openstack/nova
Code Issues Proposed changes

Merge "Allow compute monitors in different namespaces"

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Jenkins 2015-08-31 16:41:35 +00:00 committed by Gerrit Code Review
commit 51e9b20a83
2 changed files with 79 additions and 31 deletions
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82
nova/compute/monitors/__init__.py
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@ -36,7 +36,12 @@ compute_monitors_opts = [
help='A list of monitors that can be used for getting '
'compute metrics. You can use the alias/name from '
'the setuptools entry points for nova.compute.monitors.* '
'namespaces.'),
'namespaces. If no namespace is supplied, the "cpu." '
'namespace is assumed for backwards-compatibility. '
'An example value that would enable both the CPU and '
'NUMA memory bandwidth monitors that used the virt '
'driver variant: '
'["cpu.virt_driver", "numa_mem_bw.virt_driver"]'),
]
CONF = cfg.CONF
@ -46,39 +51,68 @@ LOG = logging.getLogger(__name__)
class MonitorHandler(object):
NAMESPACES = [
'nova.compute.monitors.cpu',
]
def __init__(self, resource_tracker):
self.cpu_monitor_loaded = False
# Dictionary keyed by the monitor type namespace. Value is the
# first loaded monitor of that namespace or False.
self.type_monitor_loaded = {ns: False for ns in self.NAMESPACES}
ns = 'nova.compute.monitors.cpu'
cpu_plugin_mgr = enabled.EnabledExtensionManager(
namespace=ns,
invoke_on_load=True,
check_func=self.check_enabled_cpu_monitor,
invoke_args=(resource_tracker,)
)
self.monitors = [obj.obj for obj in cpu_plugin_mgr]
self.monitors = []
for ns in self.NAMESPACES:
plugin_mgr = enabled.EnabledExtensionManager(
namespace=ns,
invoke_on_load=True,
check_func=self.check_enabled_monitor,
invoke_args=(resource_tracker,)
)
self.monitors += [ext.obj for ext in plugin_mgr]
def check_enabled_cpu_monitor(self, ext):
if self.cpu_monitor_loaded is not False:
msg = _LW("Excluding CPU monitor %(monitor_name)s. Already "
"loaded %(loaded_cpu_monitor)s.")
def check_enabled_monitor(self, ext):
"""Ensures that only one monitor is specified of any type."""
# The extension does not have a namespace attribute, unfortunately,
# but we can get the namespace by examining the first part of the
# entry_point_target attribute, which looks like this:
# 'nova.compute.monitors.cpu.virt_driver:Monitor'
ept = ext.entry_point_target
ept_parts = ept.split(':')
namespace_parts = ept_parts[0].split('.')
namespace = '.'.join(namespace_parts[0:-1])
if self.type_monitor_loaded[namespace] is not False:
msg = _LW("Excluding %(namespace)s monitor %(monitor_name)s. "
"Already loaded %(loaded_monitor)s.")
msg = msg % {
'namespace': namespace,
'monitor_name': ext.name,
'loaded_cpu_monitor': self.cpu_monitor_loaded
'loaded_monitor': self.type_monitor_loaded[namespace]
}
LOG.warn(msg)
return False
# TODO(jaypipes): Right now, we only have CPU monitors, so we don't
# need to check if the plugin is a CPU monitor or not. Once non-CPU
# monitors are added, change this to check either the base class or
# the set of metric names returned to ensure only a single CPU
# monitor is loaded at any one time.
if ext.name in CONF.compute_monitors:
self.cpu_monitor_loaded = ext.name
# NOTE(jaypipes): We used to only have CPU monitors, so
# CONF.compute_monitors could contain "virt_driver" without any monitor
# type namespace. So, to maintain backwards-compatibility with that
# older way of specifying monitors, we first loop through any values in
# CONF.compute_monitors and put any non-namespace'd values into the
# 'cpu' namespace.
cfg_monitors = ['cpu.' + cfg if '.' not in cfg else cfg
for cfg in CONF.compute_monitors]
# NOTE(jaypipes): Append 'nova.compute.monitors.' to any monitor value
# that doesn't have it to allow CONF.compute_monitors to use shortened
# namespaces (like 'cpu.' instead of 'nova.compute.monitors.cpu.')
cfg_monitors = ['nova.compute.monitors.' + cfg
if 'nova.compute.monitors.' not in cfg else cfg
for cfg in cfg_monitors]
if namespace + '.' + ext.name in cfg_monitors:
self.type_monitor_loaded[namespace] = ext.name
return True
msg = _LW("Excluding CPU monitor %(monitor_name)s. Not in the "
"list of enabled monitors (CONF.compute_monitors).")
msg = _LW("Excluding %(namespace)s monitor %(monitor_name)s. "
"Not in the list of enabled monitors "
"(CONF.compute_monitors).")
msg = msg % {
'namespace': namespace,
'monitor_name': ext.name,
}
LOG.warn(msg)

28
nova/tests/unit/compute/monitors/test_monitors.py
View File

@ -25,15 +25,29 @@ class MonitorsTestCase(test.NoDBTestCase):
"""Test case for monitors."""
@mock.patch('stevedore.enabled.EnabledExtensionManager')
def test_check_enabled_cpu_monitor(self, _mock_ext_manager):
def test_check_enabled_monitor(self, _mock_ext_manager):
class FakeExt(object):
def __init__(self, name):
def __init__(self, ept, name):
self.entry_point_target = ept
self.name = name
# We check to ensure only one CPU monitor is loaded...
self.flags(compute_monitors=['cpu_mon1', 'cpu_mon2'])
self.flags(compute_monitors=['mon1', 'mon2'])
handler = monitors.MonitorHandler(None)
ext_cpu_mon1 = FakeExt('cpu_mon1')
ext_cpu_mon2 = FakeExt('cpu_mon2')
self.assertTrue(handler.check_enabled_cpu_monitor(ext_cpu_mon1))
self.assertFalse(handler.check_enabled_cpu_monitor(ext_cpu_mon2))
ext_cpu_mon1 = FakeExt('nova.compute.monitors.cpu.virt_driver:Monitor',
'mon1')
ext_cpu_mon2 = FakeExt('nova.compute.monitors.cpu.virt_driver:Monitor',
'mon2')
self.assertTrue(handler.check_enabled_monitor(ext_cpu_mon1))
self.assertFalse(handler.check_enabled_monitor(ext_cpu_mon2))
# We check to ensure that the auto-prefixing of the CPU
# namespace is handled properly...
self.flags(compute_monitors=['cpu.mon1', 'mon2'])
handler = monitors.MonitorHandler(None)
ext_cpu_mon1 = FakeExt('nova.compute.monitors.cpu.virt_driver:Monitor',
'mon1')
ext_cpu_mon2 = FakeExt('nova.compute.monitors.cpu.virt_driver:Monitor',
'mon2')
self.assertTrue(handler.check_enabled_monitor(ext_cpu_mon1))
self.assertFalse(handler.check_enabled_monitor(ext_cpu_mon2))