Installation guide

However, this type of data synchronization does not optimally function if the configuration is overloaded
with users constantly uploading files or issuing database transactions. For a configuration with a high
load, a three-tier topology is the ideal solution.
1.2. A Three-Tier LVS Configuration
Figure 1.2, “A Three-Tier LVS Configuration” shows a typical three-tier LVS topology. In this example, the
active LVS router routes the requests from the Internet to the pool of real servers. Each of the real
servers then accesses a shared data source over the network.
Figure 1.2. A T hree-T ier LVS Configuration
This configuration is ideal for busy FT P servers, where accessible data is stored on a central, highly
available server and accessed by each real server via an exported NFS directory or Samba share. This
topology is also recommended for websites that access a central, highly available database for
transactions. Additionally, using an active-active configuration with Red Hat Cluster Manager,
administrators can configure one high-availability cluster to serve both of these roles simultaneously.
The third tier in the above example does not have to use Red Hat Cluster Manager, but failing to use a
highly available solution would introduce a critical single point of failure.
Chapter 1. Linux Virtual Server Overview
11