----- "Graham Leggett" <[email protected]> wrote:
> The very definition of "tuned" means "tailored for your local setup".
It's actually quite hard to get this thought accross. I think we should
put it in a reboot of the performance ``optimization'' documentation.
> The default httpd configuration works reasonably well out the box. It
>
> is only when your site has special needs that it should start changing
>
> the setup, and the site should understand what their needs are and
> whether it is appropriate to turn it on.
>
> Zooming into mod_deflate, mod_deflate only makes sense if you have the
>
> CPU to support it. If you don't have enough CPU support (think
> virtualised hosts), mod_deflate will be a performance drag, not a
> boost. Typically, you would want to front a mod_deflate with an HTTP
>
> cache, such as mod_cache (or equivalent). Here mod_cache only makes
> sense if you have the disk space to support it, and there is no real
>
> one-size-fits-all cache setup.
We arrive at one of my pet-peeve topic: Sane defaults.
mod_cache's default values for CacheDirLevels and CacheDirLength will
tear your file-system apart. And that is pretty much what:
http://httpd.apache.org/docs/2.2/caching.html says...
> The next problem is that you only want to enable mod_deflate on
> compressible content - that means "not images" for most people, but
> might not be. Again, not every site has the same content, and
> therefore not every site has the same setup for mod_delate.
>
> This said, our default config is 15 years old, and attempts to disable
>
> deflate for browsers that don't support it, like "Netscape 4". Unless
>
> there are modern browsers that have broken protocol support for
> transfer encoding, these obsolete examples need to be removed.
An entirely different topic, but related to your proposal is that
mod_deflate suggests to use a mod_filter based setup, but there's no
example on how to configure that.
(See my attached patch. Then you might understand why ;)
> Regards,
> Graham
> --
Bye,
--
Igor Galić
Tel: +43 (0) 699 122 96 338
Fax: +43(0) 1 91 333 41
Mail: [email protected]
URL: http://brainsware.org/
Index: mod/mod_deflate.xml
===================================================================
--- mod/mod_deflate.xml (revision 949964)
+++ mod/mod_deflate.xml (working copy)
@@ -44,32 +44,20 @@
AddOutputFilterByType DEFLATE text/html text/plain text/xml
</example>
- <p>The following configuration, while resulting in more compressed content,
+ <p>The following configuration, while being the recommended setup using mod_filter,
+ results in more compressed content than the above but
is also much more complicated. Do not use this unless you fully understand
all the configuration details.</p>
<example><title>Compress everything except images</title>
<Location /><br />
<indent>
- # Insert filter<br />
- SetOutputFilter DEFLATE<br />
- <br />
- # Netscape 4.x has some problems...<br />
- BrowserMatch ^Mozilla/4 gzip-only-text/html<br />
- <br />
- # Netscape 4.06-4.08 have some more problems<br />
- BrowserMatch ^Mozilla/4\.0[678] no-gzip<br />
- <br />
- # MSIE masquerades as Netscape, but it is fine<br />
- BrowserMatch \bMSIE !no-gzip !gzip-only-text/html<br />
- # Don't compress images<br />
- SetEnvIfNoCase Request_URI \<br />
- <indent>
- \.(?:gif|jpe?g|png)$ no-gzip dont-vary<br />
- </indent>
- <br />
- # Make sure proxies don't deliver the wrong content<br />
- Header append Vary User-Agent env=!dont-vary<br />
+ # Declare filter, add mod_deflate for all text/* MIME Types<br />
+ FilterDeclare COMPRESS<br />
+ FilterProvider COMPRESS DEFLATE resp=Content-Type $text/<br />
+ FilterChain COMPRESS<br />
+ FilterProtocol COMPRESS change=yes;byteranges=no
+ Header append Vary User-Agent env=!dont-vary<br />
</indent>
</Location>
</example>
