From: Bill Kelly <billk@...>
Date: 2003-01-24T07:31:10+09:00
Subject: Re: mod_ruby: what's persistent and what's shared?

Hi,

From: "Ollivier Robert" <roberto@REMOVETHIS.eu.org>
>
> Imagine you do something like this in your httpd.conf
> 
> -=-=-
> RubyRequire common-data
> -=-=-
> 
> and that in common-data.rb you have this:
> 
> -=-=-
> require 'dbi'
> 
> $DB = DBI.connect("dbi:mysql:foodb", "user", "password")
> -=-=-
> 
> Will all instances of httpd share the same $DB ? Remember that it is not
> data created by a script or a .rhtml page, it is data created when you
> start the httpd server...

My guess is that this would be problematic.  Forked children
do inherit copies of the parent's file handles (I'm assuming
a DB connection is at its heart a file handle / socket?)

My guess as to what would happen would be that the child http
processes would indeed probably "share the same $DB", assuming
the http.conf processing happens before the children are forked.

However, I think it would likely be a problem to have the 
child processes all chattering simultaneously at the DB over
the same connection.  I wouldn't expect that to work properly.
(But I don't know how it's implemented, so I could be wrong.)


Regards,

Bill