Django 1.6 w/ gunicorn - OperationalError: (2006, 'MySQL server has gone away') - mysql

Question

In the process of upgrading to Django 1.6 I've started to get a frequent OperationalError: (2006, 'MySQL server has gone away') message on requests to the gunicorn server I use to run the django app. These errors occur instantly from the moment the server is started, on requests that should only take a second which makes me doubt that it is a timeout issue. This error isn't present on the old 1.4 branch of the project and the 1.6 branch doesn't behave this way if it's served simply through django-admin.py runserver.
I generally run gunicorn through an sv process (though it errors if I run it manually too) with the command django-admin.py run_gunicorn --workers=4 -b localhost:8000 which results in many requests, even ones for static media, returning with:
[ERROR] 2015-07-29 14:30:27,931 - gunicorn.error:260 - Error handling request
Traceback (most recent call last):
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/gunicorn/workers/sync.py", line 125, in handle_request
respiter = self.wsgi(environ, resp.start_response)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/core/handlers/wsgi.py", line 187, in __call__
self.load_middleware()
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 47, in load_middleware
mw_instance = mw_class()
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/middleware/locale.py", line 24, in __init__
for url_pattern in get_resolver(None).url_patterns:
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 365, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 360, in urlconf_module
self._urlconf_module = import_module(self.urlconf_name)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/utils/importlib.py", line 40, in import_module
__import__(name)
File "/opt/apps/maplecroft/versions/current/websites/maplecroft/urls.py", line 2, in <module>
from maplecroft.views import RiskAtlasesLandingView
File "/opt/apps/maplecroft/versions/current/maplecroft/views.py", line 40, in <module>
import maplecroft.search as _search
File "/opt/apps/maplecroft/versions/current/maplecroft/search.py", line 71, in <module>
class MaplecroftSearchForm(SearchForm):
File "/opt/apps/maplecroft/versions/current/maplecroft/search.py", line 111, in MaplecroftSearchForm
choices=model_choices(),
File "/opt/apps/maplecroft/versions/current/maplecroft/search.py", line 57, in model_choices
for category in reversed(Category.objects.filter(parent=None)):
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/models/query.py", line 77, in __len__
self._fetch_all()
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/models/query.py", line 857, in _fetch_all
self._result_cache = list(self.iterator())
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/models/query.py", line 220, in iterator
for row in compiler.results_iter():
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 713, in results_iter
for rows in self.execute_sql(MULTI):
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 786, in execute_sql
cursor.execute(sql, params)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/backends/util.py", line 69, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/backends/util.py", line 53, in execute
return self.cursor.execute(sql, params)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/utils.py", line 99, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/backends/util.py", line 53, in execute
return self.cursor.execute(sql, params)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/django/db/backends/mysql/base.py", line 124, in execute
return self.cursor.execute(query, args)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/MySQLdb/cursors.py", line 174, in execute
self.errorhandler(self, exc, value)
File "/opt/envs/maplecroft/local/lib/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
raise errorclass, errorvalue
OperationalError: (2006, 'MySQL server has gone away')
However, if I drop to --workers=1 everything seems to run smoothly so my current thoughts are that it is an issue with the threaded workers feature of gunicorn?
Edit: I just tried upgrading gunicorn to the latest version (was on 0.17.2) but that doesn't seem to have made a difference.
I am wondering if this question: https://serverfault.com/questions/407612/error-2006-mysql-server-has-gone-away is relevant, but struggling to overlay it with my current issues

Answer 1

It appears that it was the gunicorn version after all- I tried upgrading gunicorn but was still using the django-admin.py run_gunicorn method of starting the server. Upgrading gunicorn and switching to the non-deprecated gunicorn wsgi:application method solved it.