1.2. A Three-Tier LVS Configuration

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.

A Three-Tier LVS Configuration

A Three-Tier LVS Configuration

Figure 1.2. A Three-Tier LVS Configuration

This configuration is ideal for busy FTP 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.


Note: This documentation is provided {and copyrighted} by Red Hat®, Inc. and is released via the Open Publication License. The copyright holder has added the further requirement that Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copyright holder. The CentOS project redistributes these original works (in their unmodified form) as a reference for CentOS-5 because CentOS-5 is built from publicly available, open source SRPMS. The documentation is unmodified to be compliant with upstream distribution policy. Neither CentOS-5 nor the CentOS Project are in any way affiliated with or sponsored by Red Hat®, Inc.