Samuel Merritt 27dcaf2636 Spread handoffs out better around zones.
Before, you'd get your 3* primary nodes in 3 different zones, and then
get_more_nodes would give you everything it could from a non-primary
zone, and then finish up with stuff from the primary zones. It would
sort of look like this:

P: device in a primary node's zone
N: device not in a primary node's zone

PPPNNNNNNNNNNNNNNNNNNN...NNNNNNNNNPPP...PPPPPP

(The first three Ps are the primary nodes; they don't actually come
out of get_more_nodes(), but they're included for clarity.)

Now, the first few handoffs from get_more_nodes are in non-primary
zones, but only one per zone, and then the rest of the handoffs ignore
zones. It's still sampling the ring, so it's still taking weights into
consideration, but the zone distribution is more even early in the
handoff chain. It looks like this, assuming 10 zones:

P: device in a primary node's zone
N: device not in a primary node's zone
D: zone doesn't matter

PPPNNNNNNNDDDDDDDDDDD...DDD

* or whatever your replica count is

Change-Id: I31d2a2bc2cd6038386a2df85cd4fa37ccf2f650e
2013-03-05 13:28:12 -08:00

548 lines
24 KiB
Python

# 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.
import array
import cPickle as pickle
import os
import sys
import unittest
from gzip import GzipFile
from shutil import rmtree
from time import sleep, time
from swift.common import ring, utils
class TestRingData(unittest.TestCase):
def setUp(self):
self.testdir = os.path.join(os.path.dirname(__file__), 'ring_data')
rmtree(self.testdir, ignore_errors=1)
os.mkdir(self.testdir)
def tearDown(self):
rmtree(self.testdir, ignore_errors=1)
def assert_ring_data_equal(self, rd_expected, rd_got):
self.assertEquals(rd_expected._replica2part2dev_id,
rd_got._replica2part2dev_id)
self.assertEquals(rd_expected.devs, rd_got.devs)
self.assertEquals(rd_expected._part_shift, rd_got._part_shift)
def test_attrs(self):
r2p2d = [[0, 1, 0, 1], [0, 1, 0, 1]]
d = [{'id': 0, 'zone': 0}, {'id': 1, 'zone': 1}]
s = 30
rd = ring.RingData(r2p2d, d, s)
self.assertEquals(rd._replica2part2dev_id, r2p2d)
self.assertEquals(rd.devs, d)
self.assertEquals(rd._part_shift, s)
def test_can_load_pickled_ring_data(self):
rd = ring.RingData([[0, 1, 0, 1], [0, 1, 0, 1]],
[{'id': 0, 'zone': 0}, {'id': 1, 'zone': 1}], 30)
ring_fname = os.path.join(self.testdir, 'foo.ring.gz')
for p in xrange(pickle.HIGHEST_PROTOCOL):
pickle.dump(rd, GzipFile(ring_fname, 'wb'), protocol=p)
ring_data = ring.RingData.load(ring_fname)
self.assert_ring_data_equal(rd, ring_data)
def test_roundtrip_serialization(self):
ring_fname = os.path.join(self.testdir, 'foo.ring.gz')
rd = ring.RingData(
[array.array('H', [0, 1, 0, 1]), array.array('H',[0, 1, 0, 1])],
[{'id': 0, 'zone': 0}, {'id': 1, 'zone': 1}], 30)
rd.save(ring_fname)
rd2 = ring.RingData.load(ring_fname)
self.assert_ring_data_equal(rd, rd2)
def test_deterministic_serialization(self):
"""
Two identical rings should produce identical .gz files on disk.
Only true on Python 2.7 or greater.
"""
if sys.version_info[0] == 2 and sys.version_info[1] < 7:
return
os.mkdir(os.path.join(self.testdir, '1'))
os.mkdir(os.path.join(self.testdir, '2'))
