From: Jim Freeze <jim@...>
Date: 2002-04-08T12:06:57+09:00
Subject: Re: ModRUBY question

On Sun, Apr 07, 2002 at 07:55:56PM -0700, Sean Chittenden wrote:
> > I still can't figure out what you mean here:
> > > In effect, there is more than one instance of the
> > > interpreter per mod_ruby instance, but there is only one interpreter
> > > per request.  :~) 
> > 
> > 
> > A clarification would be appreciated.
> 
> MM.... how about this (little ASCII art):
> 
> 
> 
> /--------| 80/tcp |---\
> |                     |
> | /---------------\   | The parent apache process is the only apache
> | | Parent Apache |   | process that listens on port 80 (or any port
> | |  Process      |   | that you tell apache to listen on).
> | \---------------/   |
> |          |          |
> |         /|\         | Apache passes the file descriptor of incoming
> |        //|\\        | requests to an already forked child.
> |       ///|\\\       |
> |      ////|\\\\      |
> |     /////|\\\\\     |
> | /~~~~~~~~~~~~~~~~~\ | An unknown (configurable w/in certain bounds)
> | ~ Multipl child   ~ | number of children serve requests and send
> | ~  processes      ~ | data to clients.
> | \~~~~~~~~~~~~~~~~~/ |
> |                     |
> \---------------------/
> 
> So when you request a page from a webserver, you can get any one of
> potentially hundreds of webservers (5-1024) on my boxen, though
> typically it's capped at 150.  

Yes, I understand all of the above. Very basic stuff.

> Anyway, with the above diagram, you
> should be able to see that you can have your request served by
> possibly many apache processes, 

Wouldn't it be more accurate to say that your request may be
served by 'one' of possibly many apache processes? That is,
a request is served by a single process, not by one or more processes.

> each apache process has its own interpreter.  
  What is this ------------------------^

> Under mod_ruby, one apache process = one Ruby interpreter.

 Ok, so each apache process will have an associated ruby process (not mod_ruby)?


> 
> If you're shaky up to this point, don't read on.  :~) The reason I
> would say that there is only one mod_ruby instance is because mod_ruby
> behaves the same on all Apache processes in the diagram above.  -sc

 (I'm not trying to be difficult here, but) so mod_ruby is an application
  with a single process running on a server and is used by all of the
  apache processes?

Thanks and Cheers
-- 
Jim Freeze
If only I had something clever to say for my comment...
~