Database servers connected as a cluster to the main server
There could be three database servers connected as a cluster to the main server to provide better connectivity and services.
The basic software required for the server should be capable of handling NCSA HTTPd and CERN HTTPd. Products such as Netscape Enterprise Server, MS IIS, FastTrack Server, etc. are well known products in this line. They are available for a variety of OS such as UNIX, Windows NT, Mac OS, etc.