Performance evaluation of a portable single-board computer as a 3-tiered LAMP stack under 32-bit and 64-bit Operating Systems

Abstract

In this work, we propose a 3-tiered architecture running the Linux, Apache/Nginx, MariaDB and PHP (LAMP) stack on a 64-bit Operating System (OS) and a Solid-State Disk inside a Raspberry Pi (RPI) for performance evaluation. The relative response time and Application Performance Index (Apdex) for a 32-bit OS were measured and compared against an increasing load with Moodle as the application. Our choice of Moodle as a testbed is influenced by, amongst others, the 3-tiered LAMP architecture of MoodleBox as an image for the RPI, the relatively large database underlying Moodle (with more than 200 relational tables), the convenience offered by its sample tests courses and test plans in developing performance tests. Moodle can be easily substituted from the environment to create portable LAMP-based applications. The relative response time improved by 11.9 s for a medium-sized course with 100 users with the upgrades. The Apdex showed that the CPU of the RPI was the limiting factor that prevented the web application from scaling to beyond 40 users for medium-sized courses. This work's methodology, tests, and findings are important to administrators, educators, and users in general involved in capacity planning for the use of portable applications running under the LAMP stack. A ready for use image of the portable 64-bit LAMP stack is available for download. For a video summary of this paper, please visit https://rpi64box.com.

Keywords

• Web server
• Raspberry Pi
• Portable
• 3-tier
• Performance
• 64-bit