Application Buffer-Cache Management for Performance: Running the World's Largest MRTG

An operating system’s readahead and buffer-cache behaviors can significantly impact application performance; most often these better performance, but occasionally they worsen it. To avoid unintended I/O latencies, many database systems sidestep these OS features by minimizing or eliminating application file I/O. However, network traffic measurement applications are commonly built instead atop a high-performance file-based database: the Round Robin Database (RRD) Tool. While RRD is successful, experience has led the network operations community to believe that its scalability is limited to tens of thousands of, or perhaps one hundred thousand, RRD files on a single system, keeping it from being used to measure the largest managed networks today. We identify the bottleneck responsible for that experience and present two approaches to overcome it. In this paper, we provide a method and tools to expose the readahead and buffer-cache behaviors that are otherwise hidden from the user. We ...

• Type: Conference
• Year: 2007
• Where: LISA
• Authors: David Plonka, Archit Gupta, Dale Carder
• Keywords: Buffer-cache Behaviors, LISA 2007, Network Traffic Measurement, Operating System, Rrd Files