openstack/charm-ceph-osd
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Pre-release charm-helpers sync

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To begin release testing get each charm up to date with lp:charm-helpers

Change-Id: I671fa63c665337295c1c448709fcc38123d4508d
This commit is contained in:
David Ames
2016-07-15 10:48:32 -07:00
parent 79c6c28649
commit ab5de8087a
6 changed files with 174 additions and 58 deletions
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168
hooks/charmhelpers/contrib/storage/linux/ceph.py
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@@ -21,9 +21,10 @@
# James Page <james.page@ubuntu.com>
# Adam Gandelman <adamg@ubuntu.com>
#
import bisect
import errno
import hashlib
import math
import six
import os
@@ -76,8 +77,16 @@ log to syslog = {use_syslog}
err to syslog = {use_syslog}
clog to syslog = {use_syslog}
"""
# For 50 < osds < 240,000 OSDs (Roughly 1 Exabyte at 6T OSDs)
powers_of_two = [8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608]
# The number of placement groups per OSD to target for placement group
# calculations. This number is chosen as 100 due to the ceph PG Calc
# documentation recommending to choose 100 for clusters which are not
# expected to increase in the foreseeable future. Since the majority of the
# calculations are done on deployment, target the case of non-expanding
# clusters as the default.
DEFAULT_PGS_PER_OSD_TARGET = 100
DEFAULT_POOL_WEIGHT = 10.0
LEGACY_PG_COUNT = 200
def validator(value, valid_type, valid_range=None):
@@ -184,42 +193,106 @@ class Pool(object):
check_call(['ceph', '--id', self.service, 'osd', 'tier', 'remove-overlay', self.name])
check_call(['ceph', '--id', self.service, 'osd', 'tier', 'remove', self.name, cache_pool])
def get_pgs(self, pool_size):
"""
:param pool_size: int. pool_size is either the number of replicas for replicated pools or the K+M sum for
erasure coded pools
def get_pgs(self, pool_size, percent_data=DEFAULT_POOL_WEIGHT):
"""Return the number of placement groups to use when creating the pool.
Returns the number of placement groups which should be specified when
creating the pool. This is based upon the calculation guidelines
provided by the Ceph Placement Group Calculator (located online at
http://ceph.com/pgcalc/).
The number of placement groups are calculated using the following:
(Target PGs per OSD) * (OSD #) * (%Data)
----------------------------------------
(Pool size)
Per the upstream guidelines, the OSD # should really be considered
based on the number of OSDs which are eligible to be selected by the
pool. Since the pool creation doesn't specify any of CRUSH set rules,
the default rule will be dependent upon the type of pool being
created (replicated or erasure).
This code makes no attempt to determine the number of OSDs which can be
selected for the specific rule, rather it is left to the user to tune
in the form of 'expected-osd-count' config option.
:param pool_size: int. pool_size is either the number of replicas for
replicated pools or the K+M sum for erasure coded pools
:param percent_data: float. the percentage of data that is expected to
be contained in the pool for the specific OSD set. Default value
is to assume 10% of the data is for this pool, which is a
relatively low % of the data but allows for the pg_num to be
increased. NOTE: the default is primarily to handle the scenario
where related charms requiring pools has not been upgraded to
include an update to indicate their relative usage of the pools.
:return: int. The number of pgs to use.
"""
# Note: This calculation follows the approach that is provided
# by the Ceph PG Calculator located at http://ceph.com/pgcalc/.
validator(value=pool_size, valid_type=int)
# Ensure that percent data is set to something - even with a default
# it can be set to None, which would wreak havoc below.
if percent_data is None:
percent_data = DEFAULT_POOL_WEIGHT
# If the expected-osd-count is specified, then use the max between
# the expected-osd-count and the actual osd_count
osd_list = get_osds(self.service)
if not osd_list:
expected = config('expected-osd-count') or 0
if osd_list:
osd_count = max(expected, len(osd_list))
# Log a message to provide some insight if the calculations claim
# to be off because someone is setting the expected count and
# there are more OSDs in reality. Try to make a proper guess
# based upon the cluster itself.
if expected and osd_count != expected:
log("Found more OSDs than provided expected count. "
"Using the actual count instead", INFO)
elif expected:
# Use the expected-osd-count in older ceph versions to allow for
# a more accurate pg calculations
osd_count = expected
else:
# NOTE(james-page): Default to 200 for older ceph versions
# which don't support OSD query from cli
return 200
return LEGACY_PG_COUNT
osd_list_length = len(osd_list)
# Calculate based on Ceph best practices
if osd_list_length < 5:
return 128
elif 5 < osd_list_length < 10:
return 512
elif 10 < osd_list_length < 50:
