openstack
/
nova
Code Issues Proposed changes

Change the default values of XXX_allocation_ratio 

This patch including 2 changes:
1. Change the default values for
CONF.(cpu|ram|disk)_allocation_ratio to ``None``

2. Change the resource tracker to overwrite the compute node's
allocations ratios to the value of the XXX_allocation_ratio if
the value of these options is NOT ``None`` or ``0.0``.

The "0.0" condition is for upgrade impact, and it will be
removed in the next version (T version).

Change-Id: I6893d63dc5f29bc2eb348fe0aa9fbc8490e6eb40
blueprint: initial-allocation-ratios
This commit is contained in:
Yikun Jiang 2018-09-15 11:14:51 +08:00
parent 5d536b0d3a
commit 212eff600a
6 changed files with 88 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
nova/compute/resource_tracker.py
View File

@ -621,29 +621,33 @@ class ResourceTracker(object):
compute_node.stats = stats
# Update the allocation ratios for the related ComputeNode object
# but only if the configured values are not the default 0.0; the
# but only if the configured values are not the default; the
# ComputeNode._from_db_object method takes care of providing default
# allocation ratios when the config is left at the 0.0 default, so
# allocation ratios when the config is left at the default, so
# we'll really end up with something like a
# ComputeNode.cpu_allocation_ratio of 16.0, not 0.0. We want to avoid
# resetting the ComputeNode fields to 0.0 because that will make
# ComputeNode.cpu_allocation_ratio of 16.0. We want to avoid
# resetting the ComputeNode fields to None because that will make
# the _resource_change method think something changed when really it
# didn't.
# TODO(mriedem): Will this break any scenarios where an operator is
# trying to *reset* the allocation ratios by changing config from
# non-0.0 back to 0.0? Maybe we should only do this if the fields on
# non-None back to None? Maybe we should only do this if the fields on
# the ComputeNode object are not already set. For example, let's say
# the cpu_allocation_ratio config was 1.0 and then the operator wants
# to get back to the default (16.0 via the facade), and to do that they
# change the config back to 0.0 (or just unset the config option).
# change the config back to None (or just unset the config option).
# Should we support that or treat these config options as "sticky" in
# that once you start setting them, you can't go back to the implied
# defaults by unsetting or resetting to 0.0? Sort of like how
# defaults by unsetting or resetting to None? Sort of like how
# per-tenant quota is sticky once you change it in the API.
for res in ('cpu', 'disk', 'ram'):
attr = '%s_allocation_ratio' % res
conf_alloc_ratio = getattr(self, attr)
if conf_alloc_ratio != 0.0:
# NOTE(yikun): In Stein version, we change the default value of
# (cpu|ram|disk)_allocation_ratio from 0.0 to None, but we still
# should allow 0.0 to keep compatibility, and this 0.0 condition
# will be removed in the next version (T version).
if conf_alloc_ratio not in (0.0, None):
setattr(compute_node, attr, conf_alloc_ratio)
# now copy rest to compute_node