# These have to have the same filename (not full path,
# obviously) since the filename gets encoded in the gzip data.
ring_fname1 = os.path.join(self.testdir, '1', 'the.ring.gz')
ring_fname2 = os.path.join(self.testdir, '2', 'the.ring.gz')
rd = ring.RingData(
[array.array('H', [0, 1, 0, 1]), array.array('H',[0, 1, 0, 1])],
[{'id': 0, 'zone': 0}, {'id': 1, 'zone': 1}], 30)
rd.save(ring_fname1)
rd.save(ring_fname2)
with open(ring_fname1) as ring1:
with open(ring_fname2) as ring2:
self.assertEqual(ring1.read(), ring2.read())
class TestRing(unittest.TestCase):
def setUp(self):
utils.HASH_PATH_SUFFIX = 'endcap'
self.testdir = os.path.join(os.path.dirname(__file__), 'ring')
rmtree(self.testdir, ignore_errors=1)
os.mkdir(self.testdir)
self.testgz = os.path.join(self.testdir, 'whatever.ring.gz')
self.intended_replica2part2dev_id = [
array.array('H', [0, 1, 0, 1]),
array.array('H', [0, 1, 0, 1]),
array.array('H', [3, 4, 3, 4])]
self.intended_devs = [{'id': 0, 'zone': 0, 'weight': 1.0,
'ip': '10.1.1.1', 'port': 6000},
{'id': 1, 'zone': 0, 'weight': 1.0,
'ip': '10.1.1.1', 'port': 6000},
None,
{'id': 3, 'zone': 2, 'weight': 1.0,
'ip': '10.1.2.1', 'port': 6000},
{'id': 4, 'zone': 2, 'weight': 1.0,
'ip': '10.1.2.2', 'port': 6000}]
self.intended_part_shift = 30
self.intended_reload_time = 15
ring.RingData(self.intended_replica2part2dev_id,
self.intended_devs, self.intended_part_shift).save(self.testgz)
self.ring = ring.Ring(self.testdir,
reload_time=self.intended_reload_time, ring_name='whatever')
def tearDown(self):
rmtree(self.testdir, ignore_errors=1)
def test_creation(self):
self.assertEquals(self.ring._replica2part2dev_id,
self.intended_replica2part2dev_id)
self.assertEquals(self.ring._part_shift, self.intended_part_shift)
self.assertEquals(self.ring.devs, self.intended_devs)
self.assertEquals(self.ring.reload_time, self.intended_reload_time)
self.assertEquals(self.ring.serialized_path, self.testgz)
# test invalid endcap
_orig_hash_path_suffix = utils.HASH_PATH_SUFFIX
try:
utils.HASH_PATH_SUFFIX = ''
self.assertRaises(SystemExit, ring.Ring, self.testdir, 'whatever')
finally:
utils.HASH_PATH_SUFFIX = _orig_hash_path_suffix
def test_has_changed(self):
self.assertEquals(self.ring.has_changed(), False)
os.utime(self.testgz, (time() + 60, time() + 60))
self.assertEquals(self.ring.has_changed(), True)
def test_reload(self):
os.utime(self.testgz, (time() - 300, time() - 300))
self.ring = ring.Ring(self.testdir, reload_time=0.001,
ring_name='whatever')
orig_mtime = self.ring._mtime
self.assertEquals(len(self.ring.devs), 5)
self.intended_devs.append({'id': 3, 'zone': 3, 'weight': 1.0})
ring.RingData(self.intended_replica2part2dev_id,
self.intended_devs, self.intended_part_shift).save(self.testgz)
sleep(0.1)
self.ring.get_nodes('a')
self.assertEquals(len(self.ring.devs), 6)
self.assertNotEquals(self.ring._mtime, orig_mtime)
os.utime(self.testgz, (time() - 300, time() - 300))
self.ring = ring.Ring(self.testdir, reload_time=0.001,
ring_name='whatever')
orig_mtime = self.ring._mtime
self.assertEquals(len(self.ring.devs), 6)
self.intended_devs.append({'id': 5, 'zone': 4, 'weight': 1.0})
ring.RingData(self.intended_replica2part2dev_id,
self.intended_devs, self.intended_part_shift).save(self.testgz)
sleep(0.1)
self.ring.get_part_nodes(0)
self.assertEquals(len(self.ring.devs), 7)
self.assertNotEquals(self.ring._mtime, orig_mtime)
os.utime(self.testgz, (time() - 300, time() - 300))
self.ring = ring.Ring(self.testdir, reload_time=0.001,
ring_name='whatever')
orig_mtime = self.ring._mtime
part, nodes = self.ring.get_nodes('a')
self.assertEquals(len(self.ring.devs), 7)
self.intended_devs.append({'id': 6, 'zone': 5, 'weight': 1.0})
ring.RingData(self.intended_replica2part2dev_id,
self.intended_devs, self.intended_part_shift).save(self.testgz)
sleep(0.1)
self.ring.get_more_nodes(part).next()
self.assertEquals(len(self.ring.devs), 8)
self.assertNotEquals(self.ring._mtime, orig_mtime)
os.utime(self.testgz, (time() - 300, time() - 300))
self.ring = ring.Ring(self.testdir, reload_time=0.001,
ring_name='whatever')
orig_mtime = self.ring._mtime
self.assertEquals(len(self.ring.devs), 8)
self.intended_devs.append({'id': 5, 'zone': 4, 'weight': 1.0})
ring.RingData(self.intended_replica2part2dev_id,
self.intended_devs, self.intended_part_shift).save(self.testgz)
sleep(0.1)
self.assertEquals(len(self.ring.devs), 9)
self.assertNotEquals(self.ring._mtime, orig_mtime)
def test_get_part_nodes(self):
part, nodes = self.ring.get_nodes('a')
self.assertEquals(nodes, self.ring.get_part_nodes(part))
def test_get_nodes(self):
