Client behavior and feed characteristics of RSS, a publish-subscribe system for web micronews

Abstract

While publish-subscribe systems have attracted much re-search interest since the last decade, few established bench-marks have emerged, and there has been little characteri-zation of how publish-subscribe systems are used in prac-tice. This paper examines RSS, a newly emerging, widely used publish-subscribe system for Web micronews. Based on a trace study spanning 45 days at a medium-size aca-demic department and periodic polling of approximately 100,000 RSS feeds, we extract characteristics of RSS con-tent and usage. We find that RSS workload resembles the Web in content size and popularity; feeds are typically small (less than 10KB), albeit with a heavy tail, and feed popularity follows a power law distribution. The update rate of RSS feeds is widely distributed; 55 % of RSS feeds are updated hourly, while 25 % show no updates for sev-eral days. And, only small portions of RSS content typ-ically change during an update; 64 % of updates involve less than three lines of the RSS content. Overall, this pa-per presents an analysis of RSS, the first widely deployed publish-subscribe system, and provides insights for the de-sign of next generation publish-subscribe systems. 1