id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
24574	python manage.py runserver sleeps forever because of threading lock	Krish	nobody	"I have upgraded Django 1.6 o 1.7.7. I was run my project using 'python manage.py runserver' command. It went well in test server. However, when I tried same in production server, it sleeps forever. Detail Server info is attached below. Doing trackback, I figure out problem, It lies on django.apps.registry.populate function. Trace back steps as follows:

1. Command line execution starts. 
{{{#!python
django.core.management:: utility.execute()
}}}

2. It calls application setup process, where it loads enabled Apps
{{{#!python
django.core.management ::jango.setup()
django.setup:: apps.populate(settings.INSTALLED_APPS)
}}}

3. Thread starts threading lock process, so that same application not loaded twice.
{{{#!python
django.apps.registry::with self._lock:
}}}

4. It goes through for each app,
{{{#!python
django.apps.registry::app_config.ready()
...
# after many lines of codes
...
for app_config in self.get_app_configs():
app_config.ready()
}}}
5. When it matches <AdminConfig: admin>, it calls to
{{{#!python
django.contrib.admin.apps:: self.module.autodiscover()
django.contrib.admin:: autodiscover_modules('admin', register_to=site)
}}}
56. autodiscover_modules agains calls django.setup(). I don't have full traceback. But it goes like:
{{{#!python
django.core.management ::django.setup()
}}}
{{{#!python
django.setup::apps.populate(settings.INSTALLED_APPS)
}}}
{{{#!python
django.apps.registry::with self._lock:
}}}

Application stuck here in django.apps.registry::with self._lock: line because the threading lock has been already acquired and not released.

'''Python:'''
Python 2.7.6 on both server

'''Dev Server:'''
Distributor ID:	Ubuntu
Description:	Ubuntu 14.04.1 LTS
Release:	14.04
Codename:	trusty
CPU: 2.40GHz x 1
MemTotal:   1017880kb

'''Production Server:'''
Distributor ID:	Ubuntu
Description:	Ubuntu 14.04 LTS
Release:	14.04
Codename:	trusty
CPU: 2.00GHz x 24
MemTotal:       4942810"	Bug	new	Migrations	1.7	Normal		threading lock, manage.py		Unreviewed	0	0	0	0	0	0