Installing and Configuring Apache Toolkit for Serviceguard for Linux

To use the Apache Web Server application in your environment, the Apache web server must be
installed on all cluster nodes configured to run an Apache package. A typical configuration of an
Apache Web Server application is one where one node is configured as a primary node and the
others are configured as standby or secondary nodes. The Apache Web Server application runs on
the primary node and accepts (HTTP/S) requests and serves clients. If the primary node fails, a
standby node takes over the server activities. This take over is seamless and does not interrupt any
of the processes in the environment. For this seamless transition to occur, all configuration
information of all nodes must be identical and all resources must be available to all nodes.
Apache Web Server supports multiple instances of server daemons that are running on a node
simultaneously. For each instance of an Apache Server, an Apache package is created with its own
server root directory, toolkit files and configuration information. Each instance may support one or
more websites, depending on whether or not an instance has been configured to use "virtual hosts".
The server root directory contains the appropriate configuration file that specifies how an Apache
server instance is configured. The Apache configuration directives within this file determine the
location of the log files, web documents, and the domain name address for the specific Apache
server instance.
NOTE: If you have a Red Hat Enterprise Linux system in your environment, then the configuration
file resides in the conf/httpd.conf file in the server root directory. If you have a SUSE Linux
Enterprise Server, the configuration file resides in the httpd.conf in the server root directory.
STORAGE CONFIGURATIONS
You can configure the Apache toolkit using either one of the following storage configuration options:
• Local configuration
In this configuration, place the configuration files and the other website files on a single
node, and replicate them on all other nodes in the cluster.
• Shared configuration
In this configuration, place the configuration files and the other Web site files on a shared
file system. All the nodes in the cluster will access these files from the shared file system.
The following sections discuss these configuration options in detail.
Local Configuration
In a typical local configuration, files are not shared among nodes. Identical copies of the Apache
server configuration file and web documents must reside in exactly the same locations on each
node. If you update the information in a file on a single node, you must update the files on all other
nodes with the same changes. The administrator needs to ensure that all the files on all the nodes
are identical and always up-to-date. This local configuration setup is more useful in scenarios where
the information on the Web page is static and does not change very often.
Shared Configuration
In a typical shared configuration, the document root directories reside on a shared file system. You
can also place the server root directory in this shared file system. However, this is optional. By
placing the files and directories on a shared file system, the information automatically becomes
accessible to all the nodes in the cluster. You need not have to maintain copies of all the files and
directories on every node in the cluster. However, you must ensure that the mount point of the
shared file system is identical across all Apache package nodes.
HP recommends that you use the shared configuration option for configuring this toolkit because
you do not have to maintain identical copies of the files and directories on all nodes. In addition, with
this option, all information is automatically accessible to all nodes.