Performance evaluation of HTTPweb servers in embedded systems

Abstract: This Masters Thesis was carried out in cooperation with Syntronic AB. The purpose was to determine what was possible in terms of Hypertext Transfer Protocol (HTTP) server performance on selected hardware platforms for embedded systems. The results should be valuable for those who are about to select a hardware platform for an embedded system that will contain a HTTP server, and the evaluation therefore included load limits, performance characteristics and system resource usage. The required data was gathered with performance measurements, and a pre-study was performed to decide on platforms, functionality and performance parameters to include in the study. Three hardware platforms with different levels of performance - BeagleBoard-xM, STK1000 and Syntronic Midrange - were selected. A simulated web application was used during the tests and a total of five HTTP server software were tested. BeagleBoard-xM with BusyBox httpd had the best overall performance when running the test application. It had a high overload point, low connection durations when not overloaded, and a superior overload behavior. However, Midrange with a modified version of a server made by Stefano Oliveri performed better when not overloaded. STK1000 was far behind the other two platforms in terms of performance. The overload behavior and efficiency of system resource usage differed greatly between the servers. The test results also showed that the performance varied significantly between HTTP server software running on the same hardware platform, and generally the software with limited feature sets performed best.