openstack/swift
Code Issues Proposed changes

Merge "sharder: only shrink to root if all ranges are involved"

Browse Source
This commit is contained in:
Zuul 2021-03-15 19:30:06 +00:00 committed by Gerrit Code Review
commit 2db4667759
2 changed files with 46 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
swift/container/sharder.py
View File

@ -261,16 +261,16 @@ def find_compactible_shard_sequences(broker,
index += len(sequence)
if (index == len(shard_ranges) and
not compactible_sequences and
len(shard_ranges) == len(sequence) and
not sequence_complete(sequence) and
sequence.includes(own_shard_range)):
# special case: only one sequence has been found, which encompasses
# the entire namespace, has no more than merge_size records and
# whose shard ranges are all shrinkable; all the shards in the
# sequence can be shrunk to the root, so append own_shard_range to
# the sequence to act as an acceptor; note: only shrink to the root
# when *all* the remaining shard ranges can be simultaneously
# shrunk to the root.
# special case: only one sequence has been found, which consumes
# all shard ranges, encompasses the entire namespace, has no more
# than merge_size records and whose shard ranges are all
# shrinkable; all the shards in the sequence can be shrunk to the
# root, so append own_shard_range to the sequence to act as an
# acceptor; note: only shrink to the root when *all* the remaining
# shard ranges can be simultaneously shrunk to the root.
sequence.append(own_shard_range)
if len(sequence) < 2 or sequence[-1].state not in (ShardRange.ACTIVE,

39
test/unit/container/test_sharder.py
View File

@ -6517,11 +6517,23 @@ class TestSharderFunctions(BaseTestSharder):
sequences = find_compactible_shard_sequences(broker, 20, 19, -1, -1)
self.assertEqual([], sequences)
def test_find_compactible_nine_donors_one_acceptor(self):
# one sequence that spans entire namespace but does not shrink to root
broker = self._make_broker()
shard_ranges = self._make_shard_ranges(
(('', 'b'), ('b', 'c'), ('c', 'd'), ('d', 'e'), ('e', 'f'),
('f', 'g'), ('g', 'h'), ('h', 'i'), ('i', 'j'), ('j', '')),
state=ShardRange.ACTIVE)
shard_ranges[9].object_count = 11 # final shard too big to shrink
broker.merge_shard_ranges(shard_ranges)
sequences = find_compactible_shard_sequences(broker, 10, 999, -1, -1)
self.assertEqual([shard_ranges], sequences)
def test_find_compactible_four_donors_two_acceptors(self):
small_ranges = (2, 3, 4, 7)
broker = self._make_broker()
shard_ranges = self._make_shard_ranges(
(('a', 'b'), ('b', 'c'), ('c', 'd'), ('d', 'e'), ('e', 'f'),
(('', 'b'), ('b', 'c'), ('c', 'd'), ('d', 'e'), ('e', 'f'),
('f', 'g'), ('g', 'h'), ('h', 'i'), ('i', 'j'), ('j', '')),
state=ShardRange.ACTIVE)
for i, sr in enumerate(shard_ranges):
@ -6571,6 +6583,31 @@ class TestSharderFunctions(BaseTestSharder):
include_shrinking=True)
self.assertEqual([shard_ranges + [own_sr]], sequences)
def test_find_compactible_overlapping_ranges(self):
# unexpected case: all shrinkable, two overlapping sequences, one which
# spans entire namespace; should not shrink to root
broker = self._make_broker()
shard_ranges = self._make_shard_ranges(
(('', 'b'), ('b', 'c'), # overlaps form one sequence
('', 'j'), ('j', '')), # second sequence spans entire namespace
state=ShardRange.ACTIVE)
shard_ranges[1].object_count = 11 # cannot shrink, so becomes acceptor
broker.merge_shard_ranges(shard_ranges)
sequences = find_compactible_shard_sequences(broker, 10, 999, -1, -1)
self.assertEqual([shard_ranges[:2], shard_ranges[2:]], sequences)
def test_find_compactible_overlapping_ranges_with_ineligible_state(self):
# unexpected case: one ineligible state shard range overlapping one
# sequence which spans entire namespace; should not shrink to root
broker = self._make_broker()
shard_ranges = self._make_shard_ranges(
(('', 'b'), # overlap in ineligible state
('', 'j'), ('j', '')), # sequence spans entire namespace
state=[ShardRange.CREATED, ShardRange.ACTIVE, ShardRange.ACTIVE])
broker.merge_shard_ranges(shard_ranges)
sequences = find_compactible_shard_sequences(broker, 10, 999, -1, -1)
self.assertEqual([shard_ranges[1:]], sequences)
def test_find_compactible_donors_but_no_suitable_acceptor(self):
# if shard ranges are already shrinking, check that the final one is
# not made into an acceptor if a suitable adjacent acceptor is not