# Yes, these tests are deliberately very fragile. We want to make sure
# that if someones changes the results the ring produces, they know it.
self.assertRaises(TypeError, self.ring.get_nodes)
part, nodes = self.ring.get_nodes('a')
self.assertEquals(part, 0)
self.assertEquals(nodes, [self.intended_devs[0],
self.intended_devs[3]])
part, nodes = self.ring.get_nodes('a1')
self.assertEquals(part, 0)
self.assertEquals(nodes, [self.intended_devs[0],
self.intended_devs[3]])
part, nodes = self.ring.get_nodes('a4')
self.assertEquals(part, 1)
self.assertEquals(nodes, [self.intended_devs[1],
self.intended_devs[4]])
part, nodes = self.ring.get_nodes('aa')
self.assertEquals(part, 1)
self.assertEquals(nodes, [self.intended_devs[1],
self.intended_devs[4]])
part, nodes = self.ring.get_nodes('a', 'c1')
self.assertEquals(part, 0)
self.assertEquals(nodes, [self.intended_devs[0],
self.intended_devs[3]])
part, nodes = self.ring.get_nodes('a', 'c0')
self.assertEquals(part, 3)
self.assertEquals(nodes, [self.intended_devs[1],
self.intended_devs[4]])
part, nodes = self.ring.get_nodes('a', 'c3')
self.assertEquals(part, 2)
self.assertEquals(nodes, [self.intended_devs[0],
self.intended_devs[3]])
part, nodes = self.ring.get_nodes('a', 'c2')
self.assertEquals(part, 2)
self.assertEquals(nodes, [self.intended_devs[0],
self.intended_devs[3]])
part, nodes = self.ring.get_nodes('a', 'c', 'o1')
self.assertEquals(part, 1)
self.assertEquals(nodes, [self.intended_devs[1],
self.intended_devs[4]])
part, nodes = self.ring.get_nodes('a', 'c', 'o5')
self.assertEquals(part, 0)
self.assertEquals(nodes, [self.intended_devs[0],
self.intended_devs[3]])
part, nodes = self.ring.get_nodes('a', 'c', 'o0')
self.assertEquals(part, 0)
self.assertEquals(nodes, [self.intended_devs[0],
self.intended_devs[3]])
part, nodes = self.ring.get_nodes('a', 'c', 'o2')
self.assertEquals(part, 2)
self.assertEquals(nodes, [self.intended_devs[0],
self.intended_devs[3]])
def add_dev_to_ring(self, new_dev):
self.ring.devs.append(new_dev)
self.ring._rebuild_tier_data()
def test_get_more_nodes(self):
