A Measurement Study of the Interplay Between Application Level Restart and Transport Protocol

摘要

Restart is an application-level mechanism to speed up the completion of tasks that are subject to failures or unpredictable delays. In this paper we investigate if restart can be beneficial for Internet applications. For that reason we conduct and analyze a measurement study for restart applied to HTTP GET over TCP. Since application-level restart and TCP time-out mechanisms may interfere, we discuss in detail the relation between restart and transport protocol. The analysis shows that restart may especially be beneficial in the TCP set-up phase, in essence tuning TCP time-out values for the application at hand. In addition, we discuss the design of and experimentation with a proxy-based restart tool that includes a statistical oracle module to automatically adapt and optimize the restart time.