openstack/nova
Code Issues Proposed changes

Merge "Don't persist zero allocation ratios in ResourceTracker"

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Zuul 2018-09-05 11:50:11 +00:00 committed by Gerrit Code Review
commit 685d601cb2
2 changed files with 60 additions and 4 deletions
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29
nova/compute/resource_tracker.py
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@ -617,10 +617,31 @@ class ResourceTracker(object):
stats.digest_stats(resources.get('stats'))
compute_node.stats = stats
# update the allocation ratios for the related ComputeNode object
compute_node.ram_allocation_ratio = self.ram_allocation_ratio
compute_node.cpu_allocation_ratio = self.cpu_allocation_ratio
compute_node.disk_allocation_ratio = self.disk_allocation_ratio
# Update the allocation ratios for the related ComputeNode object
# but only if the configured values are not the default 0.0; the
# ComputeNode._from_db_object method takes care of providing default
# allocation ratios when the config is left at the 0.0 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
# 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
# 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).
# 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
# 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:
setattr(compute_node, attr, conf_alloc_ratio)
# now copy rest to compute_node
compute_node.update_from_virt_driver(resources)

35
nova/tests/unit/compute/test_resource_tracker.py
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@ -1506,6 +1506,41 @@ class TestUpdateComputeNode(BaseTestCase):
self.assertRaises(exc.ComputeHostNotFound,
self.rt.get_node_uuid, 'foo')
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.
"""
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 explicit ratio config values to 1.0 (the default is 0.0).
for res in ('cpu', 'disk', 'ram'):
opt_name = '%s_allocation_ratio' % res
CONF.set_override(opt_name, 1.0)
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 changed.
changes = compute.obj_get_changes()
for res in ('cpu', 'disk', 'ram'):
attr_name = '%s_allocation_ratio' % res
self.assertIn(attr_name, changes)
self.assertEqual(1.0, changes[attr_name])
class TestNormalizatInventoryFromComputeNode(test.NoDBTestCase):
def test_normalize_libvirt(self):