36
nova/conf/compute.py
View File

@ -381,7 +381,7 @@ Possible values:
allocation_ratio_opts = [
cfg.FloatOpt('cpu_allocation_ratio',
default=0.0,
default=None,
min=0.0,
help="""
This option helps you specify virtual CPU to physical CPU allocation ratio.
@ -395,18 +395,18 @@ This configuration specifies ratio for CoreFilter which can be set
per compute node. For AggregateCoreFilter, it will fall back to this
configuration value if no per-aggregate setting is found.
NOTE: This can be set per-compute, or if set to 0.0, the value
set on the scheduler node(s) or compute node(s) will be used
and defaulted to 16.0. Once set to a non-default value, it is not possible
to "unset" the config to get back to the default behavior. If you want
to reset back to the default, explicitly specify 16.0.
NOTE: If this option is set to something *other than* ``None`` or ``0.0``, the
allocation ratio will be overwritten by the value of this option, otherwise,
the allocation ratio will not change. Once set to a non-default value, it is
not possible to "unset" the config to get back to the default behavior. If you
want to reset back to the default, explicitly specify 16.0.
Possible values:
* Any valid positive integer or float value
"""),
cfg.FloatOpt('ram_allocation_ratio',
default=0.0,
default=None,
min=0.0,
help="""
This option helps you specify virtual RAM to physical RAM
@ -421,18 +421,18 @@ This configuration specifies ratio for RamFilter which can be set
per compute node. For AggregateRamFilter, it will fall back to this
configuration value if no per-aggregate setting found.
NOTE: This can be set per-compute, or if set to 0.0, the value
set on the scheduler node(s) or compute node(s) will be used and
defaulted to 1.5. Once set to a non-default value, it is not possible
to "unset" the config to get back to the default behavior. If you want
to reset back to the default, explicitly specify 1.5.
NOTE: If this option is set to something *other than* ``None`` or ``0.0``, the
allocation ratio will be overwritten by the value of this option, otherwise,
the allocation ratio will not change. Once set to a non-default value, it is
not possible to "unset" the config to get back to the default behavior. If you
want to reset back to the default, explicitly specify 1.5.
Possible values:
* Any valid positive integer or float value
"""),
cfg.FloatOpt('disk_allocation_ratio',
default=0.0,
default=None,
min=0.0,
help="""
This option helps you specify virtual disk to physical disk
@ -451,11 +451,11 @@ images. It can be set to a value between 0.0 and 1.0 in order
to preserve a percentage of the disk for uses other than
instances.
NOTE: This can be set per-compute, or if set to 0.0, the value
set on the scheduler node(s) or compute node(s) will be used and
defaulted to 1.0. Once set to a non-default value, it is not possible
to "unset" the config to get back to the default behavior. If you want
to reset back to the default, explicitly specify 1.0.
NOTE: If this option is set to something *other than* ``None`` or ``0.0``, the
allocation ratio will be overwritten by the value of this option, otherwise,
the allocation ratio will not change. Once set to a non-default value, it is
not possible to "unset" the config to get back to the default behavior. If you
want to reset back to the default, explicitly specify 1.0.
Possible values:

9
nova/objects/compute_node.py
View File

@ -197,13 +197,16 @@ class ComputeNode(base.NovaPersistentObject, base.NovaObject):
# or the compute node is updated but the default value has
# not been changed
value = getattr(CONF, key)
if value == 0.0 and key == 'cpu_allocation_ratio':
if value in (0.0, None) \
and key == 'cpu_allocation_ratio':
# It's not specified either on the controller
value = 16.0
if value == 0.0 and key == 'ram_allocation_ratio':
if value in (0.0, None) \
and key == 'ram_allocation_ratio':
# It's not specified either on the controller
value = 1.5
if value == 0.0 and key == 'disk_allocation_ratio':
if value in (0.0, None) \
and key == 'disk_allocation_ratio':
# It's not specified either on the controller
value = 1.0
elif key == 'mapped':

