Fixed #5133 -- Explicitly close memcached connections after each request

(similar to database connection management). We can't effectively manage the
lifecycle by pooling connections and recent versions of python-memcache can
lead to connection exhaustion in some quite reasonable setups.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8418 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/cache/__init__.py

@@ -17,6 +17,7 @@ See docs/cache.txt for information on the public API.
 
 from cgi import parse_qsl
 from django.conf import settings
+from django.core import signals
 from django.core.cache.backends.base import InvalidCacheBackendError
 
 # Name for use in settings file --> name of module in "backends" directory.
@@ -54,3 +55,10 @@ def get_cache(backend_uri):
     return getattr(module, 'CacheClass')(host, params)
 
 cache = get_cache(settings.CACHE_BACKEND)
+
+# Some caches -- pythont-memcached in particular -- need to do a cleanup at the
+# end of a request cycle. If the cache provides a close() method, wire it up
+# here.
+if hasattr(cache, 'close'):
+    signals.request_finished.connect(cache.close)
+

django/core/cache/backends/memcached.py

@@ -39,3 +39,7 @@ class CacheClass(BaseCache):
 
     def get_many(self, keys):
         return self._cache.get_multi(map(smart_str,keys))
+
+    def close(self, **kwargs):
+        self._cache.disconnect_all()
+