masakari/masakari/engine/drivers/taskflow/host_failure.py

261 lines
11 KiB
Python

# Copyright 2016 NTT DATA
# All Rights Reserved.
#
# 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.
import eventlet
from eventlet import timeout as etimeout
from oslo_log import log as logging
from oslo_service import loopingcall
from oslo_utils import strutils
import taskflow.engines
from taskflow.patterns import linear_flow
from taskflow import retry
import masakari.conf
from masakari.engine.drivers.taskflow import base
from masakari import exception
from masakari.i18n import _, _LI
from masakari import utils
CONF = masakari.conf.CONF
LOG = logging.getLogger(__name__)
ACTION = 'instance:evacuate'
class DisableComputeServiceTask(base.MasakariTask):
def __init__(self, novaclient):
requires = ["host_name"]
super(DisableComputeServiceTask, self).__init__(addons=[ACTION],
requires=requires)
self.novaclient = novaclient
def execute(self, context, host_name):
self.novaclient.enable_disable_service(context, host_name)
# Sleep until nova-compute service is marked as disabled.
msg = _LI("Sleeping %(wait)s sec before starting recovery "
"thread until nova recognizes the node down.")
LOG.info(msg, {'wait': CONF.wait_period_after_service_update})
eventlet.sleep(CONF.wait_period_after_service_update)
class PrepareHAEnabledInstancesTask(base.MasakariTask):
"""Get all HA_Enabled instances."""
default_provides = set(["instance_list"])
def __init__(self, novaclient):
requires = ["host_name"]
super(PrepareHAEnabledInstancesTask, self).__init__(addons=[ACTION],
requires=requires)
self.novaclient = novaclient
def execute(self, context, host_name):
instance_list = self.novaclient.get_servers(context, host_name)
if CONF.host_failure.evacuate_all_instances:
instance_list = sorted(
instance_list, key=lambda k: strutils.bool_from_string(
k.metadata.get('HA_Enabled', False)), reverse=True)
else:
instance_list = (
[instance for instance in instance_list if
strutils.bool_from_string(instance.metadata.get('HA_Enabled',
False))])
if not instance_list:
msg = _('No instances to evacuate on host: %s.') % host_name
LOG.info(msg)
raise exception.SkipHostRecoveryException(message=msg)
return {
"instance_list": instance_list,
}
class EvacuateInstancesTask(base.MasakariTask):
default_provides = set(["instance_list"])
def __init__(self, novaclient):
requires = ["host_name", "instance_list"]
super(EvacuateInstancesTask, self).__init__(addons=[ACTION],
requires=requires)
self.novaclient = novaclient
def execute(self, context, host_name, instance_list, reserved_host=None):
def _do_evacuate(context, host_name, instance_list,
reserved_host=None):
if reserved_host:
if CONF.host_failure.add_reserved_host_to_aggregate:
# Assign reserved_host to an aggregate to which the failed
# compute host belongs to.
aggregates = self.novaclient.get_aggregate_list(context)
for aggregate in aggregates:
if host_name in aggregate.hosts:
self.novaclient.add_host_to_aggregate(
context, reserved_host.name, aggregate)
# A failed compute host can be associated with
# multiple aggregates but operators will not
# associate it with multiple aggregates in real
# deployment so adding reserved_host to the very
# first aggregate from the list.
break
self.novaclient.enable_disable_service(
context, reserved_host.name, enable=True)
# Sleep until nova-compute service is marked as enabled.
msg = _LI("Sleeping %(wait)s sec before starting recovery "
"thread until nova recognizes the node up.")
