ironic/ironic/tests/test_hash_ring.py

120 lines
4.8 KiB
Python

# Copyright 2013 Hewlett-Packard Development Company, L.P.
# 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.
from oslo.config import cfg
from ironic.common import exception
from ironic.common import hash_ring as hash
from ironic.tests import base
CONF = cfg.CONF
class HashRingTestCase(base.TestCase):
# NOTE(deva): the mapping used in these tests is as follows:
# if hosts = [foo, bar]:
# fake -> foo, bar
# if hosts = [foo, bar, baz]:
# fake -> foo, bar, baz
# fake-again -> bar, baz, foo
def test_create_ring(self):
hosts = ['foo', 'bar']
replicas = 2
ring = hash.HashRing(hosts, replicas=replicas)
self.assertEqual(hosts, ring.hosts)
self.assertEqual(replicas, ring.replicas)
def test_create_with_different_partition_counts(self):
hosts = ['foo', 'bar']
CONF.set_override('hash_partition_exponent', 2)
ring = hash.HashRing(hosts)
self.assertEqual(2 ** 2, len(ring.part2host))
CONF.set_override('hash_partition_exponent', 8)
ring = hash.HashRing(hosts)
self.assertEqual(2 ** 8, len(ring.part2host))
CONF.set_override('hash_partition_exponent', 16)
ring = hash.HashRing(hosts)
self.assertEqual(2 ** 16, len(ring.part2host))
def test_distribution_one_replica(self):
hosts = ['foo', 'bar', 'baz']
ring = hash.HashRing(hosts, replicas=1)
self.assertEqual(['foo'], ring.get_hosts('fake'))
self.assertEqual(['bar'], ring.get_hosts('fake-again'))
def test_distribution_two_replicas(self):
hosts = ['foo', 'bar', 'baz']
ring = hash.HashRing(hosts, replicas=2)
self.assertEqual(['foo', 'bar'], ring.get_hosts('fake'))
self.assertEqual(['bar', 'baz'], ring.get_hosts('fake-again'))
def test_distribution_three_replicas(self):
hosts = ['foo', 'bar', 'baz']
ring = hash.HashRing(hosts, replicas=3)
self.assertEqual(['foo', 'bar', 'baz'], ring.get_hosts('fake'))
self.assertEqual(['bar', 'baz', 'foo'], ring.get_hosts('fake-again'))
def test_ignore_hosts(self):
hosts = ['foo', 'bar', 'baz']
ring = hash.HashRing(hosts, replicas=1)
self.assertEqual(['bar'], ring.get_hosts('fake',
ignore_hosts=['foo']))
self.assertEqual(['baz'], ring.get_hosts('fake',
ignore_hosts=['foo', 'bar']))
self.assertEqual([], ring.get_hosts('fake',
ignore_hosts=hosts))
def test_ignore_hosts_with_replicas(self):
hosts = ['foo', 'bar', 'baz']
ring = hash.HashRing(hosts, replicas=2)
self.assertEqual(['bar', 'baz'], ring.get_hosts('fake',
ignore_hosts=['foo']))
self.assertEqual(['baz'], ring.get_hosts('fake',
ignore_hosts=['foo', 'bar']))
self.assertEqual(['baz', 'foo'], ring.get_hosts('fake-again',
ignore_hosts=['bar']))
self.assertEqual(['foo'], ring.get_hosts('fake-again',
ignore_hosts=['bar', 'baz']))
self.assertEqual([], ring.get_hosts('fake',
ignore_hosts=hosts))
def test_more_replicas_than_hosts(self):
hosts = ['foo', 'bar']
ring = hash.HashRing(hosts, replicas=10)
self.assertEqual(hosts, ring.get_hosts('fake'))
def test_ignore_non_existent_host(self):
hosts = ['foo', 'bar']
ring = hash.HashRing(hosts, replicas=1)
self.assertEqual(['foo'], ring.get_hosts('fake',
ignore_hosts=['baz']))
def test_create_ring_invalid_data(self):
hosts = None
self.assertRaises(exception.Invalid,
hash.HashRing,
hosts)
def test_get_hosts_invalid_data(self):
hosts = ['foo', 'bar']
ring = hash.HashRing(hosts)
self.assertRaises(exception.Invalid,
ring.get_hosts,
None)