# Yes, these tests are deliberately very fragile. We want to make sure
# that if someone changes the results the ring produces, they know it.
exp_part = 6
exp_devs = [48, 93, 96]
exp_zones = set([5, 8, 9])
exp_handoffs = [11, 47, 25, 76, 69, 23, 99, 59, 106, 64, 107, 43, 50,
34, 88, 3, 57, 30, 83, 31, 16, 27, 103, 39, 32, 60, 77,
24, 0, 42, 8, 100, 72, 56, 19, 71, 26, 9, 20, 35, 91,
13, 84, 5, 38, 14, 94, 28, 41, 18, 66, 102, 52, 101,
61, 95, 21, 81, 1, 78, 105, 58, 74, 90, 86, 46, 4, 68,
40, 80, 54, 75, 45, 79, 44, 49, 62, 29, 7, 15, 70, 87,
65, 12, 82, 17, 104, 97, 55, 22, 6, 89, 2, 67, 37, 63,
53, 92, 33, 85, 73, 51, 98, 36, 10]
exp_first_handoffs = [1, 37, 48, 68, 84, 75, 11, 101, 14, 73, 100, 75,
29, 19, 18, 101, 15, 99, 95, 24, 46, 82, 73, 62,
24, 89, 9, 22, 107, 74, 54, 63, 40, 106, 99, 83,
64, 73, 73, 106, 106, 80, 6, 25, 20, 33, 6, 79,
59, 42, 62, 24, 14, 107, 28, 0, 85, 5, 4, 12, 58,
11, 92, 18, 36, 56, 86, 1, 21, 33, 80, 97, 4, 81,
79, 76, 89, 50, 75, 27, 7, 96, 47, 55, 81, 104,
12, 5, 18, 106, 27, 93, 39, 92, 42, 30, 20, 88,
58, 105, 65, 29, 17, 52, 11, 106, 7, 24, 21, 91,
62, 52, 50, 31, 77, 102, 19, 11, 8, 58, 53, 20,
26, 8, 18, 82, 48, 68, 82, 89, 101, 50, 3, 52,
46, 11, 2, 30, 79, 66, 4, 61, 3, 56, 45, 102, 73,
84, 36, 19, 34, 84, 49, 40, 103, 66, 31, 33, 93,
33, 4, 52, 26, 58, 30, 47, 100, 57, 40, 79, 33,
107, 24, 20, 44, 4, 7, 59, 83, 101, 1, 56, 20,
61, 33, 16, 5, 74, 98, 4, 80, 15, 104, 52, 73,
18, 67, 75, 98, 73, 79, 68, 75, 27, 91, 36, 100,
52, 95, 37, 46, 70, 14, 47, 3, 70, 23, 40, 105,
62, 86, 48, 22, 54, 4, 72, 81, 13, 0, 18, 98,
101, 36, 29, 24, 39, 79, 97, 105, 28, 107, 47,
52, 101, 20, 22, 29, 65, 27, 7, 33, 64, 101, 60,
19, 55]
rb = ring.RingBuilder(8, 3, 1)
next_dev_id = 0
for zone in xrange(1, 10):
for server in xrange(1, 5):
for device in xrange(1, 4):
rb.add_dev({'id': next_dev_id,
'ip': '1.2.%d.%d' % (zone, server),
'port': 1234, 'zone': zone, 'weight': 1.0})
next_dev_id += 1
rb.rebalance(seed=1)
rb.get_ring().save(self.testgz)
r = ring.Ring(self.testdir, ring_name='whatever')
part, devs = r.get_nodes('a', 'c', 'o')
primary_zones = set(d['zone'] for d in devs)
self.assertEquals(part, exp_part)
self.assertEquals([d['id'] for d in devs], exp_devs)
self.assertEquals(primary_zones, exp_zones)
devs = list(r.get_more_nodes(part))
self.assertEquals([d['id'] for d in devs], exp_handoffs)
seen_shared_zone = False
# The first 6 replicas plus the 3 primary nodes should cover all 9
# zones in this test
seen_zones = set(primary_zones)
seen_zones.update(d['zone'] for d in devs[:6])
self.assertEquals(seen_zones, set(range(1, 10)))
# The first handoff nodes for each partition in the ring
devs = []
for part in xrange(r.partition_count):
devs.append(r.get_more_nodes(part).next()['id'])
self.assertEquals(devs, exp_first_handoffs)
# Add a new device we can handoff to.
zone = 5
server = 0
rb.add_dev({'id': next_dev_id,
'ip': '1.2.%d.%d' % (zone, server),
'port': 1234, 'zone': zone, 'weight': 1.0})
next_dev_id += 1
rb.rebalance(seed=1)
rb.get_ring().save(self.testgz)
r = ring.Ring(self.testdir, ring_name='whatever')
