2021/10/27 by Constantin Sander, Leo Blöcher, Klaus Wehrle +1 · 1 voice
Computer Science · #cs.NI
paper · pdf · doi:10.1145/3487552.3487832
HTTP/2 and HTTP/3 avoid concurrent connections but instead multiplex requests over a single connection. Besides enabling new features, this reduces overhead and enables fair bandwidth sharing. Redundant connections should hence be a story of the past with HTTP/2. However, they still exist, potentially hindering innovation and performance. Thus, we measure their spread and analyze their causes in this paper. We find that 36% - 72% of the 6.24M HTTP Archive and 78% of the Alexa Top 100k websites cause Chromium-based webbrowsers to open superfluous connections. We mainly attribute these to domain sharding, despite HTTP/2 efforts to revert it, and DNS load balancing, but also the Fetch Standard.