Evaluating and improving push based video streaming with HTTP/2

Abstract

The sever-initiated push mechanism is one of the most prominent features in the next generation HTTP/2 protocol, having shown its capability on saving network traffic and improving the web page retrieval latency. Our prior work has investigated the server push-based mechanism for HTTP video streaming and proposed a k-push scheme, where the server pushes k video segments following the response to a request. In this study, we further conduct an analysis and evaluation of the k-push scheme in HTTP streaming. Our results uncover that the push mechanism can efficiently increase the network utilization (under certain conditions) compared to regular HTTP streaming. However the results also show that the k-push scheme deteriorates network adaptability and leads to the "over-push" problem, in which the pushed video content waste network resources due to user abandonment behaviors. To overcome these limitations, we propose a new " adaptive-push" scheme, which dynamically adjusts the parameter k to adapt to the runtime environment. To evaluate the performance of adaptive-push, we implemented a prototype system. The experimental results show that compared to k-push, adaptive-push can improve the network adaptability. Furthermore, our real-world trace based simulation results show that adaptive-push can effectively alleviate the over-push problem.