[WEB400] Hint: Improve apache performance with mod_deflate

[David Gibbs <david@xxxxxxxxxxxx>]

Folks:

I just ran across a way to improve web page download speed using 
compression ... thought I'd share it with you. :)

Basically, you have to enable gzip compression on your text pages. 
Since most web editors add a lot of whitespace, and web pages are a lot 
of text (which is usually very compressible), using gzip compression can 
improve the performance by reducing the amount of data the web browser 
must download.

You only want to apply gzip compression to text transfers ... as 
graphics are usually already compressed and gzip just wastes time doing 
nothing.

Here's how you do it ...

Add the following to the global section of your apache configuration:

LoadModule deflate_module /QSYS.LIB/QHTTPSVR.LIB/QZSRCORE.SRVPGM

Then, in the content specific sections (virtual hosts, locations, 
directories, etc, I think you can also set this globally):

AddOutputFilterByType DEFLATE text/html text/plain text/xml

Then stop & start your server.  If you look at your log files, you 
should notice that when a page is downloaded, the amount of data 
transfered is smaller than the actual page size.

Documentation for mod_deflate can be found at:
http://httpd.apache.org/docs-2.0/mod/mod_deflate.html

I'm not 100% sure that mod_deflate is shipped with the server normally 
... check out this for more information:
http://tinyurl.com/3c3nv or 
http://publib-b.boulder.ibm.com/Redbooks.nsf/RedbookAbstracts/tips0288.html?Open
You might need to order a PTF.

If you want to check to see if the gzip compression is actually working, 
try this online tool:
http://leknor.com/code/gziped.php

david