LOG.info(msg, {
'wait': CONF.wait_period_after_service_update})
eventlet.sleep(CONF.wait_period_after_service_update)
# Set reserved property of reserved_host to False
reserved_host.reserved = False
reserved_host.save()
for instance in instance_list:
vm_state = getattr(instance, "OS-EXT-STS:vm_state")
if vm_state in ['active', 'error', 'resized', 'stopped']:
# Evacuate API only evacuates an instance in
# active, stop or error state. If an instance is in
# resized status, masakari resets the instance
# state to *error* to evacuate it.
if vm_state == 'resized':
self.novaclient.reset_instance_state(
context, instance.id)
# evacuate the instance
self.novaclient.evacuate_instance(
context, instance.id,
target=reserved_host.name if reserved_host else None)
lock_name = reserved_host.name if reserved_host else None
@utils.synchronized(lock_name)
def do_evacuate_with_reserved_host(context, host_name, instance_list,
reserved_host):
_do_evacuate(context, host_name, instance_list,
reserved_host=reserved_host)
if lock_name:
do_evacuate_with_reserved_host(context, host_name, instance_list,
reserved_host)
else:
# No need to acquire lock on reserved_host when recovery_method is
# 'auto' as the selection of compute host will be decided by nova.
_do_evacuate(context, host_name, instance_list)
return {
"instance_list": instance_list,
}
class ConfirmEvacuationTask(base.MasakariTask):
def __init__(self, novaclient):
requires = ["instance_list", "host_name"]
super(ConfirmEvacuationTask, self).__init__(addons=[ACTION],
requires=requires)
self.novaclient = novaclient
def execute(self, context, instance_list, host_name):
failed_evacuation_instances = []
for instance in instance_list:
def _wait_for_evacuation():
new_instance = self.novaclient.get_server(context, instance.id)
instance_host = getattr(new_instance,
"OS-EXT-SRV-ATTR:hypervisor_hostname")
old_vm_state = getattr(instance, "OS-EXT-STS:vm_state")
new_vm_state = getattr(new_instance,
"OS-EXT-STS:vm_state")
if instance_host != host_name:
if ((old_vm_state == 'error' and
new_vm_state == 'active') or
old_vm_state == new_vm_state):
raise loopingcall.LoopingCallDone()
periodic_call = loopingcall.FixedIntervalLoopingCall(
_wait_for_evacuation)
try:
# add a timeout to the periodic call.
periodic_call.start(interval=CONF.verify_interval)
etimeout.with_timeout(CONF.wait_period_after_evacuation,
periodic_call.wait)
except etimeout.Timeout:
# Instance is not evacuated in the expected time_limit.
failed_evacuation_instances.append(instance.id)
finally:
# stop the periodic call, in case of exceptions or Timeout.
periodic_call.stop()
if failed_evacuation_instances:
msg = _("Failed to evacuate instances %(instances)s from "
"host %(host_name)s.") % {
'instances': failed_evacuation_instances,
'host_name': host_name
}
raise exception.HostRecoveryFailureException(message=msg)
def get_auto_flow(novaclient, process_what):
"""Constructs and returns the engine entrypoint flow.
This flow will do the following:
1. Disable compute service on source host
2. Get all HA_Enabled instances.
3. Evacuate all the HA_Enabled instances.
4. Confirm evacuation of instances.
"""
flow_name = ACTION.replace(":", "_") + "_engine"
auto_evacuate_flow = linear_flow.Flow(flow_name)
auto_evacuate_flow.add(DisableComputeServiceTask(novaclient),
PrepareHAEnabledInstancesTask(novaclient),
EvacuateInstancesTask(novaclient),
ConfirmEvacuationTask(novaclient))
return taskflow.engines.load(auto_evacuate_flow, store=process_what)
def get_rh_flow(novaclient, process_what):
"""Constructs and returns the engine entrypoint flow.
This flow will do the following:
1. Disable compute service on source host
2. Get all HA_Enabled instances.
3. Evacuate all the HA_Enabled instances using reserved_host.
4. Confirm evacuation of instances.
"""
flow_name = ACTION.replace(":", "_") + "_engine"
nested_flow = linear_flow.Flow(flow_name)
rh_flow = linear_flow.Flow(
"retry_%s" % flow_name, retry=retry.ParameterizedForEach(
rebind=['reserved_host_list'], provides='reserved_host'))
rh_flow.add(PrepareHAEnabledInstancesTask(novaclient),
EvacuateInstancesTask(novaclient),
ConfirmEvacuationTask(novaclient))
nested_flow.add(DisableComputeServiceTask(novaclient), rh_flow)
return taskflow.engines.load(nested_flow, store=process_what)