openstack/cinder
Code Issues Proposed changes

Fix capacity filter to allow oversubscription

Browse Source 
Currently the capacity filter does not allow oversubscrition
if the free physical capacity is less than the new volume size.
This was based on the assumption that a new thinly provisioned
volume will be consumed right away. This assumption does not
allow us to take full advantage of thin provisioning.

The fix is to allow oversubscription if thin provisioning is
supported and max_over_subscription_ratio is greater than or
equal to 1. The free physical capacity will not be used to
compare with the new volume size for a backend that supports
oversubscription in thin provisioning. The oversubscription
ratio and virtual free capacity will still be used to decide
whether a backend can be chosen for thin provisioning.

Closes-Bug: #1458976
Change-Id: I4c8904445654db839c25ded420915f83c3756f94
This commit is contained in:
Xing Yang
2015-05-27 12:58:04 -04:00
parent 275912c6cc
commit 75953752e4
2 changed files with 65 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
cinder/scheduler/filters/capacity_filter.py
View File

@@ -80,22 +80,13 @@ class CapacityFilter(filters.BaseHostFilter):
msg_args = {"host": host_state.host,
"requested": volume_size,
"available": free}
if free < volume_size:
LOG.warning(_LW("Insufficient free space for volume creation "
"on host %(host)s (requested / avail): "
"%(requested)s/%(available)s"), msg_args)
return free >= volume_size
else:
LOG.debug("Space information for volume creation "
"on host %(host)s (requested / avail): "
"%(requested)s/%(available)s", msg_args)
# Only evaluate using max_over_subscription_ratio if
# thin_provisioning_support is True. Check if the ratio of
# provisioned capacity over total capacity has exceeded over
# subscription ratio.
if (host_state.thin_provisioning_support and
host_state.max_over_subscription_ratio >= 1):
host_state.max_over_subscription_ratio > 1):
provisioned_ratio = ((host_state.provisioned_capacity_gb +
volume_size) / total)
if provisioned_ratio >= host_state.max_over_subscription_ratio:
@@ -113,4 +104,14 @@ class CapacityFilter(filters.BaseHostFilter):
free_virtual = free * host_state.max_over_subscription_ratio
return free_virtual >= volume_size
return free >= volume_size
if free < volume_size:
LOG.warning(_LW("Insufficient free space for volume creation "
"on host %(host)s (requested / avail): "
"%(requested)s/%(available)s"), msg_args)
return False
LOG.debug("Space information for volume creation "
"on host %(host)s (requested / avail): "
"%(requested)s/%(available)s", msg_args)
return True

