This is part of The Pile, a partial archive of some open source mailing lists and newsgroups.
To: modperl@apache.org
From: Brian Ferris <bdferris@unity.ncsu.edu>
Subject: Dynamic loading of development libraries
Date: Sat, 3 Mar 2001 12:30:06 -0500 (EST)
I'm currently a developer for an on-line publication using
Apache / mod_perl / Mason. We currently have about six
developers working on the project and I have been running
into problems with concurrent work on the Perl libraries
that power our site.
We use CVS to manage revisions, but the only way for a
developer to see if their code is working is to run it on
our webserver. However, mod_perl's very purpose is to keep
one copy of your modules loaded from the start. StatINC
addresses this problem to a certain extent, but it fails
when you have multiple versions of a Perl module that you
want to load depending on which user is requesting.
I sort of got around this by modifying my Mason handler to
examine the requested URI ( ex. /dev/user_name/blah.html )
and loading the appropriate module for that user.
Basically, this involved modifying the @INC paths in the
handler, requiring the modules, and then calling the StatINC
handler sub to reload any modified modules. This sort of
screams hack and it never worked that well. Processes would
load the proper module for one user, and then use that same
module to serve another user who was looking for his own
modules. Chaos ensued...
I have a few ideas as to what I should try next. Perhaps
limiting RequestsPerChild to 1, such that libraries don't
get reused? I don't know what the ramifications of this
are.
Short of running a webserver for each user (a bad solution
in my opinion) does anyone have ideas?
===
To: Brian Ferris <bdferris@unity.ncsu.edu>
From: Stas Bekman <stas@stason.org>
Subject: Re: Dynamic loading of development libraries
Date: Sun, 4 Mar 2001 02:00:53 +0800 (SGT)
On Sat, 3 Mar 2001, Brian Ferris wrote:
> I'm currently a developer for an on-line publication using Apache /
> mod_perl / Mason. We currently have about six developers working on the
> project and I have been running into problems with concurrent work on the
> Perl libraries that power our site.
>
> We use CVS to manage revisions, but the only way for a developer to see if
> their code is working is to run it on our webserver. However, mod_perl's
> very purpose is to keep one copy of your modules loaded from the
> start. StatINC addresses this problem to a certain extent, but it fails
> when you have multiple versions of a Perl module that you want to load
> depending on which user is requesting.
See Apache::PerlVINC
It's also covered in the guide
===
To: modperl@apache.org
From: Steven Lembark <lembark@wrkhors.com>
Subject: Re: Dynamic loading of development libraries
Date: Sat, 03 Mar 2001 12:33:12 -0600
> I'm currently a developer for an on-line publication using Apache /
> mod_perl / Mason. We currently have about six developers working on the
> project and I have been running into problems with concurrent work on the
> Perl libraries that power our site.
>
> We use CVS to manage revisions, but the only way for a developer to see if
> their code is working is to run it on our webserver. However, mod_perl's
> very purpose is to keep one copy of your modules loaded from the
> start. StatINC addresses this problem to a certain extent, but it fails
> when you have multiple versions of a Perl module that you want to load
> depending on which user is requesting.
>
> I sort of got around this by modifying my Mason handler to examine the
> requested URI ( ex. /dev/user_name/blah.html ) and loading the appropriate
> module for that user. Basically, this involved modifying the @INC
> paths in the handler, requiring the modules, and then calling
> the StatINC handler sub to reload any modified modules. This sort
> of screams hack and it never worked that well. Processes would
> load the proper module for one user, and then use that same module
> to serve another user who was looking for his own modules. Chaos
> ensued...
>
> I have a few ideas as to what I should try next. Perhaps limiting
> RequestsPerChild to 1, such that libraries don't get reused? I don't know
> what the ramifications of this are.
>
> Short of running a webserver for each user (a bad solution in my
> opinion) does anyone have ideas?
>
you can update your httpd.conf to vary the port number based on
who is starting the thing. this gives you something like:
<perl>
...
%portlist = qw( jow 8081 bloe 8082 john 8083 doe 8084 );
$Port = $portlist{$ENV{LOGNAME}} or die "no port for $ENV{$LOGNAME}";
to check out a new version just bounce your copy of the
server and keep going. normal cycle looks something like
cvs -q update -d;
bounce;
try it, edit thing, keep going. if you reach a point where
something works use cvs commit.
===
To: Brian Ferris <bdferris@unity.ncsu.edu>
From: "Philippe M \. Chiasson" <gozer@cpan.org>
Subject: Re: Dynamic loading of development libraries
Date: Sat, 3 Mar 2001 15:59:32 -0500
There are 2 realistic solutions to your problem :
1. run a web server for each user ( a good solution in my opinion )
2. wait for Doug to finish up mod_perl 2.0
I know the problem you have with development + mod_perl, and honestly, these
are the only avaliable options.
===
To: "Philippe M . Chiasson" <gozer@cpan.org>,
From: "Stathy Touloumis" <stathy.touloumis@edventions.com>
Subject: RE: Dynamic loading of development libraries
Date: Sat, 3 Mar 2001 15:47:18 -0600
Or set MaxClients to 1 if you do not have too many developers and/or your
development server doesn't suck ; )
===
To: "'Brian Ferris'" <bdferris@unity.ncsu.edu>,
modperl@apache.org
From: Steven Vetzal <steve@dabax.com>
Subject: RE: Dynamic loading of development libraries
Date: Sat, 3 Mar 2001 17:30:08 -0500
Hi Brian,
I've been over this a few times in our environment - and the best solution
I've been able to come up with has been to run multiple Apache servers.
Our environment involves simultaneous HEAD and branch development on our
Framework, as well as HEAD and branch development of applications based on
the Framework. We've got a multi-server development environment (dev only,
preview, and production) with CVS commits auto-published to the dev and
preview servers, according to CVS branch.
Our dev server has to support a stable CVS branch of the Framework in order
to facilitate stable application development. As a result, we're about to
begin maintaining multiple Apache processes, one per branch of the Framework
(HEAD, stable release branch, tagged release) in order to maintain a clean
environment and predictable application quality. Applications can be
simultaneously tested on the current Framework or a past tagged release, as
well as the stable branch and even the trunk.
My reasoning against solutions such as Apache::PerlVINC and StatINC is that
I want the environment in which an application is tested and developed to be
as close as possible to the final deployment environment. I even encourage
our developers to work with the proxy front-end so that they can see what
their cache-control and other headers are doing (of course, the back-end
Apache processes are always available to them on a different port). IMHO
these modules, while in many circumstances are quite useful, are not
applicable to our strict development environment. And while they may well
work okay in this environment, I don't want to take the chance because - I'm
a paranoid S.O.B. 8^)
Luckily, RAM is cheap these days...
===
To: "Brian Ferris" <bdferris@unity.ncsu.edu>
From: "Rob Bloodgood" <robb@empire2.com>
Subject: RE: Dynamic loading of development libraries
Date: Tue, 6 Mar 2001 10:52:28 -0800
> I'm currently a developer for an on-line publication using Apache /
> mod_perl / Mason. We currently have about six developers working on the
> project and I have been running into problems with concurrent work on the
> Perl libraries that power our site.
Just a few days ago, somebody suggested http://www.freevsd.org/ as a
solution for this kind of situation. I've reviewed it briefly, and it
appears to be able to do alot of what you seem to need.
===