openstack/swift
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Merge "Fix RingBuilder._build_max_replicas_by_tier docstring"

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Jenkins 2014-09-13 13:05:52 +00:00 committed by Gerrit Code Review
commit 61e2b5235a
1 changed files with 35 additions and 28 deletions
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63
swift/common/ring/builder.py
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@ -942,39 +942,46 @@ class RingBuilder(object):
There will always be a () entry as the root of the structure, whose
replica_count will equal the ring's replica_count.
Then there will be (dev_id,) entries for each device, indicating the
maximum number of replicas the device might have for any given
partition. Anything greater than 1 indicates a partition at serious
risk, as the data on that partition will not be stored distinctly at
the ring's replica_count.
Then there will be (region,) entries for each region, indicating the
maximum number of replicas the region might have for any given
partition.
Next there will be (dev_id, ip_port) entries for each device,
indicating the maximum number of replicas the device shares with other
devices on the same ip_port for any given partition. Anything greater
than 1 indicates a partition at elevated risk, as if that ip_port were
to fail multiple replicas of that partition would be unreachable.
Next there will be (region, zone) entries for each zone, indicating
the maximum number of replicas in a given region and zone. Anything
greater than 1 indicates a partition at slightly elevated risk, as if
that zone were to fail multiple replicas of that partition would be
unreachable.
Last there will be (dev_id, ip_port, zone) entries for each device,
indicating the maximum number of replicas the device shares with other
devices within the same zone for any given partition. Anything greater
than 1 indicates a partition at slightly elevated risk, as if that zone
were to fail multiple replicas of that partition would be unreachable.
Next there will be (region, zone, ip_port) entries for each node,
indicating the maximum number of replicas stored on a node in a given
region and zone. Anything greater than 1 indicates a partition at
elevated risk, as if that ip_port were to fail multiple replicas of
that partition would be unreachable.
Last there will be (region, zone, ip_port, device) entries for each
device, indicating the maximum number of replicas the device shares
with other devices on the same node for any given partition.
Anything greater than 1 indicates a partition at serious risk, as the
data on that partition will not be stored distinctly at the ring's
replica_count.
Example return dict for the common SAIO setup::
{(): 3,
(1,): 1.0,
(1, '127.0.0.1:6010'): 1.0,
(1, '127.0.0.1:6010', 0): 1.0,
(2,): 1.0,
(2, '127.0.0.1:6020'): 1.0,
(2, '127.0.0.1:6020', 1): 1.0,
(3,): 1.0,
(3, '127.0.0.1:6030'): 1.0,
(3, '127.0.0.1:6030', 2): 1.0,
(4,): 1.0,
(4, '127.0.0.1:6040'): 1.0,
(4, '127.0.0.1:6040', 3): 1.0}
{(): 3.0,
(1,): 3.0,
(1, 1): 1.0,
(1, 1, '127.0.0.1:6010'): 1.0,
(1, 1, '127.0.0.1:6010', 0): 1.0,
(1, 2): 1.0,
(1, 2, '127.0.0.1:6020'): 1.0,
(1, 2, '127.0.0.1:6020', 1): 1.0,
(1, 3): 1.0,
(1, 3, '127.0.0.1:6030'): 1.0,
(1, 3, '127.0.0.1:6030', 2): 1.0,
(1, 4): 1.0,
(1, 4, '127.0.0.1:6040'): 1.0,
(1, 4, '127.0.0.1:6040', 3): 1.0}
"""
# Used by walk_tree to know what entries to create for each recursive
# call.