ceilometer/ceilometer/agent/base.py

252 lines
9.8 KiB
Python

#
# Copyright 2013 Julien Danjou
# Copyright 2014 Red Hat, Inc
#
# Authors: Julien Danjou <julien@danjou.info>
# Eoghan Glynn <eglynn@redhat.com>
# Nejc Saje <nsaje@redhat.com>
#
# 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 collections
import itertools
from oslo.config import cfg
import six
from six.moves.urllib import parse as urlparse
from stevedore import extension
from ceilometer import coordination
from ceilometer.i18n import _
from ceilometer.openstack.common import context
from ceilometer.openstack.common import log
from ceilometer.openstack.common import service as os_service
from ceilometer import pipeline as publish_pipeline
from ceilometer import utils
LOG = log.getLogger(__name__)
cfg.CONF.import_opt('heartbeat', 'ceilometer.coordination',
group='coordination')
class Resources(object):
def __init__(self, agent_manager):
self.agent_manager = agent_manager
self._resources = []
self._discovery = []
def setup(self, pipeline):
self._resources = pipeline.resources
self._discovery = pipeline.discovery
def get(self, discovery_cache=None):
source_discovery = (self.agent_manager.discover(self._discovery,
discovery_cache)
if self._discovery else [])
static_resources = []
if self._resources:
static_resources_group = self.agent_manager.construct_group_id(
utils.hash_of_set(self._resources))
p_coord = self.agent_manager.partition_coordinator
static_resources = p_coord.extract_my_subset(
static_resources_group, self._resources)
return static_resources + source_discovery
@staticmethod
def key(source_name, pollster):
return '%s-%s' % (source_name, pollster.name)
class PollingTask(object):
"""Polling task for polling samples and inject into pipeline.
A polling task can be invoked periodically or only once.
"""
def __init__(self, agent_manager):
self.manager = agent_manager
# elements of the Cartesian product of sources X pollsters
# with a common interval
self.pollster_matches = collections.defaultdict(set)
# per-sink publisher contexts associated with each source
self.publishers = {}
# we relate the static resources and per-source discovery to
# each combination of pollster and matching source
resource_factory = lambda: Resources(agent_manager)
self.resources = collections.defaultdict(resource_factory)
def add(self, pollster, pipeline):
if pipeline.source.name not in self.publishers:
publish_context = publish_pipeline.PublishContext(
self.manager.context)
self.publishers[pipeline.source.name] = publish_context
self.publishers[pipeline.source.name].add_pipelines([pipeline])
self.pollster_matches[pipeline.source.name].add(pollster)
key = Resources.key(pipeline.source.name, pollster)
self.resources[key].setup(pipeline)
def poll_and_publish(self):
"""Polling sample and publish into pipeline."""
cache = {}
discovery_cache = {}
for source_name in self.pollster_matches:
with self.publishers[source_name] as publisher:
for pollster in self.pollster_matches[source_name]:
LOG.info(_("Polling pollster %(poll)s in the context of "
"%(src)s"),
dict(poll=pollster.name, src=source_name))
pollster_resources = None
if pollster.obj.default_discovery:
pollster_resources = self.manager.discover(
[pollster.obj.default_discovery], discovery_cache)
key = Resources.key(source_name, pollster)
source_resources = list(
self.resources[key].get(discovery_cache))
polling_resources = (source_resources or
pollster_resources)
if not polling_resources:
LOG.info(_(
"Skip polling pollster %s, no resources found"),
pollster.name)
continue
try:
samples = list(pollster.obj.get_samples(
manager=self.manager,
cache=cache,
resources=polling_resources
))
publisher(samples)
except Exception as err:
LOG.warning(_(
'Continue after error from %(name)s: %(error)s')
% ({'name': pollster.name, 'error': err}),
exc_info=True)
class AgentManager(os_service.Service):
def __init__(self, namespace, group_prefix=None):
super(AgentManager, self).__init__()
self.pollster_manager = self._extensions('poll', namespace)
self.discovery_manager = self._extensions('discover')
self.context = context.RequestContext('admin', 'admin', is_admin=True)
self.partition_coordinator = coordination.PartitionCoordinator()
self.group_prefix = ('%s-%s' % (namespace, group_prefix)
if group_prefix else namespace)
@staticmethod
def _extensions(category, agent_ns=None):
namespace = ('ceilometer.%s.%s' % (category, agent_ns) if agent_ns
else 'ceilometer.%s' % category)
return extension.ExtensionManager(
namespace=namespace,
invoke_on_load=True,
)
def join_partitioning_groups(self):
groups = set([self.construct_group_id(d.obj.group_id)
for d in self.discovery_manager])
# let each set of statically-defined resources have its own group
static_resource_groups = set([
self.construct_group_id(utils.hash_of_set(p.resources))
for p in self.pipeline_manager.pipelines
if p.resources
])
groups.update(static_resource_groups)
for group in groups:
self.partition_coordinator.join_group(group)
def create_polling_task(self):
"""Create an initially empty polling task."""
return PollingTask(self)
def setup_polling_tasks(self):
polling_tasks = {}
for pipeline, pollster in itertools.product(
self.pipeline_manager.pipelines,
self.pollster_manager.extensions):
if pipeline.support_meter(pollster.name):
polling_task = polling_tasks.get(pipeline.get_interval())
if not polling_task:
polling_task = self.create_polling_task()
polling_tasks[pipeline.get_interval()] = polling_task
polling_task.add(pollster, pipeline)
return polling_tasks
def construct_group_id(self, discovery_group_id):
return ('%s-%s' % (self.group_prefix,
discovery_group_id)
if discovery_group_id else None)
def start(self):
self.pipeline_manager = publish_pipeline.setup_pipeline()
self.partition_coordinator.start()
self.join_partitioning_groups()
# allow time for coordination if necessary
delay_start = self.partition_coordinator.is_active()
for interval, task in six.iteritems(self.setup_polling_tasks()):
self.tg.add_timer(interval,
self.interval_task,
initial_delay=interval if delay_start else None,
task=task)
self.tg.add_timer(cfg.CONF.coordination.heartbeat,
self.partition_coordinator.heartbeat)
@staticmethod
def interval_task(task):
task.poll_and_publish()
@staticmethod
def _parse_discoverer(url):
s = urlparse.urlparse(url)
return (s.scheme or s.path), (s.netloc + s.path if s.scheme else None)
def _discoverer(self, name):
for d in self.discovery_manager:
if d.name == name:
return d.obj
return None
def discover(self, discovery=None, discovery_cache=None):
resources = []
discovery = discovery or []
for url in discovery:
if discovery_cache is not None and url in discovery_cache:
resources.extend(discovery_cache[url])
continue
name, param = self._parse_discoverer(url)
discoverer = self._discoverer(name)
if discoverer:
try:
discovered = discoverer.discover(self, param)
partitioned = self.partition_coordinator.extract_my_subset(
self.construct_group_id(discoverer.group_id),
discovered)
resources.extend(partitioned)
if discovery_cache is not None:
discovery_cache[url] = partitioned
except Exception as err:
LOG.exception(_('Unable to discover resources: %s') % err)
else:
LOG.warning(_('Unknown discovery extension: %s') % name)
return resources