Bega High School Work Experience – A Load Balanced Web Server

This week we have been given the opportunity to conduct our work placement for I.T VET at 2pi Software. Within these days we have been able to set up a small web server running an Odroid as the master system, which had a load balancer installed, using Nginx, to evenly spread the traffic from incoming requests.

A load balancer is a device that evenly distributes incoming traffic between nodes. This increases the amount of requests and will increase the reliability of the server, which is critical for a company’s efficiency for their online presence. A company that uses load balancing is Google, which would have a massive load of requests being sent to the servers, which will then have to be evenly distributed across all their servers.

The requests were then distributed across 3 different Raspberry Pi systems, low cost, high availability micro computers that allow users to achieve goals such as learning basic coding to more experienced projects like creating a mini arcade machine.

These were then benchmarked to see how much stress the server will be able to take when under a heavy load of requests. We recorded our results and then compared the data to make sure the nodes were running at the same efficiency.

Also during the week we were given the task of making a MySQL database which was hosted on the Odroid to observe how the web server could handle the load of running a MySQL database with PHP.

Setup

Our setup looks like this:

Results

We ran multiple tests using different types of media, these include:

• Static HTML
• Static HTML with an image
• PHP
• PHP and MySQL

The results we collected are below, where data presented ranges from the 50th to 100th percentile. The number on the right of the percentage indicates the response time in milliseconds.

Odroid w/PHP & MySQL (3 nodes)	Odroid w/ static HTML	Odroid w/ PHP	Odroid w/ image HTML
50%   1510   66%   1546   75%   1563   80%   1573   90%   1597   95%   1619   98%   2139   99%   2387 100%   2690 (longest request)	50%    211   66%    245   75%    301   80%    322   90%    358   95%    394   98%    453   99%    528 100%   1493 (longest	50%    962   66%   1031   75%   1069   80%   1092   90%   1150   95%   1193   98%   1235   99%   1306 100%   2288 (longest request)	50%    214   66%    239   75%    275   80%    304   90%    339   95%    403   98%    651   99%   1201 100%   1273 (longest request)

 

These results show that using more complex web tools will slow down the web server significantly. This is shown in the odroid with PHP & mySQL  which has results that are double of the static HTML.