neutron/neutron/service.py

454 lines
15 KiB
Python

# Copyright 2011 VMware, Inc
# 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 inspect
import os
import random
from neutron_lib.callbacks import events
from neutron_lib.callbacks import registry
from neutron_lib.callbacks import resources
from neutron_lib import context
from neutron_lib.db import api as session
from neutron_lib.plugins import directory
from neutron_lib import rpc as n_rpc
from oslo_concurrency import processutils
from oslo_config import cfg
from oslo_log import log as logging
from oslo_messaging import server as rpc_server
from oslo_service import loopingcall
from oslo_service import service as common_service
from oslo_utils import excutils
from oslo_utils import importutils
import psutil
from neutron.common import config
from neutron.common import profiler
from neutron.conf import service
from neutron import worker as neutron_worker
from neutron import wsgi
service.register_service_opts(service.SERVICE_OPTS)
service.register_service_opts(service.RPC_EXTRA_OPTS)
LOG = logging.getLogger(__name__)
class WsgiService(object):
"""Base class for WSGI based services.
For each api you define, you must also define these flags:
:<api>_listen: The address on which to listen
:<api>_listen_port: The port on which to listen
"""
def __init__(self, app_name):
self.app_name = app_name
self.wsgi_app = None
def start(self):
self.wsgi_app = _run_wsgi(self.app_name)
def wait(self):
self.wsgi_app.wait()
class NeutronApiService(WsgiService):
"""Class for neutron-api service."""
def __init__(self, app_name):
profiler.setup('neutron-server', cfg.CONF.host)
super(NeutronApiService, self).__init__(app_name)
@classmethod
def create(cls, app_name='neutron'):
service = cls(app_name)
return service
def serve_wsgi(cls):
try:
service = cls.create()
service.start()
except Exception:
with excutils.save_and_reraise_exception():
LOG.exception('Unrecoverable error: please check log '
'for details.')
registry.publish(resources.PROCESS, events.BEFORE_SPAWN, service)
return service
class RpcWorker(neutron_worker.NeutronBaseWorker):
"""Wraps a worker to be handled by ProcessLauncher"""
start_listeners_method = 'start_rpc_listeners'
def __init__(self, plugins, worker_process_count=1):
super(RpcWorker, self).__init__(
worker_process_count=worker_process_count
)
self._plugins = plugins
self._servers = []
def start(self):
super(RpcWorker, self).start(desc="rpc worker")
for plugin in self._plugins:
if hasattr(plugin, self.start_listeners_method):
try:
servers = getattr(plugin, self.start_listeners_method)()
except NotImplementedError:
continue
self._servers.extend(servers)
def wait(self):
try:
self._wait()
except Exception:
LOG.exception('done with wait')
raise
def _wait(self):
LOG.debug('calling RpcWorker wait()')
for server in self._servers:
if isinstance(server, rpc_server.MessageHandlingServer):
LOG.debug('calling wait on %s', server)
server.wait()
else:
LOG.debug('NOT calling wait on %s', server)
LOG.debug('returning from RpcWorker wait()')
def stop(self):
LOG.debug('calling RpcWorker stop()')
for server in self._servers:
if isinstance(server, rpc_server.MessageHandlingServer):
LOG.debug('calling stop on %s', server)
server.stop()
@staticmethod
def reset():
config.reset_service()
class RpcReportsWorker(RpcWorker):
start_listeners_method = 'start_rpc_state_reports_listener'
def _get_worker_count():
# Start with the number of CPUs
num_workers = processutils.get_worker_count()
# Now don't use more than half the system memory, assuming
# a steady-state bloat of around 2GB.
mem = psutil.virtual_memory()
mem_workers = int(mem.total / (2 * 1024 * 1024 * 1024))
if mem_workers < num_workers:
num_workers = mem_workers
# And just in case, always at least one.
if num_workers <= 0:
num_workers = 1
return num_workers
def _get_rpc_workers(plugin=None):
if plugin is None:
plugin = directory.get_plugin()
service_plugins = directory.get_plugins().values()
workers = cfg.CONF.rpc_workers
if workers is None:
# By default, half as many rpc workers as api workers
workers = int(_get_api_workers() / 2)
workers = max(workers, 1)
# If workers > 0 then start_rpc_listeners would be called in a
# subprocess and we cannot simply catch the NotImplementedError. It is
# simpler to check this up front by testing whether the plugin supports
# multiple RPC workers.
if not plugin.rpc_workers_supported():
LOG.debug("Active plugin doesn't implement start_rpc_listeners")
if workers > 0:
LOG.error("'rpc_workers = %d' ignored because "
"start_rpc_listeners is not implemented.",
workers)
raise NotImplementedError()
# passing service plugins only, because core plugin is among them
rpc_workers = [RpcWorker(service_plugins,
worker_process_count=workers)]
if (cfg.CONF.rpc_state_report_workers > 0 and
plugin.rpc_state_report_workers_supported()):
rpc_workers.append(
RpcReportsWorker(
[plugin],
worker_process_count=cfg.CONF.rpc_state_report_workers
)
)
return rpc_workers
def _get_plugins_workers():
# NOTE(twilson) get_plugins also returns the core plugin
plugins = directory.get_unique_plugins()
# TODO(twilson) Instead of defaulting here, come up with a good way to
# share a common get_workers default between NeutronPluginBaseV2 and
# ServicePluginBase
return [
plugin_worker
for plugin in plugins if hasattr(plugin, 'get_workers')
for plugin_worker in plugin.get_workers()
]
class AllServicesNeutronWorker(neutron_worker.NeutronBaseWorker):
def __init__(self, services, worker_process_count=1):
super(AllServicesNeutronWorker, self).__init__(worker_process_count)
self._services = services
self._launcher = common_service.Launcher(cfg.CONF,
restart_method='mutate')
def start(self):
for srv in self._services:
self._launcher.launch_service(srv)
super(AllServicesNeutronWorker, self).start(desc="services worker")
def stop(self):
self._launcher.stop()
def wait(self):
self._launcher.wait()
def reset(self):
self._launcher.restart()
def _start_workers(workers, neutron_api=None):
process_workers = [
plugin_worker for plugin_worker in workers
if plugin_worker.worker_process_count > 0
]
try:
if process_workers:
# Get eventual already existing instance from WSGI app
worker_launcher = None
if neutron_api:
worker_launcher = neutron_api.wsgi_app.process_launcher
if worker_launcher is None:
worker_launcher = common_service.ProcessLauncher(
cfg.CONF, wait_interval=1.0, restart_method='mutate'
)
# add extra process worker and spawn there all workers with
# worker_process_count == 0
thread_workers = [
plugin_worker for plugin_worker in workers
if plugin_worker.worker_process_count < 1
]
if thread_workers:
process_workers.append(
AllServicesNeutronWorker(thread_workers)
)
# dispose the whole pool before os.fork, otherwise there will
# be shared DB connections in child processes which may cause
# DB errors.
session.get_context_manager().dispose_pool()
for worker in process_workers:
worker_launcher.launch_service(worker,
worker.worker_process_count)
else:
worker_launcher = common_service.ServiceLauncher(cfg.CONF)
for worker in workers:
worker_launcher.launch_service(worker)
return worker_launcher
except Exception:
with excutils.save_and_reraise_exception():
LOG.exception('Unrecoverable error: please check log for '
'details.')
def start_all_workers(neutron_api=None):
workers = _get_rpc_workers() + _get_plugins_workers()
launcher = _start_workers(workers, neutron_api)
registry.publish(resources.PROCESS, events.AFTER_SPAWN, None)
return launcher
def start_rpc_workers():
rpc_workers = _get_rpc_workers()
LOG.debug('using launcher for rpc, workers=%s', cfg.CONF.rpc_workers)
launcher = _start_workers(rpc_workers)
registry.publish(resources.PROCESS, events.AFTER_SPAWN, None)
return launcher
def start_plugins_workers():
plugins_workers = _get_plugins_workers()
return _start_workers(plugins_workers)
def _get_api_workers():
workers = cfg.CONF.api_workers
if workers is None:
workers = _get_worker_count()
return workers
def _run_wsgi(app_name):
app = config.load_paste_app(app_name)
if not app:
LOG.error('No known API applications configured.')
return
return run_wsgi_app(app)
def run_wsgi_app(app):
server = wsgi.Server("Neutron")
server.start(app, cfg.CONF.bind_port, cfg.CONF.bind_host,
workers=_get_api_workers(), desc="api worker")
LOG.info("Neutron service started, listening on %(host)s:%(port)s",
{'host': cfg.CONF.bind_host, 'port': cfg.CONF.bind_port})
return server
class Service(n_rpc.Service):
"""Service object for binaries running on hosts.
A service takes a manager and enables rpc by listening to queues based
on topic. It also periodically runs tasks on the manager.
"""
def __init__(self, host, binary, topic, manager, report_interval=None,
periodic_interval=None, periodic_fuzzy_delay=None,
*args, **kwargs):
self.binary = binary
self.manager_class_name = manager
manager_class = importutils.import_class(self.manager_class_name)
self.manager = manager_class(host=host, *args, **kwargs)
self.report_interval = report_interval
self.periodic_interval = periodic_interval
self.periodic_fuzzy_delay = periodic_fuzzy_delay
self.saved_args, self.saved_kwargs = args, kwargs
self.timers = []
profiler.setup(binary, host)
super(Service, self).__init__(host, topic, manager=self.manager)
def start(self):
self.manager.init_host()
super(Service, self).start()
if self.report_interval:
pulse = loopingcall.FixedIntervalLoopingCall(self.report_state)
pulse.start(interval=self.report_interval,
initial_delay=self.report_interval)
self.timers.append(pulse)
if self.periodic_interval:
if self.periodic_fuzzy_delay:
initial_delay = random.randint(0, self.periodic_fuzzy_delay)
else:
initial_delay = None
periodic = loopingcall.FixedIntervalLoopingCall(
self.periodic_tasks)
periodic.start(interval=self.periodic_interval,
initial_delay=initial_delay)
self.timers.append(periodic)
self.manager.after_start()
def __getattr__(self, key):
manager = self.__dict__.get('manager', None)
return getattr(manager, key)
@classmethod
def create(cls, host=None, binary=None, topic=None, manager=None,
report_interval=None, periodic_interval=None,
periodic_fuzzy_delay=None):
"""Instantiates class and passes back application object.
:param host: defaults to cfg.CONF.host
:param binary: defaults to basename of executable
:param topic: defaults to bin_name - 'neutron-' part
:param manager: defaults to cfg.CONF.<topic>_manager
:param report_interval: defaults to cfg.CONF.report_interval
:param periodic_interval: defaults to cfg.CONF.periodic_interval
:param periodic_fuzzy_delay: defaults to cfg.CONF.periodic_fuzzy_delay
"""
if not host:
host = cfg.CONF.host
if not binary:
binary = os.path.basename(inspect.stack()[-1][1])
if not topic:
topic = binary.rpartition('neutron-')[2]
topic = topic.replace("-", "_")
if not manager:
manager = cfg.CONF.get('%s_manager' % topic, None)
if report_interval is None:
report_interval = cfg.CONF.report_interval
if periodic_interval is None:
periodic_interval = cfg.CONF.periodic_interval
if periodic_fuzzy_delay is None:
periodic_fuzzy_delay = cfg.CONF.periodic_fuzzy_delay
service_obj = cls(host, binary, topic, manager,
report_interval=report_interval,
periodic_interval=periodic_interval,
periodic_fuzzy_delay=periodic_fuzzy_delay)
return service_obj
def kill(self):
"""Destroy the service object."""
self.stop()
def stop(self):
super(Service, self).stop()
for x in self.timers:
try:
x.stop()
except Exception:
LOG.exception("Exception occurs when timer stops")
self.timers = []
self.manager.stop()
def wait(self):
super(Service, self).wait()
for x in self.timers:
try:
x.wait()
except Exception:
LOG.exception("Exception occurs when waiting for timer")
def reset(self):
config.reset_service()
def periodic_tasks(self, raise_on_error=False):
"""Tasks to be run at a periodic interval."""
ctxt = context.get_admin_context()
self.manager.periodic_tasks(ctxt, raise_on_error=raise_on_error)
def report_state(self):
"""Update the state of this service."""
# Todo(gongysh) report state to neutron server
pass