问Django 1.6w/ gunicorn - OperationalError：(2006年，'MySQL服务器已经消失‘)

EN

[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')