Two PHP’s are better than one

So I’m sitting there, one warm
afternoon, thinking up ways to improve upon the software I’ve been
developing over the last year or so. Of course, speed improvements
are always sought after, as well as improved simplicity of design.
When those go hand in hand, you are golden.

With PHP it is possible to accomplish both in many
ways. One method I have used to great success is to createC modules
to expand the core functionality of PHP. Convert a couple of those
frustratingly slow, but critical, routines into C and you will very
likely see a major performance boost, not to mention a pat on the
back from your boss, accolades from PHP development groups, and
serious respect from your fellow developers. This of course is
assuming you don’t bomb the compilation of PHP and shut down 30 of
your e-commerce sites while you scramble to undo the mess on the
server. That usually gets you a completely different reaction from
you boss.

The solution my friends, is
to not work on the same PHP build that is currently interpreting the
myriad of websites requiring immediate services. “I know that!”, you
say, “But how can you run multiple builds of PHP on the same server
and have some sites be served by one of the PHP builds, while the
other (the test one) is served by another PHP build all while using
one instance of Apache?” Well my long-winded,
run-on-sentence-speaking friend?? here is how you do it.

First, the context: I’m currently working with a
FreeBSD system, utilizing Apache 1.3 for web services, and PHP 4.2.2.
I haven’t tested this out on Linux or Windows, but I do believe that
any Unix flavor should be fine. The main key is Apache, or rather
the configuration file: httpd.conf

Step One: Organization

For simplicity’s sake, I’m
going to recommend that you organize you system in such a way that
each domain you are hosting has it’s own PHP directory located below
the document root (like cgi-bin). This directory is going to contain
a link to the correct build of PHP for the site.

So here is the directory structure I am going to
use:

/www/clients/myEcommerceSite	This is the root of the Ecommerce site
/htdocs	The document root directory
/php	The php compiler (and source) directory
/images	The images directory (obviously)

Create the same
structure in your test site directory. I would also suggest thatyou
create a directory somewhere else on the server to contain the actual
PHPbuild. You could place the builds in the php folder for each
site, but it is muchmore efficient (should you want multiple sites
to use the same php build) to havea single location, and then simply
link to the correct build inside the php directory.