External-Mirrors/awx
2
0
Fork 0
mirror of https://github.com/ansible/awx.git synced 2026-01-11 01:57:35 -03:30
Code Issues Packages Projects Releases Wiki Activity

forcibly close DB and cache socket connection post-fork

Browse Source 
we've seen evidence of a race condition on fork for awx.conf.Setting
access; in the past, we've attempted to solve this by explicitly closing
connections pre-fork, but we've seen evidence that this isn't always
good enough

this patch is an attempt to close connections post-fork so that sockets
aren't inherited post fork, leading to bizarre race conditions in
setting access
This commit is contained in:
Ryan Petrello 2020-11-12 13:35:05 -05:00
parent 76fd63ba5f
commit adfd8ed26b
No known key found for this signature in database
GPG Key ID: F2AA5F2122351777
1 changed files with 23 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
awx/conf/settings.py
View File

@ -4,6 +4,7 @@ import logging
import sys
import threading
import time
import os
# Django
from django.conf import LazySettings
@ -247,6 +248,7 @@ class SettingsWrapper(UserSettingsHolder):
# These values have to be stored via self.__dict__ in this way to get
# around the magic __setattr__ method on this class (which is used to
# store API-assigned settings in the database).
self.__dict__['__forks__'] = {}
self.__dict__['default_settings'] = default_settings
self.__dict__['_awx_conf_settings'] = self
self.__dict__['_awx_conf_preload_expires'] = None
@ -255,6 +257,26 @@ class SettingsWrapper(UserSettingsHolder):
self.__dict__['cache'] = EncryptedCacheProxy(cache, registry)
self.__dict__['registry'] = registry
# record the current pid so we compare it post-fork for
# processes like the dispatcher and callback receiver
self.__dict__['pid'] = os.getpid()
def __clean_on_fork__(self):
pid = os.getpid()
# if the current pid does *not* match the value on self, it means
# that value was copied on fork, and we're now in a *forked* process;
# the *first* time we enter this code path (on setting access),
# forcibly close DB/cache sockets and set a marker so we don't run
# this code again _in this process_
#
if pid != self.__dict__['pid'] and pid not in self.__dict__['__forks__']:
self.__dict__['__forks__'][pid] = True
# It's important to close these post-fork, because we
# don't want the forked processes to inherit the open sockets
# for the DB and cache connections (that way lies race conditions)
connection.close()
django_cache.close()
@cached_property
def all_supported_settings(self):
return self.registry.get_registered_settings()
@ -330,6 +352,7 @@ class SettingsWrapper(UserSettingsHolder):
self.cache.set_many(settings_to_cache, timeout=SETTING_CACHE_TIMEOUT)
def _get_local(self, name, validate=True):
self.__clean_on_fork__()
self._preload_cache()
cache_key = Setting.get_cache_key(name)
try: