swift/test/unit/common/test_memcached.py
Peter Portante 1ac7b88a27 Use a delta timeout for memcache where possible
We use a delta timeout value for timeouts under 30 days (in seconds)
since that is the limit which the memcached protocols will recognize a
timeout as a delta. Greater than 30 days and it interprets it as an
absolute time in seconds since the epoch.

This helps to address an often difficult-to-debug problem of time
drift between memcache clients and the memcache servers. Prior to this
change, if a client's time drifts behind the servers, short timeouts
run the danger of not being cached at all. If a client's time drifts
ahead of the servers, short timeouts run the danger of persisting too
long. Using delta's avoids this affect. For absolute timeouts 30 days
or more in the future small time drifts between clients and servers
are inconsequential.

See also bug 1076148 (https://bugs.launchpad.net/swift/+bug/1076148).

This also fixes incr and decr to handle timeout values in the same way
timeouts are handled for set operations.

Change-Id: Ie36dbcedfe9b4db9f77ed4ea9b70ff86c5773310
Signed-off-by: Peter Portante <peter.portante@redhat.com>
2012-11-16 14:57:36 -05:00

314 lines
14 KiB
Python

# -*- coding: utf8 -*-
# Copyright (c) 2010-2012 OpenStack, LLC.
#
# 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.
""" Tests for swift.common.utils """
from __future__ import with_statement
import logging
import socket
import time
import unittest
from uuid import uuid4
from swift.common import memcached
from test.unit import NullLoggingHandler
class ExplodingMockMemcached(object):
exploded = False
def sendall(self, string):
self.exploded = True
raise socket.error()
def readline(self):
self.exploded = True
raise socket.error()
def read(self, size):
self.exploded = True
raise socket.error()
class MockMemcached(object):
def __init__(self):
self.inbuf = ''
self.outbuf = ''
self.cache = {}
self.down = False
self.exc_on_delete = False
self.read_return_none = False
def sendall(self, string):
if self.down:
raise Exception('mock is down')
self.inbuf += string
while '\n' in self.inbuf:
cmd, self.inbuf = self.inbuf.split('\n', 1)
parts = cmd.split()
if parts[0].lower() == 'set':
self.cache[parts[1]] = parts[2], parts[3], \
self.inbuf[:int(parts[4])]
self.inbuf = self.inbuf[int(parts[4]) + 2:]
if len(parts) < 6 or parts[5] != 'noreply':
self.outbuf += 'STORED\r\n'
elif parts[0].lower() == 'add':
value = self.inbuf[:int(parts[4])]
self.inbuf = self.inbuf[int(parts[4]) + 2:]
if parts[1] in self.cache:
if len(parts) < 6 or parts[5] != 'noreply':
self.outbuf += 'NOT_STORED\r\n'
else:
self.cache[parts[1]] = parts[2], parts[3], value
if len(parts) < 6 or parts[5] != 'noreply':
self.outbuf += 'STORED\r\n'
elif parts[0].lower() == 'delete':
if self.exc_on_delete:
raise Exception('mock is has exc_on_delete set')
if parts[1] in self.cache:
del self.cache[parts[1]]
if 'noreply' not in parts:
self.outbuf += 'DELETED\r\n'
elif 'noreply' not in parts:
self.outbuf += 'NOT_FOUND\r\n'
elif parts[0].lower() == 'get':
for key in parts[1:]:
if key in self.cache:
val = self.cache[key]
self.outbuf += 'VALUE %s %s %s\r\n' % (
key, val[0], len(val[2]))
self.outbuf += val[2] + '\r\n'
self.outbuf += 'END\r\n'
elif parts[0].lower() == 'incr':
if parts[1] in self.cache:
val = list(self.cache[parts[1]])
val[2] = str(int(val[2]) + int(parts[2]))
self.cache[parts[1]] = val
self.outbuf += str(val[2]) + '\r\n'
else:
self.outbuf += 'NOT_FOUND\r\n'
elif parts[0].lower() == 'decr':
if parts[1] in self.cache:
val = list(self.cache[parts[1]])
if int(val[2]) - int(parts[2]) > 0:
val[2] = str(int(val[2]) - int(parts[2]))
else:
val[2] = '0'
self.cache[parts[1]] = val
self.outbuf += str(val[2]) + '\r\n'
else:
self.outbuf += 'NOT_FOUND\r\n'
def readline(self):
if self.read_return_none:
return None
if self.down:
raise Exception('mock is down')
if '\n' in self.outbuf:
response, self.outbuf = self.outbuf.split('\n', 1)
return response + '\n'
def read(self, size):
if self.down:
raise Exception('mock is down')
if len(self.outbuf) >= size:
response = self.outbuf[:size]
self.outbuf = self.outbuf[size:]
return response
class TestMemcached(unittest.TestCase):
""" Tests for swift.common.memcached"""
def test_get_conns(self):
sock1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock1.bind(('127.0.0.1', 0))
sock1.listen(1)
sock1ipport = '%s:%s' % sock1.getsockname()
sock2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock2.bind(('127.0.0.1', 0))
sock2.listen(1)
orig_port = memcached.DEFAULT_MEMCACHED_PORT
try:
sock2ip, memcached.DEFAULT_MEMCACHED_PORT = sock2.getsockname()
sock2ipport = '%s:%s' % (sock2ip, memcached.DEFAULT_MEMCACHED_PORT)
# We're deliberately using sock2ip (no port) here to test that the
# default port is used.
memcache_client = memcached.MemcacheRing([sock1ipport, sock2ip])
one = two = True
while one or two: # Run until we match hosts one and two
key = uuid4().hex
for conn in memcache_client._get_conns(key):
peeripport = '%s:%s' % conn[2].getpeername()
self.assert_(peeripport in (sock1ipport, sock2ipport))
if peeripport == sock1ipport:
one = False
if peeripport == sock2ipport:
two = False
finally:
memcached.DEFAULT_MEMCACHED_PORT = orig_port
def test_set_get(self):
memcache_client = memcached.MemcacheRing(['1.2.3.4:11211'])
mock = MockMemcached()
memcache_client._client_cache['1.2.3.4:11211'] = [(mock, mock)] * 2
memcache_client.set('some_key', [1, 2, 3])
self.assertEquals(memcache_client.get('some_key'), [1, 2, 3])
self.assertEquals(mock.cache.values()[0][1], '0')
memcache_client.set('some_key', [4, 5, 6])
self.assertEquals(memcache_client.get('some_key'), [4, 5, 6])
memcache_client.set('some_key', ['simple str', 'utf8 str éà'])
# As per http://wiki.openstack.org/encoding,
# we should expect to have unicode
self.assertEquals(
memcache_client.get('some_key'), ['simple str', u'utf8 str éà'])
self.assert_(float(mock.cache.values()[0][1]) == 0)
memcache_client.set('some_key', [1, 2, 3], timeout=10)
self.assertEquals(mock.cache.values()[0][1], '10')
sixtydays = 60 * 24 * 60 * 60
esttimeout = time.time() + sixtydays
memcache_client.set('some_key', [1, 2, 3], timeout=sixtydays)
self.assert_(-1 <= float(mock.cache.values()[0][1]) - esttimeout <= 1)
def test_incr(self):
memcache_client = memcached.MemcacheRing(['1.2.3.4:11211'])
mock = MockMemcached()
memcache_client._client_cache['1.2.3.4:11211'] = [(mock, mock)] * 2
memcache_client.incr('some_key', delta=5)
self.assertEquals(memcache_client.get('some_key'), '5')
memcache_client.incr('some_key', delta=5)
self.assertEquals(memcache_client.get('some_key'), '10')
memcache_client.incr('some_key', delta=1)
self.assertEquals(memcache_client.get('some_key'), '11')
memcache_client.incr('some_key', delta=-5)
self.assertEquals(memcache_client.get('some_key'), '6')
memcache_client.incr('some_key', delta=-15)
self.assertEquals(memcache_client.get('some_key'), '0')
mock.read_return_none = True
self.assertRaises(memcached.MemcacheConnectionError,
memcache_client.incr, 'some_key', delta=-15)
def test_incr_w_timeout(self):
memcache_client = memcached.MemcacheRing(['1.2.3.4:11211'])
mock = MockMemcached()
memcache_client._client_cache['1.2.3.4:11211'] = [(mock, mock)] * 2
memcache_client.incr('some_key', delta=5, timeout=55)
self.assertEquals(memcache_client.get('some_key'), '5')
self.assertEquals(mock.cache.values()[0][1], '55')
memcache_client.delete('some_key')
self.assertEquals(memcache_client.get('some_key'), None)
fiftydays = 50 * 24 * 60 * 60
esttimeout = time.time() + fiftydays
memcache_client.incr('some_key', delta=5, timeout=fiftydays)
self.assertEquals(memcache_client.get('some_key'), '5')
self.assert_(-1 <= float(mock.cache.values()[0][1]) - esttimeout <= 1)
memcache_client.delete('some_key')
self.assertEquals(memcache_client.get('some_key'), None)
