一、安装
http://www.hyperspacecommunications.com/products/mod_gzip.html
页面上有 mod_gzip 的二进制码版本和源码下载。
使用前者的话，直接把文件拷贝到Apache Home 的libexec目录中即可。
下载 mod_gzip.c 后，如果你的Apache用 DSO 模式安装的话，安装：
# /www/bin/apxs -i -a -c mod_gzip.c

二、配置
把配置信息加入到httpd.conf：

# mod_gzip 配置
LoadModule gzip_module libexec/mod_gzip.so
AddModule mod_gzip.c

mod_gzip_on Yes
mod_gzip_minimum_file_size 1002
mod_gzip_maximum_file_size 0
mod_gzip_maximum_inmem_size 60000
mod_gzip_item_include mime "application/x-httpd-php"
mod_gzip_item_include mime "text/*"
# 压缩 Zope 的内容：
mod_gzip_item_include file "[^.]*$"
mod_gzip_item_include mime "httpd/unix-directory"
mod_gzip_dechunk Yes
mod_gzip_temp_dir "/tmp"
mod_gzip_keep_workfiles No
mod_gzip_item_include file ".php$"
mod_gzip_item_include file ".txt$"
mod_gzip_item_include file ".html$"
mod_gzip_item_exclude file ".css$"
mod_gzip_item_exclude file ".js$"

添加下面的行：
LogFormat "%h %l %u %t "%r" %>s %b "%{Referer}i" "%{User-Agent}i" mod_gzip: %{mod_gzip_compression_ratio}npct." mod_gzip

把对应虚拟主机配置中的日志文件参数修改为 mod_gzip。

三、压缩效果
日志文件：
61.169.41.13 - - [02/Mar/2002:01:24:29 -0500] "GET /pipermail/freelamp/2002-March/000026.html HTTP/1.1" 200 72848 "http://www.freelamp.com/pipermail/freelamp/2002-March/subject.html" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461; NetCaptor 6.5.0)" mod_gzip: 54pct.
61.169.41.13 - - [02/Mar/2002:01:24:52 -0500] "GET /new/publish/1003233602/index_html HTTP/1.1" 200 4304 "http://www.freelamp.com/new/publish/search?subject=Zope&op=articles" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461; NetCaptor 6.5.0)" mod_gzip: 65pct.
61.169.41.13 - - [02/Mar/2002:01:24:53 -0500] "GET /new/publish/global_css HTTP/1.1" 200 629 "http://www.freelamp.com/new/publish/1003233602/index_html" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461; NetCaptor 6.5.0)" mod_gzip: 73pct.
61.169.41.13 - - [02/Mar/2002:01:24:54 -0500] "GET /new/publish/Images/sitetitle_img HTTP/1.1" 304 0 "http://www.freelamp.com/new/publish/1003233602/index_html" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461; NetCaptor 6.5.0)" mod_gzip: 0pct.
61.169.41.13 - - [02/Mar/2002:01:26:21 -0500] "GET /new/publish/index_html HTTP/1.1" 200 7317 "http://www.freelamp.com/new/publish/1003233602/index_html" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461; NetCaptor 6.5.0)" mod_gzip: 80pct.
61.169.41.13 - - [02/Mar/2002:01:26:22 -0500] "GET /new/publish/global_css HTTP/1.1" 200 629 "http://www.freelamp.com/new/publish/index_html" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461; NetCaptor 6.5.0)" mod_gzip: 73pct.
61.169.41.13 - - [02/Mar/2002:01:26:24 -0500] "GET /new/publish/TopicImages/Tutorial HTTP/1.1" 304 0 "http://www.freelamp.com/new/publish/index_html" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461; NetCaptor 6.5.0)" mod_gzip: 0pct.
61.169.41.13 - - [02/Mar/2002:01:26:24 -0500] "GET /new/publish/LinkImages/jsp001_img HTTP/1.1" 304 0 "http://www.freelamp.com/new/publish/index_html" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Q312461; NetCaptor 6.5.0)" mod_gzip: 0pct.

可以看到mod_gzip 已经对.html和那些没有点的文件作了压缩，压缩率达到了70-80%。
但是，mod_gzip没有对图片文件作压缩。

灵活应用mod_gzip和缓冲工具等，可以降低带宽利用，提升访问性能与用户体验。