x/python-ganttclient
Code Issues Proposed changes

Collect more accurate bandwidth data for XenServer

Browse Source 
This changes the method used to poll xenserver for bandwidth data.
The reccomended way of collecting such data from xenserver (namely the
RRD files provided by the hosts) do not seem to be reliable, they
will sometimes be correct, often will be signifigantly under (> 10%),
and occasionally will show artifacts, such as phantom 4gb bandwidth
'spikes'.

This patch changes that to use the much simpler method of simply polling the
byte counters on the VIF network devices on the host. (We have old non-nova
code that does that on xenserver, and that method is known to work).

This should also make it much easier for other hypervisors other than
xenserver to implement bandwidth polling, as polling the counters is a rather
more universal method.

Fixes bug 1055737

Change-Id: I6a280d8bbfcc74914f888b11bc09349a270a5f58
This commit is contained in:
Monsyne Dragon
2012-09-24 19:38:09 +00:00
parent 4c37df6c4e
commit e6de054235
2 changed files with 89 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
nova/tests/test_db_api.py
View File

@@ -478,18 +478,24 @@ class DbApiTestCase(test.TestCase):
'start_period': start_period,
'bw_in': 100,
'bw_out': 200,
'last_ctr_in': 12345,
'last_ctr_out': 67890,
'last_refreshed': now},
{'uuid': 'fake_uuid2',
'mac': 'fake_mac2',
'start_period': start_period,
'bw_in': 200,
'bw_out': 300,
'last_ctr_in': 22345,
'last_ctr_out': 77890,
'last_refreshed': now},
{'uuid': 'fake_uuid3',
'mac': 'fake_mac3',
'start_period': start_period,
'bw_in': 400,
'bw_out': 500,
'last_ctr_in': 32345,
'last_ctr_out': 87890,
'last_refreshed': uuid3_refreshed}]
def _compare(bw_usage, expected):
@@ -504,18 +510,19 @@ class DbApiTestCase(test.TestCase):
# Add 3 entries
db.bw_usage_update(ctxt, 'fake_uuid1',
'fake_mac1', start_period,
100, 200)
100, 200, 12345, 67890)
db.bw_usage_update(ctxt, 'fake_uuid2',
'fake_mac2', start_period,
100, 200)
100, 200, 42, 42)
# Test explicit refreshed time
db.bw_usage_update(ctxt, 'fake_uuid3',
'fake_mac3', start_period,
400, 500, last_refreshed=uuid3_refreshed)
400, 500, 32345, 87890,
last_refreshed=uuid3_refreshed)
# Update 2nd entry
db.bw_usage_update(ctxt, 'fake_uuid2',
'fake_mac2', start_period,
200, 300)
200, 300, 22345, 77890)
bw_usages = db.bw_usage_get_by_uuids(ctxt,
['fake_uuid1', 'fake_uuid2', 'fake_uuid3'], start_period)

90
nova/tests/test_xenapi.py
View File

@@ -1442,11 +1442,23 @@ class XenAPIGenerateLocal(stubs.XenAPITestBase):
self.assertCalled(instance)
class XenAPIBWUsageTestCase(stubs.XenAPITestBase):
class XenAPIBWCountersTestCase(stubs.XenAPITestBase):
FAKE_VMS = {'test1:ref': dict(name_label='test1',
other_config=dict(nova_uuid='hash'),
domid='12',
_vifmap={'0': "a:b:c:d...",
'1': "e:f:12:q..."}),
'test2:ref': dict(name_label='test2',
other_config=dict(nova_uuid='hash'),
domid='42',
_vifmap={'0': "a:3:c:d...",
'1': "e:f:42:q..."}),
}
def setUp(self):
super(XenAPIBWUsageTestCase, self).setUp()
self.stubs.Set(vm_utils, 'compile_metrics',
XenAPIBWUsageTestCase._fake_compile_metrics)
super(XenAPIBWCountersTestCase, self).setUp()
self.stubs.Set(vm_utils, 'list_vms',
XenAPIBWCountersTestCase._fake_list_vms)
self.flags(xenapi_connection_url='test_url',
xenapi_connection_password='test_pass',
firewall_driver='nova.virt.xenapi.firewall.'
@@ -1454,21 +1466,75 @@ class XenAPIBWUsageTestCase(stubs.XenAPITestBase):
stubs.stubout_session(self.stubs, stubs.FakeSessionForVMTests)
self.conn = xenapi_conn.XenAPIDriver(False)
@classmethod
def _fake_compile_metrics(cls, start_time, stop_time=None):
raise exception.CouldNotFetchMetrics()
def _fake_get_vif_device_map(vm_rec):
return vm_rec['_vifmap']
def test_get_all_bw_usage_in_failure_case(self):
"""Test that get_all_bw_usage returns an empty list when metrics
compilation failed. c.f. bug #910045.
self.stubs.Set(self.conn._vmops, "_get_vif_device_map",
_fake_get_vif_device_map)
@classmethod
def _fake_list_vms(cls, session):
return cls.FAKE_VMS.iteritems()
@classmethod
def _fake_fetch_bandwidth_mt(cls, session):
return {}
@classmethod
def _fake_fetch_bandwidth(cls, session):
return {'42':
{'0': {'bw_in': 21024, 'bw_out': 22048},
'1': {'bw_in': 231337, 'bw_out': 221212121}},
'12':
{'0': {'bw_in': 1024, 'bw_out': 2048},
'1': {'bw_in': 31337, 'bw_out': 21212121}},
}
def test_get_all_bw_counters(self):
class testinstance(object):
def __init__(self, name, uuid):
self.name = name
self.uuid = uuid
self.stubs.Set(vm_utils, 'fetch_bandwidth',
XenAPIBWCountersTestCase._fake_fetch_bandwidth)
result = self.conn.get_all_bw_counters([testinstance(
name='test1',
uuid='1-2-3'),
testinstance(
name='test2',
uuid='4-5-6')])
self.assertEqual(len(result), 4)
self.assertIn(dict(uuid='1-2-3',
mac_address="a:b:c:d...",
bw_in=1024,
bw_out=2048), result)
self.assertIn(dict(uuid='1-2-3',
mac_address="e:f:12:q...",
bw_in=31337,
bw_out=21212121), result)
self.assertIn(dict(uuid='4-5-6',
mac_address="a:3:c:d...",
bw_in=21024,
bw_out=22048), result)
self.assertIn(dict(uuid='4-5-6',
mac_address="e:f:42:q...",
bw_in=231337,
bw_out=221212121), result)
def test_get_all_bw_counters_in_failure_case(self):
"""Test that get_all_bw_conters returns an empty list when
no data returned from Xenserver. c.f. bug #910045.
"""
class testinstance(object):
def __init__(self):
self.name = "instance-0001"
self.uuid = "1-2-3-4-5"
result = self.conn.get_all_bw_usage([testinstance()],
timeutils.utcnow())
self.stubs.Set(vm_utils, 'fetch_bandwidth',
XenAPIBWCountersTestCase._fake_fetch_bandwidth_mt)
result = self.conn.get_all_bw_counters([testinstance()])
self.assertEqual(result, [])