The EduGIS project aims to introduce secondary school students to GIS. The project
team contains both educational experts and GIS experts. It provides a free website
with geographical information, a viewer and assignments for different levels of
students. The assignments are for individual students or small groups of 2 or 3
students. Originally it was based on a mix of proprietary and open source software.
It was quickly discovered that the original setup could not cope with the traffic
generated by one class, let alone multiple classes at once. The main issue was the
WMS server which could not provide 300 maps per second as was required.
In 2005 Geodan S&R was asked to improve the performance, to reach the goal of 300
requests per second. Also they were asked to improve the manageability of the site.
To reach both the performance goal and improve the manageability it was decided to
replace the entire site with a new setup based solely on open source software. For
the site management Joomla was chosen and for the WMS a combination of UMN Mapserver,
Community Mapbuilder. This did improve the performance a 4 fold but still it did not
reach nearly the goal of 300 requests per second.
It became clear that with the current WMS approach it would not be possible to reach
the performance goal. A more radical approach was needed to improve the performance.
Server-side caching seemed to be the solution but the WMS specifications do not allow
for that. In this presentation the steps taken to improve the performance, while
keeping WMS compatible, will be discussed.