# We would change expectations here, but in this test no handoffs
# changed at all.
part, devs = r.get_nodes('a', 'c', 'o')
primary_zones = set(d['zone'] for d in devs)
self.assertEquals(part, exp_part)
self.assertEquals([d['id'] for d in devs], exp_devs)
self.assertEquals(primary_zones, exp_zones)
devs = list(r.get_more_nodes(part))
dev_ids = [d['id'] for d in devs]
self.assertEquals(len(dev_ids), len(exp_handoffs))
for index, dev in enumerate(dev_ids):
self.assertEquals(
dev, exp_handoffs[index],
'handoff differs at position %d\n%s\n%s' % (
index, dev_ids[index:], exp_handoffs[index:]))
# The handoffs still cover all the non-primary zones first
seen_zones = set(primary_zones)
seen_zones.update(d['zone'] for d in devs[:6])
self.assertEquals(seen_zones, set(range(1, 10)))
devs = []
for part in xrange(r.partition_count):
devs.append(r.get_more_nodes(part).next()['id'])
for part in xrange(r.partition_count):
self.assertEquals(
devs[part], exp_first_handoffs[part],
'handoff for partitition %d is now device id %d' % (
part, devs[part]))
# Remove a device.
rb.remove_dev(0)
rb.rebalance(seed=1)
rb.get_ring().save(self.testgz)
r = ring.Ring(self.testdir, ring_name='whatever')
# Change expectations
# The long string of handoff nodes for the partition were the same for
# the first 20, which is pretty good.
exp_handoffs[20:] = [16, 27, 103, 39, 32, 60, 77, 24, 108, 42, 8, 100,
72, 56, 19, 71, 26, 9, 20, 35, 91, 13, 84, 5, 38,
14, 94, 28, 41, 18, 66, 102, 52, 101, 61, 95, 21,
81, 1, 78, 105, 58, 74, 90, 86, 46, 4, 68, 40, 80,
54, 75, 45, 79, 44, 49, 62, 29, 7, 15, 70, 87, 65,
12, 82, 17, 104, 97, 55, 22, 6, 89, 2, 67, 37, 63,
53, 92, 33, 85, 73, 51, 98, 36, 10]
# Just a few of the first handoffs changed
exp_first_handoffs[3] = 68
exp_first_handoffs[55] = 104
exp_first_handoffs[116] = 6
exp_first_handoffs[181] = 15
exp_first_handoffs[228] = 38
# Test
part, devs = r.get_nodes('a', 'c', 'o')
primary_zones = set(d['zone'] for d in devs)
self.assertEquals(part, exp_part)
self.assertEquals([d['id'] for d in devs], exp_devs)
self.assertEquals(primary_zones, exp_zones)
devs = list(r.get_more_nodes(part))
dev_ids = [d['id'] for d in devs]
self.assertEquals(len(dev_ids), len(exp_handoffs))
for index, dev in enumerate(dev_ids):
self.assertEquals(
dev, exp_handoffs[index],
'handoff differs at position %d\n%s\n%s' % (
index, dev_ids[index:], exp_handoffs[index:]))
seen_zones = set(primary_zones)
seen_zones.update(d['zone'] for d in devs[:6])
self.assertEquals(seen_zones, set(range(1, 10)))
devs = []
for part in xrange(r.partition_count):
devs.append(r.get_more_nodes(part).next()['id'])
for part in xrange(r.partition_count):
self.assertEquals(
devs[part], exp_first_handoffs[part],
'handoff for partitition %d is now device id %d' % (
part, devs[part]))
# Add a partial replica
rb.set_replicas(3.5)
rb.rebalance(seed=1)
rb.get_ring().save(self.testgz)
r = ring.Ring(self.testdir, ring_name='whatever')
# Change expectations
# We have another replica now
exp_devs.append(47)
exp_zones.add(4)
# Caused some major changes in the sequence of handoffs for our test
# partition, but at least the first stayed the same.
exp_handoffs[1:] = [81, 25, 69, 23, 99, 59, 76, 3, 106, 45, 64, 107,
43, 13, 50, 34, 88, 57, 30, 16, 83, 31, 46, 27,
103, 39, 74, 32, 60, 77, 24, 108, 42, 63, 8, 100,
72, 56, 19, 71, 7, 26, 9, 20, 35, 91, 52, 84, 5,
87, 38, 14, 94, 62, 28, 41, 90, 18, 66, 82, 102,
22, 101, 61, 85, 95, 21, 98, 1, 67, 78, 105, 58,
86, 4, 79, 68, 40, 80, 54, 75, 44, 49, 6, 29, 15,
70, 65, 12, 17, 104, 97, 55, 89, 2, 37, 53, 92,
33, 73, 51, 36, 10]
