1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
|
# Copyright (c) 2012 Citrix Systems, Inc.
# Copyright 2010 OpenStack Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""
Management class for host-related functions (start, reboot, etc).
"""
from nova.compute import task_states
from nova.compute import vm_states
from nova import conductor
from nova import context
from nova import exception
from nova.objects import aggregate as aggregate_obj
from nova.objects import instance as instance_obj
from nova.openstack.common.gettextutils import _
from nova.openstack.common import jsonutils
from nova.openstack.common import log as logging
from nova.virt.xenapi import pool_states
from nova.virt.xenapi import vm_utils
LOG = logging.getLogger(__name__)
class Host(object):
"""
Implements host related operations.
"""
def __init__(self, session, virtapi):
self._session = session
self._virtapi = virtapi
self._conductor_api = conductor.API()
def host_power_action(self, _host, action):
"""Reboots or shuts down the host."""
args = {"action": jsonutils.dumps(action)}
methods = {"reboot": "host_reboot", "shutdown": "host_shutdown"}
response = call_xenhost(self._session, methods[action], args)
return response.get("power_action", response)
def host_maintenance_mode(self, host, mode):
"""Start/Stop host maintenance window. On start, it triggers
guest VMs evacuation.
"""
if not mode:
return 'off_maintenance'
host_list = [host_ref for host_ref in
self._session.call_xenapi('host.get_all')
if host_ref != self._session.host_ref]
migrations_counter = vm_counter = 0
ctxt = context.get_admin_context()
for vm_ref, vm_rec in vm_utils.list_vms(self._session):
for host_ref in host_list:
try:
# Ensure only guest instances are migrated
uuid = vm_rec['other_config'].get('nova_uuid')
if not uuid:
name = vm_rec['name_label']
uuid = _uuid_find(ctxt, host, name)
if not uuid:
LOG.info(_('Instance %(name)s running on %(host)s'
' could not be found in the database:'
' assuming it is a worker VM and skip'
' ping migration to a new host'),
{'name': name, 'host': host})
continue
instance = instance_obj.Instance.get_by_uuid(ctxt, uuid)
vm_counter = vm_counter + 1
aggregate = aggregate_obj.AggregateList.get_by_host(
ctxt, host, key=pool_states.POOL_FLAG)
if not aggregate:
msg = _('Aggregate for host %(host)s count not be'
' found.') % dict(host=host)
raise exception.NotFound(msg)
dest = _host_find(ctxt, self._session, aggregate[0],
host_ref)
instance.host = dest
instance.task_state = task_states.MIGRATING
instance.save()
self._session.call_xenapi('VM.pool_migrate',
vm_ref, host_ref,
{"live": "true"})
migrations_counter = migrations_counter + 1
instance.vm_state = vm_states.ACTIVE
instance.save()
break
except self._session.XenAPI.Failure:
LOG.exception(_('Unable to migrate VM %(vm_ref)s '
'from %(host)s'),
{'vm_ref': vm_ref, 'host': host})
instance.host = host
instance.vm_state = vm_states.ACTIVE
instance.save()
if vm_counter == migrations_counter:
return 'on_maintenance'
else:
raise exception.NoValidHost(reason='Unable to find suitable '
'host for VMs evacuation')
def set_host_enabled(self, host, enabled):
"""Sets the specified host's ability to accept new instances."""
# Since capabilities are gone, use service table to disable a node
# in scheduler
status = {'disabled': not enabled,
'disabled_reason': 'set by xenapi host_state'
}
cntxt = context.get_admin_context()
service = self._conductor_api.service_get_by_args(
cntxt,
host,
'nova-compute')
self._conductor_api.service_update(
cntxt,
service,
status)
args = {"enabled": jsonutils.dumps(enabled)}
response = call_xenhost(self._session, "set_host_enabled", args)
return response.get("status", response)
def get_host_uptime(self, _host):
"""Returns the result of calling "uptime" on the target host."""
response = call_xenhost(self._session, "host_uptime", {})
return response.get("uptime", response)
class HostState(object):
"""Manages information about the XenServer host this compute
node is running on.
