Merge "Fix unbalanced rings after initial creation."

openstack/swift

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2013年09月09日 22:57:15 +00:00

committed by Gerrit Code Review

parent 6cd3029dae d3e2cb35db

commit 00a31f5f15

3 changed files with 54 additions and 18 deletions

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43
swift/common/ring/builder.py

View File

@@ -332,7 +332,7 @@ class RingBuilder(object):

:returns: (number_of_partitions_altered, resulting_balance)

"""

if seed:

if seed is not None:

random.seed(seed)

self._ring = None

@@ -821,26 +821,35 @@ class RingBuilder(object):

#

# This used to be a cute, recursive function, but it's been

# unrolled for performance.

candidate_tiers = tier2children[tier]

# We sort the tiers here so that, when we look for a tier

# with the lowest number of replicas, the first one we

# find is the one with the hungriest drive (i.e. drive

# with the largest sort_key value). This lets us

# short-circuit the search while still ensuring we get the

# right tier.

candidate_tiers = sorted(

tier2children[tier],

key=lambda tier: tier2devs[tier][-1]['sort_key'],

reverse=True)

candidates_with_replicas = \

unique_tiers_by_tier_len[len(tier) + 1]

if len(candidate_tiers) > len(candidates_with_replicas):

# There exists at least one tier with 0 other replicas,

# so work backward among the candidates, accepting the

# first which isn't in other_replicas.

#

# This optimization is to avoid calling the min()

# below, which is expensive if you've got thousands of

# drives.

for t in reversed(candidate_tiers):

if other_replicas[t] == 0:

tier = t

break

# There exists at least one tier with 0 other

# replicas, so avoid calling the min() below, which is

# expensive if you've got thousands of drives.

min_replica_count = 0

else:

min_count = min(other_replicas[t]

for t in candidate_tiers)

tier = (t for t in reversed(candidate_tiers)

if other_replicas[t] == min_count).next()

min_replica_count = min(other_replicas[t]

for t in candidate_tiers)

# Find the first tier with the minimal replica count.

# Since they're sorted, this will also have the hungriest

# drive among all the tiers with the minimal replica

# count.

for t in candidate_tiers:

if other_replicas[t] == min_replica_count:

tier = t

break

depth += 1

dev = tier2devs[tier][-1]

dev['parts_wanted'] -= 1

2
swift/proxy/controllers/base.py

View File

@@ -382,7 +382,7 @@ def get_info(app, env, account, container=None, ret_not_found=False):

if ret_not_found or is_success(info['status']):

return info

return None

# Not in cached, let's try the account servers

# Not in cache, let's try the account servers

path = '/v1/%s' % account

if container:

# Stop and check if we have an account?

27
test/unit/common/ring/test_builder.py

View File

@@ -258,6 +258,33 @@ class TestRingBuilder(unittest.TestCase):

max_run = run

return max_run > len(parts) / 2

def test_initial_balance(self):

# 2 boxes, 2 drives each in zone 1

# 1 box, 2 drives in zone 2

#

# This is balanceable, but there used to be some nondeterminism in

# rebalance() that would sometimes give you an imbalanced ring.

rb = ring.RingBuilder(8, 3, 1)

rb.add_dev({'region': 1, 'zone': 1, 'weight': 4000.0,

'ip': '10.1.1.1', 'port': 10000, 'device': 'sda'})

rb.add_dev({'region': 1, 'zone': 1, 'weight': 4000.0,

'ip': '10.1.1.1', 'port': 10000, 'device': 'sdb'})

rb.add_dev({'region': 1, 'zone': 1, 'weight': 4000.0,

'ip': '10.1.1.2', 'port': 10000, 'device': 'sda'})

rb.add_dev({'region': 1, 'zone': 1, 'weight': 4000.0,

'ip': '10.1.1.2', 'port': 10000, 'device': 'sdb'})

rb.add_dev({'region': 1, 'zone': 2, 'weight': 4000.0,

'ip': '10.1.1.3', 'port': 10000, 'device': 'sda'})

rb.add_dev({'region': 1, 'zone': 2, 'weight': 4000.0,

'ip': '10.1.1.3', 'port': 10000, 'device': 'sdb'})

_, balance = rb.rebalance(seed=2)

# maybe not *perfect*, but should be close

self.assert_(balance <= 1)

def test_multitier_partial(self):

# Multitier test, nothing full

rb = ring.RingBuilder(8, 3, 1)