[Envolution-devel] Apache2 and mod_deflate

[Scott K. <sc...@ki...>]

You may or may not know that I have advocated using mod_gzip on apache
servers to compress html and php on the fly to increase perfomance and
page load times.

Since Apache2 there has not been a reliable mod_gzip that is compatible
(one is in the works though)

But for those using Apache2 there is a reliable alternative.

I am a linux advocate so I don't have explanations or examples for
windows users. Sorry!

To setup a linux machine to gzip html and php (you don't ever want to
gzip images) you can follow my example.

This example uses Red Hat Linux 9 (shrike)

First: edit /etc/mime.typrd and add:

application/x-httpd-php         php

Next:

Add this to your /etc/httpd/conf/httpd.conf file:

LoadModule deflate_module modules/mod_deflate.so

Under the section where the modules are actually loaded! 

(This will only work if you actually have this module located in
/etc/httpd/modules...if not you will need to recompile apache with the 

./configure --enable-modules=all --enable-mods-shared=all
--enable-deflate

switch)

Next scroll down a little farther in your httpd.conf file and add these
lines somewhere after the AddHandler type-map var entry is where I have
mine:

<IfModule mod_deflate.c>
SetEnv gzip-only-text/html 1
SetOutputFilter DEFLATE
</IfModule>
                                                                                                                             
SetOutputFilter DEFLATE

DeflateFilterNote ratio
SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary

SetEnvIfNoCase Request_URI \.(?:exe|t?gz|zip|bz2|sit|rar)$ no-gzip
dont-vary

SetEnvIfNoCase Request_URI \.pdf$ no-gzip dont-vary

DeflateMemLevel 9

AddOutputFilterByType DEFLATE text/html application/x-httpd-php

BrowserMatch ^Mozilla/4 gzip-only-text/html

BrowserMatch \bMSIE !no-gzip !gzip-only-text/html

Header append Vary User-Agent env=!dont-vary

(I've put blank lines in between each entry because the second line
starting with SetEnvIfNoCase should not be wrapped, it's supposed tobe
on 1 line and my mailer may wrap it)

Now save your httpd.conf file and restart apache and your webserver will
automatically gzip all php and html files.

NOTE: This method is much more efficient than PHP's built in
ob_gzhandler so if you have any modules that have this hardcoded you
will need to remove that or disable this option in your php.imi file.
mod_deflate does ther gzipping much more efficiently and offers better
performance.

The DeflateMemLevel 9 is the maximum compression for mod_deflate and you
can specify any interval from 1-9 to adjust for best performance and
speed for your server. 6 is usually considered the best in terms of
performance versus compression level.

Despite the fact that the compression algorithm is not as effective as
the one found in mod_gzip, using mod_deflate for Apache 2.0.x is still a
quick and effective way to decrease the size of the files that sent to
clients. Anything that can produce between 50% and 80% in bandwidth
savings with so little effort should definitely be considered for any
and all Apache 2.0.x deployments wishing to use the default Apache
codebase. Once a stable mod_gzip is out for Apache2 I will update the
list and create RPM's if nessessary.

Enjoy!

Zoom

BTW: You can test you server to make sure it is actually gzipping no
matter whether you use mod_gzip or mod_deflate by visiting
http://leknor.com/code/gziped.php and typing in your server URL. To
check if php is being gzipped make sure to use a URL to a php file such
as http://yoursite/index.php