swift/test/probe/test_object_expirer.py
Clay Gerrard c1dc2fa624 Add two vector timestamps
The normalized form of the X-Timestamp header looks like a float with a fixed
width to ensure stable string sorting - normalized timestamps look like
"1402464677.04188"

To support overwrites of existing data without modifying the original
timestamp but still maintain consistency a second internal offset
vector is append to the normalized timestamp form which compares and
sorts greater than the fixed width float format but less than a newer
timestamp.  The internalized format of timestamps looks like
"1402464677.04188_0000000000000000" - the portion after the underscore
is the offset and is a formatted hexadecimal integer.

The internalized form is not exposed to clients in responses from Swift.
Normal client operations will not create a timestamp with an offset.

The Timestamp class in common.utils supports internalized and normalized
formatting of timestamps and also comparison of timestamp values.  When the
offset value of a Timestamp is 0 - it's considered insignificant and need not
be represented in the string format; to support backwards compatibility during
a Swift upgrade the internalized and normalized form of a Timestamp with an
insignificant offset are identical.  When a timestamp includes an offset it
will always be represented in the internalized form, but is still excluded
from the normalized form.  Timestamps with an equivalent timestamp portion
(the float part) will compare and order by their offset.  Timestamps with a
greater timestamp portion will always compare and order greater than a
Timestamp with a lesser timestamp regardless of it's offset.  String
comparison and ordering is guaranteed for the internalized string format, and
is backwards compatible for normalized timestamps which do not include an
offset.

The reconciler currently uses a offset bump to ensure that objects can move to
the wrong storage policy and be moved back.  This use-case is valid because
the content represented by the user-facing timestamp is not modified in way.
Future consumers of the offset vector of timestamps should be mindful of HTTP
semantics of If-Modified and take care to avoid deviation in the response from
the object server without an accompanying change to the user facing timestamp.

DocImpact
Implements: blueprint storage-policies
Change-Id: Id85c960b126ec919a481dc62469bf172b7fb8549
2014-06-19 10:18:06 -07:00

133 lines
5.3 KiB
Python

#!/usr/bin/python -u
# 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.
import random
import unittest
import uuid
from nose import SkipTest
from swift.common.internal_client import InternalClient
from swift.common.manager import Manager
from swift.common.storage_policy import POLICIES
from swift.common.utils import Timestamp
from test.probe.common import reset_environment, get_to_final_state
from test.probe.test_container_merge_policy_index import BrainSplitter
from swiftclient import client
class TestObjectExpirer(unittest.TestCase):
def setUp(self):
if len(POLICIES) < 2:
raise SkipTest('Need more than one policy')
self.expirer = Manager(['object-expirer'])
self.expirer.start()
err = self.expirer.stop()
if err:
raise SkipTest('Unable to verify object-expirer service')
conf_files = []
for server in self.expirer.servers:
conf_files.extend(server.conf_files())
conf_file = conf_files[0]
self.client = InternalClient(conf_file, 'probe-test', 3)
(self.pids, self.port2server, self.account_ring, self.container_ring,
self.object_ring, self.policy, self.url, self.token,
self.account, self.configs) = reset_environment()
self.container_name = 'container-%s' % uuid.uuid4()
self.object_name = 'object-%s' % uuid.uuid4()
self.brain = BrainSplitter(self.url, self.token, self.container_name,
self.object_name)
def test_expirer_object_split_brain(self):
old_policy = random.choice(list(POLICIES))
wrong_policy = random.choice([p for p in POLICIES if p != old_policy])
# create an expiring object and a container with the wrong policy
self.brain.stop_primary_half()
self.brain.put_container(int(old_policy))
self.brain.put_object(headers={'X-Delete-After': 2})
# get the object timestamp
metadata = self.client.get_object_metadata(
self.account, self.container_name, self.object_name,
headers={'X-Backend-Storage-Policy-Index': int(old_policy)})
create_timestamp = Timestamp(metadata['x-timestamp'])
self.brain.start_primary_half()
# get the expiring object updates in their queue, while we have all
# the servers up
Manager(['object-updater']).once()
self.brain.stop_handoff_half()
self.brain.put_container(int(wrong_policy))
# don't start handoff servers, only wrong policy is available
# make sure auto-created containers get in the account listing
Manager(['container-updater']).once()
# this guy should no-op since it's unable to expire the object
self.expirer.once()
self.brain.start_handoff_half()
get_to_final_state()
# validate object is expired
found_in_policy = None
metadata = self.client.get_object_metadata(
self.account, self.container_name, self.object_name,
acceptable_statuses=(4,),
headers={'X-Backend-Storage-Policy-Index': int(old_policy)})
self.assert_('x-backend-timestamp' in metadata)
self.assertEqual(Timestamp(metadata['x-backend-timestamp']),
create_timestamp)
# but it is still in the listing
for obj in self.client.iter_objects(self.account,
self.container_name):
if self.object_name == obj['name']:
break
else:
self.fail('Did not find listing for %s' % self.object_name)
# clear proxy cache
client.post_container(self.url, self.token, self.container_name, {})
# run the expirier again after replication
self.expirer.once()
# object is not in the listing
for obj in self.client.iter_objects(self.account,
self.container_name):
if self.object_name == obj['name']:
self.fail('Found listing for %s' % self.object_name)
# and validate object is tombstoned
found_in_policy = None
for policy in POLICIES:
metadata = self.client.get_object_metadata(
self.account, self.container_name, self.object_name,
acceptable_statuses=(4,),
headers={'X-Backend-Storage-Policy-Index': int(policy)})
if 'x-backend-timestamp' in metadata:
if found_in_policy:
self.fail('found object in %s and also %s' %
(found_in_policy, policy))
found_in_policy = policy
self.assert_('x-backend-timestamp' in metadata)
self.assert_(Timestamp(metadata['x-backend-timestamp']) >
create_timestamp)
if __name__ == "__main__":
unittest.main()