62
cinder/tests/unit/scheduler/test_host_filters.py
View File

@@ -162,6 +162,28 @@ class CapacityFilterTestCase(HostFiltersTestCase):
'service': service})
self.assertTrue(filt_cls.host_passes(host, filter_properties))
@mock.patch('cinder.utils.service_is_up')
def test_filter_over_subscription_less_than_1(self, _mock_serv_is_up):
_mock_serv_is_up.return_value = True
filt_cls = self.class_map['CapacityFilter']()
filter_properties = {'size': 200,
'capabilities:thin_provisioning_support':
'<is> True',
'capabilities:thick_provisioning_support':
'<is> False'}
service = {'disabled': False}
host = fakes.FakeHostState('host1',
{'total_capacity_gb': 500,
'free_capacity_gb': 100,
'provisioned_capacity_gb': 400,
'max_over_subscription_ratio': 0.8,
'reserved_percentage': 0,
'thin_provisioning_support': True,
'thick_provisioning_support': False,
'updated_at': None,
'service': service})
self.assertFalse(filt_cls.host_passes(host, filter_properties))
@mock.patch('cinder.utils.service_is_up')
def test_filter_over_subscription_fails(self, _mock_serv_is_up):
_mock_serv_is_up.return_value = True
@@ -175,8 +197,8 @@ class CapacityFilterTestCase(HostFiltersTestCase):
host = fakes.FakeHostState('host1',
{'total_capacity_gb': 500,
'free_capacity_gb': 200,
'provisioned_capacity_gb': 500,
'max_over_subscription_ratio': 1.0,
'provisioned_capacity_gb': 700,
'max_over_subscription_ratio': 1.5,
'reserved_percentage': 5,
'thin_provisioning_support': True,
'thick_provisioning_support': False,
@@ -188,7 +210,7 @@ class CapacityFilterTestCase(HostFiltersTestCase):
def test_filter_over_subscription_fails2(self, _mock_serv_is_up):
_mock_serv_is_up.return_value = True
filt_cls = self.class_map['CapacityFilter']()
filter_properties = {'size': 30,
filter_properties = {'size': 2000,
'capabilities:thin_provisioning_support':
'<is> True',
'capabilities:thick_provisioning_support':
@@ -197,8 +219,8 @@ class CapacityFilterTestCase(HostFiltersTestCase):
host = fakes.FakeHostState('host1',
{'total_capacity_gb': 500,
'free_capacity_gb': 30,
'provisioned_capacity_gb': 500,
'max_over_subscription_ratio': 1.0,
'provisioned_capacity_gb': 9000,
'max_over_subscription_ratio': 20,
'reserved_percentage': 0,
'thin_provisioning_support': True,
'thick_provisioning_support': False,
@@ -219,7 +241,7 @@ class CapacityFilterTestCase(HostFiltersTestCase):
host = fakes.FakeHostState('host1',
{'total_capacity_gb': 500,
'free_capacity_gb': 100,
'provisioned_capacity_gb': 500,
'provisioned_capacity_gb': 1000,
'max_over_subscription_ratio': 2.0,
'reserved_percentage': 5,
'thin_provisioning_support': True,
@@ -264,8 +286,8 @@ class CapacityFilterTestCase(HostFiltersTestCase):
service = {'disabled': False}
host = fakes.FakeHostState('host1',
{'total_capacity_gb': 500,
'free_capacity_gb': 100,
'provisioned_capacity_gb': 400,
'free_capacity_gb': 0,
'provisioned_capacity_gb': 800,
'max_over_subscription_ratio': 2.0,
'reserved_percentage': 5,
'thin_provisioning_support': True,
@@ -296,6 +318,28 @@ class CapacityFilterTestCase(HostFiltersTestCase):
'service': service})
self.assertTrue(filt_cls.host_passes(host, filter_properties))
@mock.patch('cinder.utils.service_is_up')
def test_filter_reserved_thin_true_passes(self, _mock_serv_is_up):
_mock_serv_is_up.return_value = True
filt_cls = self.class_map['CapacityFilter']()
filter_properties = {'size': 100,
'capabilities:thin_provisioning_support':
'<is> True',
'capabilities:thick_provisioning_support':
'<is> False'}
service = {'disabled': False}
host = fakes.FakeHostState('host1',
{'total_capacity_gb': 500,
'free_capacity_gb': 80,
'provisioned_capacity_gb': 600,
'max_over_subscription_ratio': 2.0,
'reserved_percentage': 5,
'thin_provisioning_support': True,
'thick_provisioning_support': False,
'updated_at': None,
'service': service})
self.assertTrue(filt_cls.host_passes(host, filter_properties))
@mock.patch('cinder.utils.service_is_up')
def test_filter_reserved_thin_thick_true_fails2(self, _mock_serv_is_up):
_mock_serv_is_up.return_value = True
@@ -309,7 +353,7 @@ class CapacityFilterTestCase(HostFiltersTestCase):
host = fakes.FakeHostState('host1',
{'total_capacity_gb': 500,
'free_capacity_gb': 99,
'provisioned_capacity_gb': 400,
'provisioned_capacity_gb': 1000,
'max_over_subscription_ratio': 2.0,
'reserved_percentage': 5,
'thin_provisioning_support': True,