def test_distribution_three_replicas(self):
hosts = ['foo', 'bar', 'baz']
ring = hash_ring.HashRing(hosts, replicas=3)
fake_1_hosts = ring.get_hosts('fake')
fake_2_hosts = ring.get_hosts('fake-again')
# We should have two hosts for each thing
self.assertThat(fake_1_hosts, matchers.HasLength(3))
self.assertThat(fake_2_hosts, matchers.HasLength(3))
# And they must not be the same answers even on this simple data
# because if they were we'd be making the active replica a hot spot.
self.assertNotEqual(fake_1_hosts, fake_2_hosts)
self.assertNotEqual(fake_1_hosts[0], fake_2_hosts[0])
def test__hash2int_returns_int(self, mock_md5):
CONF.set_override('hash_partition_exponent', 0)
r1 = 32 * 'a'
r2 = 32 * 'b'
mock_md5.return_value.hexdigest.side_effect = [r1, r2]
hosts = ['foo', 'bar']
replicas = 1
ring = hash_ring.HashRing(hosts, replicas=replicas)
self.assertIn(int(r1, 16), ring._host_hashes)
self.assertIn(int(r2, 16), ring._host_hashes)
def test_ignore_hosts(self):
hosts = ['foo', 'bar', 'baz']
ring = hash_ring.HashRing(hosts, replicas=1)
equals_bar_or_baz = matchers.MatchesAny(
matchers.Equals(['bar']),
matchers.Equals(['baz']))
self.assertThat(
ring.get_hosts('fake', ignore_hosts=['foo']),
equals_bar_or_baz)
self.assertThat(
ring.get_hosts('fake', ignore_hosts=['foo', 'bar']),
equals_bar_or_baz)
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 __init__(self, topic=None):
if topic is None:
topic = manager.MANAGER_TOPIC
# Initialize consistent hash ring
self.hash_rings = {}
d2c = dbapi.get_instance().get_active_driver_dict()
for driver in d2c.keys():
self.hash_rings[driver] = hash.HashRing(d2c[driver])
super(ConductorAPI, self).__init__(
topic=topic,
serializer=objects_base.IronicObjectSerializer(),
default_version=self.RPC_API_VERSION)
def test_create_ring(self):
hosts = ['foo', 'bar']
replicas = 2
ring = hash_ring.HashRing(hosts, replicas=replicas)
self.assertEqual(set(hosts), ring.hosts)
self.assertEqual(replicas, ring.replicas)
def test_get_hosts_invalid_data(self):
hosts = ['foo', 'bar']
ring = hash_ring.HashRing(hosts)
self.assertRaises(exception.Invalid, ring.get_hosts, None)
def test_ignore_non_existent_host(self):
hosts = ['foo', 'bar']
ring = hash_ring.HashRing(hosts, replicas=1)
self.assertEqual(['foo'], ring.get_hosts('fake', ignore_hosts=['baz']))
def test_more_replicas_than_hosts(self):
hosts = ['foo', 'bar']
ring = hash_ring.HashRing(hosts, replicas=10)
self.assertEqual(set(hosts), set(ring.get_hosts('fake')))
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'))