return 4096
percent_data /= 100.0
target_pgs_per_osd = config('pgs-per-osd') or DEFAULT_PGS_PER_OSD_TARGET
num_pg = (target_pgs_per_osd * osd_count * percent_data) // pool_size
# The CRUSH algorithm has a slight optimization for placement groups
# with powers of 2 so find the nearest power of 2. If the nearest
# power of 2 is more than 25% below the original value, the next
# highest value is used. To do this, find the nearest power of 2 such
# that 2^n <= num_pg, check to see if its within the 25% tolerance.
exponent = math.floor(math.log(num_pg, 2))
nearest = 2 ** exponent
if (num_pg - nearest) > (num_pg * 0.25):
# Choose the next highest power of 2 since the nearest is more
# than 25% below the original value.
return int(nearest * 2)
else:
estimate = (osd_list_length * 100) / pool_size
# Return the next nearest power of 2
index = bisect.bisect_right(powers_of_two, estimate)
return powers_of_two[index]
return int(nearest)
class ReplicatedPool(Pool):
def __init__(self, service, name, pg_num=None, replicas=2):
def __init__(self, service, name, pg_num=None, replicas=2,
percent_data=10.0):
super(ReplicatedPool, self).__init__(service=service, name=name)
self.replicas = replicas
if pg_num is None:
self.pg_num = self.get_pgs(self.replicas)
if pg_num:
# Since the number of placement groups were specified, ensure
# that there aren't too many created.
max_pgs = self.get_pgs(self.replicas, 100.0)
self.pg_num = min(pg_num, max_pgs)
else:
self.pg_num = pg_num
self.pg_num = self.get_pgs(self.replicas, percent_data)
def create(self):
if not pool_exists(self.service, self.name):
@@ -238,30 +311,39 @@ class ReplicatedPool(Pool):
# Default jerasure erasure coded pool
class ErasurePool(Pool):
def __init__(self, service, name, erasure_code_profile="default"):
def __init__(self, service, name, erasure_code_profile="default",
percent_data=10.0):
super(ErasurePool, self).__init__(service=service, name=name)
self.erasure_code_profile = erasure_code_profile
self.percent_data = percent_data
def create(self):
if not pool_exists(self.service, self.name):
# Try to find the erasure profile information so we can properly size the pgs
erasure_profile = get_erasure_profile(service=self.service, name=self.erasure_code_profile)
# Try to find the erasure profile information in order to properly
# size the number of placement groups. The size of an erasure
# coded placement group is calculated as k+m.
erasure_profile = get_erasure_profile(self.service,
self.erasure_code_profile)
# Check for errors
if erasure_profile is None:
log(message='Failed to discover erasure_profile named={}'.format(self.erasure_code_profile),
level=ERROR)
raise PoolCreationError(message='unable to find erasure profile {}'.format(self.erasure_code_profile))
msg = ("Failed to discover erasure profile named "
"{}".format(self.erasure_code_profile))
log(msg, level=ERROR)
raise PoolCreationError(msg)
if 'k' not in erasure_profile or 'm' not in erasure_profile:
# Error
log(message='Unable to find k (data chunks) or m (coding chunks) in {}'.format(erasure_profile),
level=ERROR)
raise PoolCreationError(
message='unable to find k (data chunks) or m (coding chunks) in {}'.format(erasure_profile))
msg = ("Unable to find k (data chunks) or m (coding chunks) "
"in erasure profile {}".format(erasure_profile))
log(msg, level=ERROR)
raise PoolCreationError(msg)
pgs = self.get_pgs(int(erasure_profile['k']) + int(erasure_profile['m']))
k = int(erasure_profile['k'])
m = int(erasure_profile['m'])
pgs = self.get_pgs(k + m, self.percent_data)
# Create it
cmd = ['ceph', '--id', self.service, 'osd', 'pool', 'create', self.name, str(pgs), str(pgs),
cmd = ['ceph', '--id', self.service, 'osd', 'pool', 'create',
self.name, str(pgs), str(pgs),
'erasure', self.erasure_code_profile]
try:
check_call(cmd)
@@ -955,16 +1037,22 @@ class CephBrokerRq(object):
self.request_id = str(uuid.uuid1())
self.ops = []
def add_op_create_pool(self, name, replica_count=3, pg_num=None):
def add_op_create_pool(self, name, replica_count=3, pg_num=None,
weight=None):
"""Adds an operation to create a pool.
@param pg_num setting: optional setting. If not provided, this value
will be calculated by the broker based on how many OSDs are in the
cluster at the time of creation. Note that, if provided, this value
will be capped at the current available maximum.
@param weight: the percentage of data the pool makes up
"""
if pg_num and weight:
raise ValueError('pg_num and weight are mutually exclusive')
self.ops.append({'op': 'create-pool', 'name': name,
'replicas': replica_count, 'pg_num': pg_num})
'replicas': replica_count, 'pg_num': pg_num,
'weight': weight})
def set_ops(self, ops):
"""Set request ops to provided value.
@@ -982,7 +1070,7 @@ class CephBrokerRq(object):
def _ops_equal(self, other):
if len(self.ops) == len(other.ops):
for req_no in range(0, len(self.ops)):
for key in ['replicas', 'name', 'op', 'pg_num']:
for key in ['replicas', 'name', 'op', 'pg_num', 'weight']:
if self.ops[req_no].get(key) != other.ops[req_no].get(key):
return False
else: