Enabling data compression on an IBM HTTP Server

The Apache mod_deflate module can be used to improve response time in

environments that have low bandwidth and high latency. The Apache mod_deflate
module compresses output from your server before the data is sent to the
client over the network. You can set the compression level to 3 or 6 to improve
response time.

Before you begin
The mod_deflate module is only available in Apache server version 2.0 and higher.
To verify the server version, use the apachectl -V command.

Procedure
1. Stop the server by running the following command:
apachectl stop

2. Create a backup copy of httpd.conf.

3. Open httpd.conf in a text editor.

4. Change the KeepAliveTimeout 10 line to KeepAliveTimeout 60.

5. Uncomment the LoadModule deflate_module modules/mod_deflate.so line. If
you cannot find the LoadModule deflate_module modules/mod_deflate.so line,
in the # Dynamic Shared Object (DSO) Support section, immediately after the #
LoadModule foo_module modules/mod_foo.so comment, add the line for the
module.

6. Locate the section in the file for adding filters. Immediately under the
#AddOutputFilter INCLUDES .shtml comment, add the following lines:
AddOutputFilterByType DEFLATE text/html text/plain text/xmlBrowserMatch
^Mozilla/4 gzip-only-text/html
BrowserMatch ^Mozilla/4 gzip-only-text/html
BrowserMatch ^Mozilla/4\.0[678] no-gzip
BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
#Highest 9 - Lowest 1
DeflateCompressionLevel 3

The compression level is now set to 3, which provides minimal CPU usage and
a decent benefit from the compression. You can also set the compression level
to 6, which provides even more compression benefit with a small CPU
overhead.