openstack/swift
Code Issues Proposed changes

Make test_get_more_nodes_with_zero_weight_region more robust

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...by using a random ring, looking at *all* partitions, and making
assertions about the distribution of how many times we have to call
next().

Change-Id: Ia5feb9396d4bf6fd35f16bbc5280e63022ed2c47
This commit is contained in:
Tim Burke 2017-01-09 20:00:33 +00:00
parent bf09a06708
commit 0d4d940243
1 changed files with 36 additions and 8 deletions
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44
test/unit/common/ring/test_ring.py
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@ -14,6 +14,7 @@
# limitations under the License.
import array
import collections
import six.moves.cPickle as pickle
import os
import unittest
@ -23,7 +24,6 @@ from gzip import GzipFile
from tempfile import mkdtemp
from shutil import rmtree
from time import sleep, time
import random
import sys
import copy
import mock
@ -35,6 +35,7 @@ from swift.common.ring import utils as ring_utils
class TestRingBase(unittest.TestCase):
longMessage = True
def setUp(self):
self._orig_hash_suffix = utils.HASH_PATH_SUFFIX
@ -874,7 +875,7 @@ class TestRing(TestRingBase):
else:
dev['weight'] = 1.0
rb.add_dev(dev)
rb.rebalance(seed=1)
rb.rebalance()
rb.get_ring().save(self.testgz)
r = ring.Ring(self.testdir, ring_name='whatever')
@ -898,16 +899,43 @@ class TestRing(TestRingBase):
def __getitem__(self, key):
return self.table[key]
counting_table = CountingRingTable(r._replica2part2dev_id)
r._replica2part2dev_id = counting_table
histogram = collections.defaultdict(int)
for part in range(r.partition_count):
counting_table = CountingRingTable(r._replica2part2dev_id)
with mock.patch.object(r, '_replica2part2dev_id', counting_table):
node_iter = r.get_more_nodes(part)
next(node_iter)
histogram[counting_table.count] += 1
# Don't let our summing muddy our histogram
histogram = dict(histogram)
part = random.randint(0, r.partition_count)
node_iter = r.get_more_nodes(part)
next(node_iter)
self.assertLess(counting_table.count, 14)
# sanity
self.assertEqual(1, r._num_regions)
self.assertEqual(2, r._num_zones)
self.assertEqual(256, r.partition_count)
# We always do one loop (including the StopIteration) while getting
# primaries, so every part should hit next() at least 5 times
self.assertEqual(sum(histogram.get(x, 0) for x in range(5)), 0,
histogram)
# Most of the parts should find a handoff device in the next partition,
# but because some of the primary devices may *also* be used for that
# partition, that means 5, 6, or 7 calls to next().
self.assertGreater(sum(histogram.get(x, 0) for x in range(8)), 160,
histogram)
# Want 90% confidence that it'll happen within two partitions
self.assertGreater(sum(histogram.get(x, 0) for x in range(12)), 230,
histogram)
# Tail should fall off fairly quickly
self.assertLess(sum(histogram.get(x, 0) for x in range(20, 100)), 5,
histogram)
# Hard limit at 50 (we've seen as bad as 41, 45)
self.assertEqual(sum(histogram.get(x, 0) for x in range(50, 100)), 0,
histogram)
if __name__ == '__main__':