.htaccess Apache and performance

[ASTRAPI]

Hi

Many users are using .htaccess files with some rules inside and they try to get high performance.

Others are trying to adjust .htaccess files on Nginx web servers...

Well .htaccess is killing your performance what ever rules are you using and Nginx is NOT read that files at all !

.htaccess to work Apache needs to check EVERY directory in the requested path for the existence of a .htaccess file and if it exists it reads EVERY one of them and parses it. This happens for EVERY request. Remember that the second you change that file, it’s effective. This is because Apache reads it every time.

Numbers

http://example.com/site/files/images/layout/header.png

Let’s say we’re not doing any funky aliasing and the file system looks like the path. This covers most of the sites out there. There is the / directory, then site/, files/, images/, and layout/. This amounts to 5 directories that could have a .htaccess file. Let’s say you added a .htaccess in /, files/ and images/. That’s three .htaccess files. That’s pretty typical.

Now the numbers, that’s 6 file system stats and 4 file system reads. Including one for the requested file. This happens for every read. We’ll ignore parsing time because both NGINX and Apache need to do this and we’ll consider the difference in time for this negligible.

Requests / Hour	NGINX FS Stats	NGINX FS Reads	Apache FD Stats	Apache FS Reads	Comment
1	1	1	6	4	Single Request [Pretty much no load]
10	10	10	60	40	Ten Requests [Pretty much no load]
3,600	3,600	3,600	21,600	14,400	1 req/sec [Very low load]
144,000	144,000	144,000	864,000	576,000	40 req/sec [Moderate traffic - nothing very large]
324,000	324,000	324,000	1,944,00	1,296,000	90 req/sec [Higher traffic site - not massive]
576,000	576,000	576,000	3,456,000	2,304,000	160 req/sec [Pretty high traffic - still not massive though]

More Numbers

The default for Apache is to use AllowOverride All. Let’s look at this for a Drupal website. One image for the theme. If you’re website DocRoot is at /var/www/drupal6/ then we just added more file system stats. This adds 3 stats per request. This is an incredibly common Apache/Drupal setup. It’s the end result of countless guides out there.

/var/www/drupal6/sites/example.com/themes/yourtheme/images/layout/header.png

Two .htaccess files will be in this path unless you create your own. I’ll be assuming you added one in /var/www/ because this is common.

Requests / Hour	NGINX FS Stats	NGINX FS Reads	Apache FD Stats	Apache FS Reads	Comment
144,000	144,000	144,000	1,296,000	576,000	40 req/sec
324,000	324,000	324,000	2,916,000	1,296,000	90 req/sec
576,000	576,000	576,000	51,840,000	2,304,000	160 req/sec

Conclusion

Stop using .htaccess. It’s horrible for performance. NGINX is designed to be efficient.