"""
def __init__(self, session):
super(HostState, self).__init__()
self._session = session
self._stats = {}
self.update_status()
def get_host_stats(self, refresh=False):
"""Return the current state of the host. If 'refresh' is
True, run the update first.
"""
if refresh or not self._stats:
self.update_status()
return self._stats
def update_status(self):
"""Since under Xenserver, a compute node runs on a given host,
we can get host status information using xenapi.
"""
LOG.debug(_("Updating host stats"))
data = call_xenhost(self._session, "host_data", {})
if data:
sr_ref = vm_utils.scan_default_sr(self._session)
sr_rec = self._session.call_xenapi("SR.get_record", sr_ref)
total = int(sr_rec["physical_size"])
used = int(sr_rec["physical_utilisation"])
data["disk_total"] = total
data["disk_used"] = used
data["disk_available"] = total - used
data["supported_instances"] = to_supported_instances(
data.get("host_capabilities")
)
host_memory = data.get('host_memory', None)
if host_memory:
data["host_memory_total"] = host_memory.get('total', 0)
data["host_memory_overhead"] = host_memory.get('overhead', 0)
data["host_memory_free"] = host_memory.get('free', 0)
data["host_memory_free_computed"] = host_memory.get(
'free-computed', 0)
del data['host_memory']
if (data['host_hostname'] !=
self._stats.get('host_hostname', data['host_hostname'])):
LOG.error(_('Hostname has changed from %(old)s '
'to %(new)s. A restart is required to take effect.'
) % {'old': self._stats['host_hostname'],
'new': data['host_hostname']})
data['host_hostname'] = self._stats['host_hostname']
data['hypervisor_hostname'] = data['host_hostname']
self._stats = data
def to_supported_instances(host_capabilities):
if not host_capabilities:
return []
result = []
for capability in host_capabilities:
try:
ostype, _version, arch = capability.split("-")
result.append((arch, 'xapi', ostype))
except ValueError:
LOG.warning(
_("Failed to extract instance support from %s"), capability)
return result
def call_xenhost(session, method, arg_dict):
"""There will be several methods that will need this general
handling for interacting with the xenhost plugin, so this abstracts
out that behavior.
"""
# Create a task ID as something that won't match any instance ID
try:
result = session.call_plugin('xenhost', method, args=arg_dict)
if not result:
return ''
return jsonutils.loads(result)
except ValueError:
LOG.exception(_("Unable to get updated status"))
return None
except session.XenAPI.Failure as e:
LOG.error(_("The call to %(method)s returned "
"an error: %(e)s."), {'method': method, 'e': e})
return e.details[1]
def _uuid_find(context, host, name_label):
"""Return instance uuid by name_label."""
for i in instance_obj.InstanceList.get_by_host(context, host):
if i.name == name_label:
return i.uuid
return None
def _host_find(context, session, src_aggregate, dst):
"""Return the host from the xenapi host reference.
:param src_aggregate: the aggregate that the compute host being put in
maintenance (source of VMs) belongs to
:param dst: the hypervisor host reference (destination of VMs)
:return: the compute host that manages dst
"""
# NOTE: this would be a lot simpler if nova-compute stored
# CONF.host in the XenServer host's other-config map.
# TODO(armando-migliaccio): improve according the note above
uuid = session.call_xenapi('host.get_record', dst)['uuid']
for compute_host, host_uuid in src_aggregate.metadetails.iteritems():
if host_uuid == uuid:
return compute_host
raise exception.NoValidHost(reason='Host %(host_uuid)s could not be found '
'from aggregate metadata: %(metadata)s.' %
{'host_uuid': uuid,
'metadata': src_aggregate.metadetails})
|
