• warning: DOMXPath::query(): Invalid expression in /var/www/ictedge/sites/all/modules/print/lib/dompdf-0.5.1/include/stylesheet.cls.php on line 573.
  • warning: DOMXPath::query(): Invalid expression in /var/www/ictedge/sites/all/modules/print/lib/dompdf-0.5.1/include/stylesheet.cls.php on line 573.
  • warning: Invalid argument supplied for foreach() in /var/www/ictedge/sites/all/modules/print/lib/dompdf-0.5.1/include/stylesheet.cls.php on line 575.

Server Hardware Infrastructure

Submitted by ckelley on Wed, 12/30/2009 - 16:17

For the server-based Zcore implementation called ZEPRS, we built a data center in Lusaka, Zambia's capital.

Specs:

  • 3 Dell PowerEdge servers (web app, database, mail server) loaded w/ CentOs 4, a Red Hat Enterprise distribution. External storage unit and backup unit.
  • Using Cyrus/Postfix/Squirrelmail for mail server/webmail.
  • Mysql 5 database.
  • All 24 clinics in Lusaka are connected via a wireless network we deployed.

When we launched ZEPRS, we already had applications running on Apache, which is a basic (but very good) web server. It operates on port 80 normally. Zeprs is developed in java and runs on tomcat web app server. It can run on port 80, but you cannot have 2 services running on the same port. So, we use a sort of "pass through" functionality provided by the AJP Conector to let apache server on port 80 pass requests for /zeprs to the Tomcat server at port 8080. This is configured in the following files:

  • /etc/httpd/conf/workers.properties (apache config)
  • /usr/local/tomcat5/conf/server.xml (tomcat config)

The ZEPRS project tested running in "standalone" or "offline " mode at installations that were experiencing poor network connectivity. Data collected at the test sites would be periodically synchronised with the master server. At the test sites, the ZEPRS application ran on a typical office PC (Dell Optiplex) purchased in 2003/2004, fitted w/ 1GB RAM and running Windows XP Professional. These local "servers" were setup with the following software:

  • Java JRE 1.5
  • Apache Tomcat 5.5
  • MySQL 5.0
  • ZEPRS web app

A local technician performed the installation using a command shell script that automated most of the installation tasks.