Tech Erudition

Apache's mod_gzip provides good compression for server output. I just got it working on my server with little bit of tweaking done in the configuration. I was using the debian server.

Install mod_zip if you don't have it already:

apt-get install libapache-mod-gzip

Load the module mod_gzip: (add this line in httpd.conf or modules.conf)
LoadModule gzip_module /usr/lib/apache/1.3/mod_gzip.so
Look at the example http://schroepl.net/projekte/mod_gzip/config.htm configuration file.

Here is the configurtaion I added:

<IfModule mod_gzip.c>
  mod_gzip_on                   Yes
  mod_gzip_can_negotiate        Yes
  mod_gzip_static_suffix        .gz
  AddEncoding              gzip .gz
  mod_gzip_command_version      '/mod_gzip_status'
  mod_gzip_keep_workfiles       No
  mod_gzip_minimum_file_size    500
  mod_gzip_maximum_file_size    500000
  mod_gzip_maximum_inmem_size   60000
  mod_gzip_handle_methods        GET POST

  mod_gzip_item_exclude         reqheader  "User-agent: Mozilla/4.0[678]"

  mod_gzip_item_include         file       \.html$

  mod_gzip_item_include         file       \.js$
  mod_gzip_item_include         file       \.css$

  mod_gzip_item_exclude         mime       ^image/
  mod_gzip_item_include         mime       ^text/

  # This was very important to get things working
  mod_gzip_item_include         uri        .*

  mod_gzip_dechunk              Yes

  LogFormat                     "%h %l %u %t \"%V %r\" %<s %b 
mod_gzip: %{mod_gzip_result}n In:%{mod_gzip_input_size}n -< 
Out:%{mod_gzip_output_size}n = %{mod_gzip_compression_ratio}n 
pct." common_with_mod_gzip_info2

  CustomLog               /var/log/apache/mod_gzip.log common_with_mod_gzip_info2
</IfModule>

I had to add the configuration line mod_gzip_item_include uri .* until then I saw only mod_gzip: DECLINED:EXCLUDED In:0 -< Out:0 = 0 pct. in the mod_zip.log.
Look at http://www.debian-administration.org/articles/31 which reports problem with mod_gzip and mod_ssl, so added this line of configuration as well. Add this only if you enabled ssl access for your server.

<VirtualHost *:443>
  <IfModule mod_ssl.c>
   ...
  </IfModule>

  <IfModule mod_gzip.c>
      mod_gzip_on No
  </IfModule>
</VirtualHost>

NOTE: With Apache2 you can use mod_deflate for the gzip compression. To get more details look at
http://httpd.apache.org/docs/2.0/mod/mod_deflate.html