On Jan 3, 5:14 am, Matt Haggard <[EMAIL PROTECTED]> wrote:
> I'm (in the process of) using pylons in a production environment and
> still have a few questions:
>
> 1) Do I really have to restart the server every time I make a change
> (controller/model)? I can foresee making many changes and some which
> require immediate attention, but restarting the server in the middle
> of the day would not be an option. So, do I have to make changes at
> night? Is there no way for the server to adopt the changes without
> killing all connections?
>
> 2) The system will be composed of multiple apps... (perhaps as many as
> 20 or more) so would it be better (if I need to restart after every
> change) to have all the apps served by their own servers? I mean, is
> it better to have 20 instances of the paster server if uptime is such
> a priority?
>
> 3) In serving several apps (thanks to Ian Bicking for the help to get
> that going!) like this:
> [composite:main]
> use = egg:Paste#urlmap
> / = config:home_app/development.ini
> /app2 = config:app2/development.ini
> ...
>
> how do I make app2 aware that all of his urls are based off of /app2?
> well... actually, it is already aware of that. I'm really asking: Is
> there a way for app2 to know that the home directory is just
> plain / ? This comes up because I use a shared repository for images
> and when I reference images from app2 with src="images/something.jpg"
> it looks for the image at the
> urlhttp://127.0.0.1:5000/app2/images/something.jpg
> instead ofhttp://127.0.0.1:5000/images/something.jpg. Also, I'd like
> for app2 to be able to link back to / without explicitly hard-coding
> that url (I can see in the future bumping everything up a directory...
> making / into /section and /app2 into /section/app2)
>
> Am I just going about this the wrong way?
Many Pylons folks have an aversion to mod_wsgi and will refuse to use
it on religious grounds without even trying it, but the problems you
are trying to solve are exactly the sort of the things that mod_wsgi
is really good for. This is because mod_wsgi handles both the restart
case as well as the problem of splitting up a monolithic application
to run across multiple distinct processes. The steps required to do
this are relative easy and don't require having to setup lots of
distinct server instances each with a supervisor system as Apache/
mod_wsgi will handle that all for you automatically.
Starting with separation of applications into distinct processes to
allow them to be individually restart, one would take your composite
application and create separate .ini files for each application. One
would just then mount them as separate WSGI applications. For example:
WSGIScriptAlias /app2 /some/path/app2.wsgi
WSGIScriptAlias / /some/path/home_app.wsgi
Leave it like that and all you have done is separated the applications
so that they run within distinct sub interpreters in the same
processes. Add daemon processes to the mix though and you can delegate
each to run in a separate process and/or processes.
WSGIDaemonProcess app2 threads=25
WSGIScriptAlias /app2 /some/path/app2.wsgi
<Location /app2>
WSGIProcessGroup app2
WSGIReloadMechanism Process
</Location>
WSGIDaemonProcess home_app threads=25
WSGIScriptAlias / /some/path/home_app.wsgi
<Location />
WSGIProcessGroup home_app
WSGIReloadMechanism Process
</Location>
Each application now runs in a separate process with 25 threads.
Having enabled process reload mechanism available with mod_wsgi 2.0,
to restart an application all you need to do is touch (ie., change
modification time) of the WSGI script file for that application and it
wll be automatically restarted prior to next request it receives. The
restart of that application doesn't affect other applications not
require Apache as a whole to be restarted.
The contents of those WSGI script files is pretty trivial and just
setup the WSGI application entry point.
import os, sys
sys.path.append('/usr/local/pylons/home_app')
from paste.deploy import loadapp
application = loadapp('config:/usr/local/pylons/home_app/
development.ini')
Although relatively easy to setup, it should do pretty well what you
want.
Graham
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"pylons-discuss" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/pylons-discuss?hl=en
-~----------~----~----~----~------~----~------~--~---
