A QoE Perspective on HTTP/2 Server Push

Abstract

HTTP/2 was recently standardized to optimize the Web by promising faster Page Load Times (PLT) as compared to the widely deployed HTTP/1.1. One promising feature is HTTP/2 server push, which turns the former pull-only into a push-enabled Web. By enabling servers to preemptively push resources to the clients without explicit request, it promises further improvements of the overall PLT. Despite this potential, it remains unknown if server push can indeed yield human perceivable improvements. In this paper, we address this open question by assessing server push in both i) a laboratory and ii) a crowdsourcing study. Our study assesses the question if server push can lead to perceivable faster PLTs as compared to HTTP/1.1 and HTTP/2 without push. We base this study on a set of 28 push-enabled real-word websites selected in an Internet-wide measurement. Our results reveal that our subjects are able to perceive utilization of server push. However, its usage does not necessarily accomplish perceived PLT improvements and can sometimes even be noticeably detrimental.