Virtual Servers

The new web platform will make use of server virtualization that offers the following benefits.

Increased Availability
Virtual servers can be moved if physical servers break. It is possible to control this live migration automatically so that hardware problems are less likely to interrupt operation:

The image above (courtesy of RedHat Magazine, distributed under the terms of Creative Commons Attribution-Noncommercial 2.0) illustrates what happens when a server fails in a server virtualization environment. Normally if the server hosting websites A and B were to fail, the websites would be unavailable until the server was brought back online. With virtualization, live migration to different physical servers occurs when physical failure is detected.

Saves Time and Scales Easily
New virtual web servers can be brought up quickly and fewer physical servers need to be purchased because resources can be shared within a cluster. If more physical servers become necessary, blade servers allow a new physical server to be quickly added so that its memory and CPU can increase the resources of the cluster pool.

Less Energy Consumption
Physical servers can be turned off during low demand to save electricity. Blade servers with software power management offer the option of timing based on cluster need. E.g. it might only be necessary to run four servers during a certain time of the day but an additional two servers can be automatically powered on to meet demand as required.

Web Applications

The new web platform will host the following web-based applications:

Server Software

The web platform will run the following server-based software:
  • Apache 2.x
  • MySQL 5.x
  • Perl 5.x
  • PHP 5.x
  • Redhat Enterprise Linux 5, Advanced Platform

Server Hardware

The web platform will be built on the following hardware:
  • A cluster of six blade servers distributed between the AEC and Pardee data centers running virtualization software. All web servers will exist virtually in this environment.
  • Two Storage Area Networks, one in AEC, one in Pardee Hall, with fiber connections to each server and a Global File System to share storage between servers.
  • Two MySQL servers, one in AEC, one in Pardee Hall, with binary data replication syncing the two.

Related Technical Information

4/14/09