Installation guide

Example of Setting Up Apache HTTP Server

This appendix provides an example of setting up a highly available Apache HT T P Server on a Red Hat

Cluster. T he example describes how to set up a service to fail over an Apache HT T P Server. Variables

in the example apply to this example only; they are provided to assist setting up a service that suits your

requirements.

Note

This example uses the Cluster Configuration Tool (system -config-cluster). You can

use comparable Conga functions to make an Apache HTTP Server highly available on a Red Hat

Cluster.

A.1. Apache HTTP Server Setup Overview

First, configure Apache HT T P Server on all nodes in the cluster. If using a failover domain , assign the

service to all cluster nodes configured to run the Apache HTTP Server. Refer to Section 5.6,

“Configuring a Failover Domain” for instructions. T he cluster software ensures that only one cluster

system runs the Apache HT T P Server at one time. T he example configuration consists of installing the

httpd RPM package on all cluster nodes (or on nodes in the failover domain, if used) and configuring a

shared GFS shared resource for the Web content.

When installing the Apache HTTP Server on the cluster systems, run the following command to ensure

that the cluster nodes do not automatically start the service when the system boots:

# chkconfig --del httpd

Rather than having the system init scripts spawn the httpd daemon, the cluster infrastructure initializes

the service on the active cluster node. T his ensures that the corresponding IP address and file system

mounts are active on only one cluster node at a time.

When adding an httpd service, a floating IP address must be assigned to the service so that the IP

address will transfer from one cluster node to another in the event of failover or service relocation. The

cluster infrastructure binds this IP address to the network interface on the cluster system that is

currently running the Apache HTT P Server. T his IP address ensures that the cluster node running

httpd is transparent to the clients accessing the service.

The file systems that contain the Web content cannot be automatically mounted on the shared storage

resource when the cluster nodes boot. Instead, the cluster software must mount and unmount the file

system as the httpd service is started and stopped. T his prevents the cluster systems from accessing

the same data simultaneously, which may result in data corruption. T herefore, do not include the file

systems in the /etc/fstab file.

A.2. Configuring Shared Storage

To set up the shared file system resource, perform the following tasks as root on one cluster system:

1. On one cluster node, use the interactive parted utility to create a partition to use for the

document root directory. Note that it is possible to create multiple document root directories on

different disk partitions.

2. Use the mkfs command to create an ext3 file system on the partition you created in the previous

Example of Setting Up Apache HTTP Server