9bad998a17
I was calculating the time to wait for the next run of a periodic task incorrectly. Resolves bug 1098819. Change-Id: Ida60b69014aa06229111e58024e35268262f18fb
319 lines
12 KiB
Python
319 lines
12 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
|
|
|
# Copyright 2010 United States Government as represented by the
|
|
# Administrator of the National Aeronautics and Space Administration.
|
|
# 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.
|
|
|
|
"""Base Manager class.
|
|
|
|
Managers are responsible for a certain aspect of the system. It is a logical
|
|
grouping of code relating to a portion of the system. In general other
|
|
components should be using the manager to make changes to the components that
|
|
it is responsible for.
|
|
|
|
For example, other components that need to deal with volumes in some way,
|
|
should do so by calling methods on the VolumeManager instead of directly
|
|
changing fields in the database. This allows us to keep all of the code
|
|
relating to volumes in the same place.
|
|
|
|
We have adopted a basic strategy of Smart managers and dumb data, which means
|
|
rather than attaching methods to data objects, components should call manager
|
|
methods that act on the data.
|
|
|
|
Methods on managers that can be executed locally should be called directly. If
|
|
a particular method must execute on a remote host, this should be done via rpc
|
|
to the service that wraps the manager
|
|
|
|
Managers should be responsible for most of the db access, and
|
|
non-implementation specific data. Anything implementation specific that can't
|
|
be generalized should be done by the Driver.
|
|
|
|
In general, we prefer to have one manager with multiple drivers for different
|
|
implementations, but sometimes it makes sense to have multiple managers. You
|
|
can think of it this way: Abstract different overall strategies at the manager
|
|
level(FlatNetwork vs VlanNetwork), and different implementations at the driver
|
|
level(LinuxNetDriver vs CiscoNetDriver).
|
|
|
|
Managers will often provide methods for initial setup of a host or periodic
|
|
tasks to a wrapping service.
|
|
|
|
This module provides Manager, a base class for managers.
|
|
|
|
"""
|
|
|
|
import eventlet
|
|
import time
|
|
|
|
from nova.db import base
|
|
from nova import exception
|
|
from nova.openstack.common import cfg
|
|
from nova.openstack.common import log as logging
|
|
from nova.openstack.common.plugin import pluginmanager
|
|
from nova.openstack.common.rpc import dispatcher as rpc_dispatcher
|
|
from nova.scheduler import rpcapi as scheduler_rpcapi
|
|
from nova import version
|
|
|
|
|
|
periodic_opts = [
|
|
cfg.BoolOpt('run_external_periodic_tasks',
|
|
default=True,
|
|
help=('Some periodic tasks can be run in a separate process. '
|
|
'Should we run them here?')),
|
|
]
|
|
|
|
CONF = cfg.CONF
|
|
CONF.register_opts(periodic_opts)
|
|
CONF.import_opt('host', 'nova.netconf')
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
DEFAULT_INTERVAL = 60.0
|
|
|
|
|
|
def periodic_task(*args, **kwargs):
|
|
"""Decorator to indicate that a method is a periodic task.
|
|
|
|
This decorator can be used in two ways:
|
|
|
|
1. Without arguments '@periodic_task', this will be run on every cycle
|
|
of the periodic scheduler.
|
|
|
|
2. With arguments, @periodic_task(periodic_spacing=N), this will be
|
|
run on approximately every N seconds. If this number is negative the
|
|
periodic task will be disabled.
|
|
"""
|
|
def decorator(f):
|
|
# Test for old style invocation
|
|
if 'ticks_between_runs' in kwargs:
|
|
raise exception.InvalidPeriodicTaskArg(arg='ticks_between_runs')
|
|
|
|
# Control if run at all
|
|
f._periodic_task = True
|
|
f._periodic_external_ok = kwargs.pop('external_process_ok', False)
|
|
if f._periodic_external_ok and not CONF.run_external_periodic_tasks:
|
|
f._periodic_enabled = False
|
|
else:
|
|
f._periodic_enabled = kwargs.pop('enabled', True)
|
|
|
|
# Control frequency
|
|
f._periodic_spacing = kwargs.pop('spacing', 0)
|
|
f._periodic_last_run = time.time()
|
|
return f
|
|
|
|
# NOTE(sirp): The `if` is necessary to allow the decorator to be used with
|
|
# and without parens.
|
|
#
|
|
# In the 'with-parens' case (with kwargs present), this function needs to
|
|
# return a decorator function since the interpreter will invoke it like:
|
|
#
|
|
# periodic_task(*args, **kwargs)(f)
|
|
#
|
|
# In the 'without-parens' case, the original function will be passed
|
|
# in as the first argument, like:
|
|
#
|
|
# periodic_task(f)
|
|
if kwargs:
|
|
return decorator
|
|
else:
|
|
return decorator(args[0])
|
|
|
|
|
|
class ManagerMeta(type):
|
|
def __init__(cls, names, bases, dict_):
|
|
"""Metaclass that allows us to collect decorated periodic tasks."""
|
|
super(ManagerMeta, cls).__init__(names, bases, dict_)
|
|
|
|
# NOTE(sirp): if the attribute is not present then we must be the base
|
|
# class, so, go ahead an initialize it. If the attribute is present,
|
|
# then we're a subclass so make a copy of it so we don't step on our
|
|
# parent's toes.
|
|
try:
|
|
cls._periodic_tasks = cls._periodic_tasks[:]
|
|
except AttributeError:
|
|
cls._periodic_tasks = []
|
|
|
|
try:
|
|
cls._periodic_last_run = cls._periodic_last_run.copy()
|
|
except AttributeError:
|
|
cls._periodic_last_run = {}
|
|
|
|
try:
|
|
cls._periodic_spacing = cls._periodic_spacing.copy()
|
|
except AttributeError:
|
|
cls._periodic_spacing = {}
|
|
|
|
for value in cls.__dict__.values():
|
|
if getattr(value, '_periodic_task', False):
|
|
task = value
|
|
name = task.__name__
|
|
|
|
if task._periodic_spacing < 0:
|
|
LOG.info(_('Skipping periodic task %(task)s because '
|
|
'its interval is negative'),
|
|
{'task': name})
|
|
continue
|
|
if not task._periodic_enabled:
|
|
LOG.info(_('Skipping periodic task %(task)s because '
|
|
'it is disabled'),
|
|
{'task': name})
|
|
continue
|
|
|
|
# A periodic spacing of zero indicates that this task should
|
|
# be run every pass
|
|
if task._periodic_spacing == 0:
|
|
task._periodic_spacing = None
|
|
|
|
cls._periodic_tasks.append((name, task))
|
|
cls._periodic_spacing[name] = task._periodic_spacing
|
|
cls._periodic_last_run[name] = task._periodic_last_run
|
|
|
|
|
|
class Manager(base.Base):
|
|
__metaclass__ = ManagerMeta
|
|
|
|
# Set RPC API version to 1.0 by default.
|
|
RPC_API_VERSION = '1.0'
|
|
|
|
def __init__(self, host=None, db_driver=None):
|
|
if not host:
|
|
host = CONF.host
|
|
self.host = host
|
|
self.load_plugins()
|
|
self.backdoor_port = None
|
|
super(Manager, self).__init__(db_driver)
|
|
|
|
def load_plugins(self):
|
|
pluginmgr = pluginmanager.PluginManager('nova', self.__class__)
|
|
pluginmgr.load_plugins()
|
|
|
|
def create_rpc_dispatcher(self):
|
|
'''Get the rpc dispatcher for this manager.
|
|
|
|
If a manager would like to set an rpc API version, or support more than
|
|
one class as the target of rpc messages, override this method.
|
|
'''
|
|
return rpc_dispatcher.RpcDispatcher([self])
|
|
|
|
def periodic_tasks(self, context, raise_on_error=False):
|
|
"""Tasks to be run at a periodic interval."""
|
|
idle_for = DEFAULT_INTERVAL
|
|
for task_name, task in self._periodic_tasks:
|
|
full_task_name = '.'.join([self.__class__.__name__, task_name])
|
|
|
|
# If a periodic task is _nearly_ due, then we'll run it early
|
|
if self._periodic_spacing[task_name] is None:
|
|
wait = 0
|
|
else:
|
|
due = (self._periodic_last_run[task_name] +
|
|
self._periodic_spacing[task_name])
|
|
wait = max(0, due - time.time())
|
|
if wait > 0.2:
|
|
if wait < idle_for:
|
|
idle_for = wait
|
|
continue
|
|
|
|
LOG.debug(_("Running periodic task %(full_task_name)s"), locals())
|
|
self._periodic_last_run[task_name] = time.time()
|
|
|
|
try:
|
|
task(self, context)
|
|
except Exception as e:
|
|
if raise_on_error:
|
|
raise
|
|
LOG.exception(_("Error during %(full_task_name)s: %(e)s"),
|
|
locals())
|
|
|
|
if (not self._periodic_spacing[task_name] is None and
|
|
self._periodic_spacing[task_name] < idle_for):
|
|
idle_for = self._periodic_spacing[task_name]
|
|
eventlet.sleep(0)
|
|
|
|
return idle_for
|
|
|
|
def init_host(self):
|
|
"""Hook to do additional manager initialization when one requests
|
|
the service be started. This is called before any service record
|
|
is created.
|
|
|
|
Child classes should override this method.
|
|
"""
|
|
pass
|
|
|
|
def pre_start_hook(self, **kwargs):
|
|
"""Hook to provide the manager the ability to do additional
|
|
start-up work before any RPC queues/consumers are created. This is
|
|
called after other initialization has succeeded and a service
|
|
record is created.
|
|
|
|
Child classes should override this method.
|
|
"""
|
|
pass
|
|
|
|
def post_start_hook(self):
|
|
"""Hook to provide the manager the ability to do additional
|
|
start-up work immediately after a service creates RPC consumers
|
|
and starts 'running'.
|
|
|
|
Child classes should override this method.
|
|
"""
|
|
pass
|
|
|
|
def service_version(self, context):
|
|
return version.version_string()
|
|
|
|
def service_config(self, context):
|
|
config = {}
|
|
for key in CONF:
|
|
config[key] = CONF.get(key, None)
|
|
return config
|
|
|
|
|
|
class SchedulerDependentManager(Manager):
|
|
"""Periodically send capability updates to the Scheduler services.
|
|
|
|
Services that need to update the Scheduler of their capabilities
|
|
should derive from this class. Otherwise they can derive from
|
|
manager.Manager directly. Updates are only sent after
|
|
update_service_capabilities is called with non-None values.
|
|
|
|
"""
|
|
|
|
def __init__(self, host=None, db_driver=None, service_name='undefined'):
|
|
self.last_capabilities = None
|
|
self.service_name = service_name
|
|
self.scheduler_rpcapi = scheduler_rpcapi.SchedulerAPI()
|
|
super(SchedulerDependentManager, self).__init__(host, db_driver)
|
|
|
|
def load_plugins(self):
|
|
pluginmgr = pluginmanager.PluginManager('nova', self.service_name)
|
|
pluginmgr.load_plugins()
|
|
|
|
def update_service_capabilities(self, capabilities):
|
|
"""Remember these capabilities to send on next periodic update."""
|
|
if not isinstance(capabilities, list):
|
|
capabilities = [capabilities]
|
|
self.last_capabilities = capabilities
|
|
|
|
@periodic_task
|
|
def publish_service_capabilities(self, context):
|
|
"""Pass data back to the scheduler.
|
|
|
|
Called at a periodic interval. And also called via rpc soon after
|
|
the start of the scheduler.
|
|
"""
|
|
if self.last_capabilities:
|
|
LOG.debug(_('Notifying Schedulers of capabilities ...'))
|
|
self.scheduler_rpcapi.update_service_capabilities(context,
|
|
self.service_name, self.host, self.last_capabilities)
|