memcache_client.incr('some_key', delta=5)
self.assertEquals(memcache_client.get('some_key'), '5')
self.assertEquals(mock.cache.values()[0][1], '0')
memcache_client.incr('some_key', delta=5, timeout=55)
self.assertEquals(memcache_client.get('some_key'), '10')
self.assertEquals(mock.cache.values()[0][1], '0')
def test_decr(self):
memcache_client = memcached.MemcacheRing(['1.2.3.4:11211'])
mock = MockMemcached()
memcache_client._client_cache['1.2.3.4:11211'] = [(mock, mock)] * 2
memcache_client.decr('some_key', delta=5)
self.assertEquals(memcache_client.get('some_key'), '0')
memcache_client.incr('some_key', delta=15)
self.assertEquals(memcache_client.get('some_key'), '15')
memcache_client.decr('some_key', delta=4)
self.assertEquals(memcache_client.get('some_key'), '11')
memcache_client.decr('some_key', delta=15)
self.assertEquals(memcache_client.get('some_key'), '0')
mock.read_return_none = True
self.assertRaises(memcached.MemcacheConnectionError,
memcache_client.decr, 'some_key', delta=15)
def test_retry(self):
logging.getLogger().addHandler(NullLoggingHandler())
memcache_client = memcached.MemcacheRing(
['1.2.3.4:11211', '1.2.3.5:11211'])
mock1 = ExplodingMockMemcached()
mock2 = MockMemcached()
memcache_client._client_cache['1.2.3.4:11211'] = [(mock2, mock2)]
memcache_client._client_cache['1.2.3.5:11211'] = [(mock1, mock1)]
memcache_client.set('some_key', [1, 2, 3])
self.assertEquals(memcache_client.get('some_key'), [1, 2, 3])
self.assertEquals(mock1.exploded, True)
def test_delete(self):
memcache_client = memcached.MemcacheRing(['1.2.3.4:11211'])
mock = MockMemcached()
memcache_client._client_cache['1.2.3.4:11211'] = [(mock, mock)] * 2
memcache_client.set('some_key', [1, 2, 3])
self.assertEquals(memcache_client.get('some_key'), [1, 2, 3])
memcache_client.delete('some_key')
self.assertEquals(memcache_client.get('some_key'), None)
def test_multi(self):
memcache_client = memcached.MemcacheRing(['1.2.3.4:11211'])
mock = MockMemcached()
memcache_client._client_cache['1.2.3.4:11211'] = [(mock, mock)] * 2
memcache_client.set_multi(
{'some_key1': [1, 2, 3], 'some_key2': [4, 5, 6]}, 'multi_key')
self.assertEquals(
memcache_client.get_multi(('some_key2', 'some_key1'), 'multi_key'),
[[4, 5, 6], [1, 2, 3]])
self.assertEquals(mock.cache.values()[0][1], '0')
self.assertEquals(mock.cache.values()[1][1], '0')
memcache_client.set_multi(
{'some_key1': [1, 2, 3], 'some_key2': [4, 5, 6]}, 'multi_key',
timeout=10)
self.assertEquals(mock.cache.values()[0][1], '10')
self.assertEquals(mock.cache.values()[1][1], '10')
fortydays = 50 * 24 * 60 * 60
esttimeout = time.time() + fortydays
memcache_client.set_multi(
{'some_key1': [1, 2, 3], 'some_key2': [4, 5, 6]}, 'multi_key',
timeout=fortydays)
self.assert_(-1 <= float(mock.cache.values()[0][1]) - esttimeout <= 1)
self.assert_(-1 <= float(mock.cache.values()[1][1]) - esttimeout <= 1)
self.assertEquals(memcache_client.get_multi(
('some_key2', 'some_key1', 'not_exists'), 'multi_key'),
[[4, 5, 6], [1, 2, 3], None])
def test_serialization(self):
memcache_client = memcached.MemcacheRing(['1.2.3.4:11211'],
allow_pickle=True)
mock = MockMemcached()
memcache_client._client_cache['1.2.3.4:11211'] = [(mock, mock)] * 2
memcache_client.set('some_key', [1, 2, 3])
self.assertEquals(memcache_client.get('some_key'), [1, 2, 3])
memcache_client._allow_pickle = False
memcache_client._allow_unpickle = True
self.assertEquals(memcache_client.get('some_key'), [1, 2, 3])
memcache_client._allow_unpickle = False
self.assertEquals(memcache_client.get('some_key'), None)
memcache_client.set('some_key', [1, 2, 3])
self.assertEquals(memcache_client.get('some_key'), [1, 2, 3])
memcache_client._allow_unpickle = True
self.assertEquals(memcache_client.get('some_key'), [1, 2, 3])
memcache_client._allow_pickle = True
self.assertEquals(memcache_client.get('some_key'), [1, 2, 3])
if __name__ == '__main__':
unittest.main()