RE: Dynamic loading of development libraries
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. Good luck! L8r, Rob
Dynamic loading of development libraries
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? Thanks, Brian Ferris
Re: Dynamic loading of development libraries
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 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? Thanks, Brian Ferris _ Stas Bekman JAm_pH -- Just Another mod_perl Hacker http://stason.org/ mod_perl Guide http://perl.apache.org/guide mailto:[EMAIL PROTECTED] http://apachetoday.com http://logilune.com/ http://singlesheaven.com http://perl.apache.org http://perlmonth.com/
Re: Dynamic loading of development libraries
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.
--
Steven Lembark 2930 W. Palmer St.
Chicago, IL 60647
[EMAIL PROTECTED] 800-762-1582
RE: Dynamic loading of development libraries
Or set MaxClients to 1 if you do not have too many developers and/or your development server doesn't suck ; ) 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.
RE: Dynamic loading of development libraries
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... Steve -Original Message- From: Brian Ferris [mailto:[EMAIL PROTECTED]] Sent: Saturday, March 03, 2001 12:30 PM To: [EMAIL PROTECTED] Subject: Dynamic loading of development libraries 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? Thanks, Brian Ferris
