on our public facing site we want to replace all of its current static with interactive maps.
We hired a consultant to develop those maps using a set of technologies recommended by one of our partner who provided the geographical data.
The technologies used are:
MapInfo
This is the desktop software we use to manipulate offline geographical information, create various layers (countries, cities, rail lines, etc…) and save them *.tab files, the native format for MapInfo.
Map Server
MapServer is the rendering engine we’re using to create images based on the MapInfo data files.
Ka-Map
We used the caching component of Map Server to pre-generate map tiles and store them in the server file systems.
Openlayers
We use the Javascript API Openlayers to interact on the web client with Map Server via the Ka-Map cache.
Mapserver and Ka-Map are installed on a Unix server with the following specifications: …

The development was completed and the map works according to requirements: layers are loaded and assembled properly, and the user can browse the map by panning and zooming in or out.
The problem we’ve encountered is scalability: a stress test with 20 concurrent users failed, causing CPU usage to reach 100% and clogging the bandwidth.
The questions we have for this esteemed forum are the following:
-Is MapServer an appropriate technology to support mapping applications on a public facing website? If not, what alternative technologies can we use?
-Is Ka-Map a suitable caching component for MapServer? Are there better performing caching component available to work with MapServer?
-Is our hosting platform appropriately sized to support MapServer / Ka-Map for use on a public facing website? If not, what would be a suitable hosting environment?
-What areas should we work on to improve the scalability of our hosting platform. Our developer recommended: switching from a Virtual Machine to a dedicated server, implementing fast-cgi for PHP.

Thanks you all for your help in this matter
Best regards
FB