improve speed of metadata

 * don't load every possible answer, only do what is needed
 * cache instance data for a given address for a 15 seconds
   using either memcache or fake memcache (in-memory).
   This means only a single queue/db lookup for multiple calls
   to metadata service
 * add cache expirey to fake memcache (don't grow forever)
   and move it to nova.common.memorycache

Addresses Bug #851159

Change-Id: Icf794156e055b18915b8b5be9ba2ab97d2338bbe

2 files changed, 0 insertions, 60 deletions

diff --git a/nova/testing/fake/__init__.py b/nova/testing/fake/__init__.py
index d9eebbd23..5cdad4717 100644
--- a/nova/testing/fake/__init__.py
+++ b/nova/testing/fake/__init__.py
@@ -1,2 +1 @@
-import memcache
 import rabbit
diff --git a/nova/testing/fake/memcache.py b/nova/testing/fake/memcache.py
deleted file mode 100644
index e4f238aa9..000000000
--- a/nova/testing/fake/memcache.py
+++ /dev/null
@@ -1,59 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-
-# Copyright 2010 United States Government as represented by the
-# Administrator of the National Aeronautics and Space Administration.
-# All Rights Reserved.
-#
-#    Licensed under the Apache License, Version 2.0 (the "License"); you may
-#    not use this file except in compliance with the License. You may obtain
-#    a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-#    Unless required by applicable law or agreed to in writing, software
-#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-#    License for the specific language governing permissions and limitations
-#    under the License.
-
-"""Super simple fake memcache client."""
-
-from nova import utils
-
-
-class Client(object):
-    """Replicates a tiny subset of memcached client interface."""
-
-    def __init__(self, *args, **kwargs):
-        """Ignores the passed in args."""
-        self.cache = {}
-
-    def get(self, key):
-        """Retrieves the value for a key or None."""
-        (timeout, value) = self.cache.get(key, (0, None))
-        if timeout == 0 or utils.utcnow_ts() < timeout:
-            return value
-        return None
-
-    def set(self, key, value, time=0, min_compress_len=0):
-        """Sets the value for a key."""
-        timeout = 0
-        if time != 0:
-            timeout = utils.utcnow_ts() + time
-        self.cache[key] = (timeout, value)
-        return True
-
-    def add(self, key, value, time=0, min_compress_len=0):
-        """Sets the value for a key if it doesn't exist."""
-        if not self.get(key) is None:
-            return False
-        return self.set(key, value, time, min_compress_len)
-
-    def incr(self, key, delta=1):
-        """Increments the value for a key."""
-        value = self.get(key)
-        if value is None:
-            return None
-        new_value = int(value) + delta
-        self.cache[key] = (self.cache[key][0], str(new_value))
-        return new_value