openstack/swift
Code Issues Proposed changes

Shuffle the partitions to reassign on a ring rebalance.

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This commit is contained in:
gholt 2011-01-13 09:05:44 -08:00
parent 2962557612
commit d6aaba670b
2 changed files with 37 additions and 1 deletions
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3
swift/common/ring/builder.py
View File

@ -14,7 +14,7 @@
# limitations under the License.
from array import array
from random import randint
from random import randint, shuffle
from time import time
from swift.common.ring import RingData
@ -413,6 +413,7 @@ class RingBuilder(object):
dev['parts_wanted'] += 1
dev['parts'] -= 1
reassign_parts.append(part)
shuffle(reassign_parts)
return reassign_parts
def _reassign_parts(self, reassign_parts):

35
test/unit/common/ring/test_builder.py
View File

@ -125,6 +125,41 @@ class TestRingBuilder(unittest.TestCase):
counts[dev_id] = counts.get(dev_id, 0) + 1
self.assertEquals(counts, {0: 256, 2: 256, 3: 256})
def test_shuffled_gather(self):
if self._shuffled_gather_helper() and \
self._shuffled_gather_helper():
raise AssertionError('It is highly likely the ring is no '
'longer shuffling the set of partitions to reassign on a '
'rebalance.')
def _shuffled_gather_helper(self):
rb = ring.RingBuilder(8, 3, 1)
rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
'port': 10000, 'device': 'sda1'})
rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
'port': 10001, 'device': 'sda1'})
rb.add_dev({'id': 2, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
'port': 10002, 'device': 'sda1'})
rb.rebalance()
rb.add_dev({'id': 3, 'zone': 3, 'weight': 1, 'ip': '127.0.0.1',
'port': 10003, 'device': 'sda1'})
rb.pretend_min_part_hours_passed()
parts = rb._gather_reassign_parts()
max_run = 0
run = 0
last_part = 0
for part in parts:
if part > last_part:
run += 1
else:
if run > max_run:
max_run = run
run = 0
last_part = part
if run > max_run:
max_run = run
return max_run > len(parts) / 2
def test_rerebalance(self):
rb = ring.RingBuilder(8, 3, 1)
rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',