29
nova/tests/unit/compute/test_resource_tracker.py
View File

@ -1550,7 +1550,7 @@ class TestUpdateComputeNode(BaseTestCase):
def test_copy_resources_no_update_allocation_ratios(self):
"""Tests that a ComputeNode object's allocation ratio fields are
not set if the configured allocation ratio values are default 0.0.
not set if the configured allocation ratio values are default None.
"""
self._setup_rt()
compute = _COMPUTE_NODE_FIXTURES[0].obj_clone()
@ -1563,11 +1563,34 @@ class TestUpdateComputeNode(BaseTestCase):
attr_name = '%s_allocation_ratio' % res
self.assertNotIn(attr_name, changes)
def test_copy_resources_update_allocation_zero_ratios(self):
"""Tests that a ComputeNode object's allocation ratio fields are
not set if the configured allocation ratio values are 0.0.
"""
# NOTE(yikun): In Stein version, we change the default value of
# (cpu|ram|disk)_allocation_ratio from 0.0 to None, but we still
# should allow 0.0 to keep compatibility, and this 0.0 condition
# will be removed in the next version (T version).
# Set explicit ratio config values to 0.0 (the default is None).
for res in ('cpu', 'disk', 'ram'):
opt_name = '%s_allocation_ratio' % res
CONF.set_override(opt_name, 0.0)
self._setup_rt()
compute = _COMPUTE_NODE_FIXTURES[0].obj_clone()
compute.obj_reset_changes() # make sure we start clean
self.rt._copy_resources(
compute, self.driver_mock.get_available_resource.return_value)
# Assert that the ComputeNode fields were not changed.
changes = compute.obj_get_changes()
for res in ('cpu', 'disk', 'ram'):
attr_name = '%s_allocation_ratio' % res
self.assertNotIn(attr_name, changes)
def test_copy_resources_update_allocation_ratios_from_config(self):
"""Tests that a ComputeNode object's allocation ratio fields are
set if the configured allocation ratio values are not 0.0.
set if the configured allocation ratio values are not default.
"""
# Set explicit ratio config values to 1.0 (the default is 0.0).
# Set explicit ratio config values to 1.0 (the default is None).
for res in ('cpu', 'disk', 'ram'):
opt_name = '%s_allocation_ratio' % res
CONF.set_override(opt_name, 1.0)

25
nova/tests/unit/objects/test_compute_node.py
View File

@ -565,9 +565,25 @@ class _TestComputeNodeObject(object):
self.assertEqual(3.0, compute.ram_allocation_ratio)
self.assertEqual(0.9, compute.disk_allocation_ratio)
def test_compat_allocation_ratios_default_values(self):
def test_compat_allocation_ratios_zero_conf(self):
self.flags(cpu_allocation_ratio=0.0, ram_allocation_ratio=0.0,
disk_allocation_ratio=0.0)
compute_dict = fake_compute_node.copy()
# new computes provide allocation ratios defaulted to 0.0
# the computes provide allocation ratios None
compute_dict['cpu_allocation_ratio'] = None
compute_dict['ram_allocation_ratio'] = None
compute_dict['disk_allocation_ratio'] = None
cls = objects.ComputeNode
compute = cls._from_db_object(self.context, cls(), compute_dict)
self.assertEqual(16.0, compute.cpu_allocation_ratio)
self.assertEqual(1.5, compute.ram_allocation_ratio)
self.assertEqual(1.0, compute.disk_allocation_ratio)
def test_compat_allocation_ratios_None_conf_zero_values(self):
# the CONF.x_allocation_ratio is None by default
compute_dict = fake_compute_node.copy()
# the computes provide allocation ratios 0.0
compute_dict['cpu_allocation_ratio'] = 0.0
compute_dict['ram_allocation_ratio'] = 0.0
compute_dict['disk_allocation_ratio'] = 0.0
@ -578,9 +594,10 @@ class _TestComputeNodeObject(object):
self.assertEqual(1.5, compute.ram_allocation_ratio)
self.assertEqual(1.0, compute.disk_allocation_ratio)
def test_compat_allocation_ratios_old_compute_default_values(self):
def test_compat_allocation_ratios_None_conf_None_values(self):
# the CONF.x_allocation_ratio is None by default
compute_dict = fake_compute_node.copy()
# old computes don't provide allocation ratios to the table
# # the computes provide allocation ratios None
compute_dict['cpu_allocation_ratio'] = None
compute_dict['ram_allocation_ratio'] = None
compute_dict['disk_allocation_ratio'] = None

5
releasenotes/notes/add_initial_allocation_ratio-2d2666d62426a4bf.yaml Normal file
View File

@ -0,0 +1,5 @@
---
upgrade:
- |
The default value for the "cpu_allocation_ratio", "ram_allocation_ratio"
and "disk_allocation_ratio" configurations have been changed to ``None``.