms and a cache hit ratio of 90 %. Overall DNS success rate improved from 97 % to 99.85 %, and client access success rate rose from 97 % to 99 %. The system effectively prevented hijacking (e.g., iMusic domain in Feb 2023) and mitigated misblocking incidents (e.g., .com.cn domain in Apr 2023).

Future outlook: vivo will explore multi‑channel acceleration (dual mobile, dual Wi‑Fi, or mobile+Wi‑Fi) and端侧调度 using proximity‑based routing, intelligent addressing, and low‑latency dedicated networks to further enhance user experience.