Improve your Web Application Performance using .htaccess

Submitted by Sudeepg
on Fri, 01/08/2010 - 07:56

File Caching is powerful and is useful for files on web server that do not change. Images, pdf files and other static content can be cached, thus reducing the network traffic between the server and the client.

In this tutorial you'll learn how to do file caching using Apache .htaccess file.

Measure Your Web Performance

There is a great tool: http://www.webpagetest.org/test that you can use to measure your performance. It would suggest your first load time and repeat time view as well along with suggestions.

 

Enabling .htaccess on your Linux server

First step is to check that .htaccess is enabled on your linux server.  If it is not, you would have to find this line in Apache's httpd.conf:

AllowOverride None

Change it to read as follows and restart the server.

AllowOverride All

Making Changes in .htaccess One by One:

1. Keep-Alive:

If you are not using any caching server for files, KeepAlive On helps in delivering all the static files in a single connection. Find your httpd.conf and make KeepAlive On. If you have a static files serving mechanism (like having squid or serving static files through high throughput server like lighttpd), KeepAlive off usually is a positive turn on the performance.

2. ETags:

  You can change all the headers you want, but if the ETag associated with a file is always the same, caching will never work the way you expect. In most situations, you should turn your ETag headers off.

<FilesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|js|css|swf)(\.gz)?$">
Header unset ETag
FileETag None
</FilesMatch>

3.  Expire Header:

We need to expire static files into far-future, since, we don't want them to be called from server again and again on every page load  as follows:

<FilesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|js|css|swf)(\.gz)?$">
Header set Expires "Thu, 31 Dec 20125 10:00:00 GMT"
</FilesMatch>

4. Enable mod_deflate for Apache 2.x

<IfModule mod_deflate.c>

<FilesMatch "\.(jpg|gif|png|js|css|html)$">
SetOutputFilter DEFLATE
</FilesMatch>
</IfModule>

Put the settings in the server configuration instead.

Wed, 06/09/2010 - 03:13 — Anonymous

Good stuff, but you'll want to move all of the settings into the apache configuration (if you can) and turn off AllowOverride.  Having the web server search for, and parse, the .htaccess file(s) on each request is slow and causes extra disk IO.

Nice

Wed, 06/09/2010 - 11:04 — Anonymous

Nice post, but I find with lots of 'how to' posts these days, they are full of 'do this and do that' but without an explanation as to why you should. 

Agree

Wed, 06/09/2010 - 11:47 — Anonymous

I agree with "Nice" mister : you don't give any explanations about what is ETags, Keep-Alive and mod_deflate.

It is obvious for advanced user certainly not for everyone.