Experimental Evaluation of an Adaptive Flash Crowd Protection System
نویسندگان
چکیده
Network early warning system (NEWS) is an adaptive flashcrowd protection system. Unlike approaches using manually configured request rate limit, NEWS regulates incoming requests by observing response performance, automatically adapting to changing traffic mixes. We have previously studied NEWS performance through simulation; this paper presents an implementation of NEWS on a Linux-based router. We evaluate this implementation in testbed experiments with HTTP server log recorded during a flash crowd. Our first contribution is to use implementation and testbed experiments to evaluate NEWS performance in a server memory-limited scenario, which was not considered in our previous simulation study. Our results show that NEWS is effective in both networkand server-limited scenarios. Second, we evaluate the run-time cost of NEWS traffic monitoring in practice, and find that it consumes little CPU time and relatively small memory. Finally, we extend core NEWS algorithms to include a simple hot-spot identification function to protect bystander traffic from flash crowds efficiently.
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