# Lots of first handoffs changed, but 30 of 256 is still just 11.72%.
exp_first_handoffs[1] = 6
exp_first_handoffs[4] = 104
exp_first_handoffs[11] = 106
exp_first_handoffs[17] = 13
exp_first_handoffs[21] = 77
exp_first_handoffs[22] = 95
exp_first_handoffs[27] = 46
exp_first_handoffs[29] = 65
exp_first_handoffs[30] = 3
exp_first_handoffs[31] = 20
exp_first_handoffs[51] = 50
exp_first_handoffs[53] = 8
exp_first_handoffs[54] = 2
exp_first_handoffs[72] = 107
exp_first_handoffs[79] = 72
exp_first_handoffs[85] = 71
exp_first_handoffs[88] = 66
exp_first_handoffs[92] = 29
exp_first_handoffs[93] = 46
exp_first_handoffs[96] = 38
exp_first_handoffs[101] = 57
exp_first_handoffs[103] = 87
exp_first_handoffs[104] = 28
exp_first_handoffs[107] = 1
exp_first_handoffs[109] = 69
exp_first_handoffs[110] = 50
exp_first_handoffs[111] = 76
exp_first_handoffs[115] = 47
exp_first_handoffs[117] = 48
exp_first_handoffs[119] = 7
# Test
part, devs = r.get_nodes('a', 'c', 'o')
primary_zones = set(d['zone'] for d in devs)
self.assertEquals(part, exp_part)
self.assertEquals([d['id'] for d in devs], exp_devs)
self.assertEquals(primary_zones, exp_zones)
devs = list(r.get_more_nodes(part))
dev_ids = [d['id'] for d in devs]
self.assertEquals(len(dev_ids), len(exp_handoffs))
for index, dev in enumerate(dev_ids):
self.assertEquals(
dev, exp_handoffs[index],
'handoff differs at position %d\n%s\n%s' % (
index, dev_ids[index:], exp_handoffs[index:]))
seen_zones = set(primary_zones)
seen_zones.update(d['zone'] for d in devs[:6])
self.assertEquals(seen_zones, set(range(1, 10)))
devs = []
for part in xrange(r.partition_count):
devs.append(r.get_more_nodes(part).next()['id'])
for part in xrange(r.partition_count):
self.assertEquals(
devs[part], exp_first_handoffs[part],
'handoff for partitition %d is now device id %d' % (
part, devs[part]))
# One last test of a partial replica partition
exp_part2 = 136
exp_devs2 = [52, 76, 97]
exp_zones2 = set([9, 5, 7])
exp_handoffs2 = [2, 67, 37, 92, 33, 23, 107, 96, 63, 53, 44, 103, 108,
85, 73, 51, 42, 98, 35, 36, 10, 89, 80, 84, 43, 4, 17,
49, 104, 32, 12, 41, 58, 31, 65, 20, 25, 61, 1, 40, 9,
94, 47, 69, 56, 74, 101, 95, 45, 5, 71, 86, 78, 30, 93,
48, 28, 91, 15, 88, 39, 18, 57, 83, 72, 70, 27, 54, 16,
24, 21, 14, 11, 8, 77, 62, 50, 6, 105, 26, 55, 29, 60,
34, 13, 87, 59, 38, 99, 75, 106, 3, 82, 66, 79, 7, 46,
64, 81, 22, 68, 19, 102, 90, 100]
part2, devs2 = r.get_nodes('a', 'c', 'o2')
primary_zones2 = set(d['zone'] for d in devs2)
self.assertEquals(part2, exp_part2)
self.assertEquals([d['id'] for d in devs2], exp_devs2)
self.assertEquals(primary_zones2, exp_zones2)
devs2 = list(r.get_more_nodes(part2))
dev_ids2 = [d['id'] for d in devs2]
self.assertEquals(len(dev_ids2), len(exp_handoffs2))
for index, dev in enumerate(dev_ids2):
self.assertEquals(
dev, exp_handoffs2[index],
'handoff differs at position %d\n%s\n%s' % (
index, dev_ids2[index:], exp_handoffs2[index:]))
seen_zones = set(primary_zones2)
seen_zones.update(d['zone'] for d in devs2[:6])
self.assertEquals(seen_zones, set(range(1, 10)))
if __name__ == '__main__':
unittest.main()