deb-ceilometer/ceilometer/alarm/evaluator/gnocchi.py
Victor Stinner b7cd3a99b1 Fix Python 3 issue in opendaylight client
* Replace "resp.status_code / 100" with "resp.status_code // 100" to use
  integer division, not float division, on Python 3
* Replace also "int(status / 100)" with "status // 100" in other files

Change-Id: I609065529ffbfc718a7b382b191e588bd5ed3933
2015-07-31 15:20:12 +02:00

234 lines
8.8 KiB
Python

#
# Copyright 2015 eNovance
#
# 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 datetime
import operator
from oslo_config import cfg
from oslo_log import log
from oslo_serialization import jsonutils
from oslo_utils import timeutils
import requests
import six.moves
from ceilometer.alarm import evaluator
from ceilometer.i18n import _
from ceilometer import keystone_client
LOG = log.getLogger(__name__)
COMPARATORS = {
'gt': operator.gt,
'lt': operator.lt,
'ge': operator.ge,
'le': operator.le,
'eq': operator.eq,
'ne': operator.ne,
}
OPTS = [
cfg.StrOpt('gnocchi_url',
default="http://localhost:8041",
help='URL to Gnocchi.'),
]
cfg.CONF.register_opts(OPTS, group="alarms")
cfg.CONF.import_opt('http_timeout', 'ceilometer.service')
class GnocchiThresholdEvaluator(evaluator.Evaluator):
# the sliding evaluation window is extended to allow
# for reporting/ingestion lag
look_back = 1
# minimum number of datapoints within sliding window to
# avoid unknown state
quorum = 1
def __init__(self, notifier):
super(GnocchiThresholdEvaluator, self).__init__(notifier)
self.gnocchi_url = cfg.CONF.alarms.gnocchi_url
self._ks_client = None
@property
def ks_client(self):
if self._ks_client is None:
self._ks_client = keystone_client.get_client()
return self._ks_client
def _get_headers(self, content_type="application/json"):
return {
'Content-Type': content_type,
'X-Auth-Token': self.ks_client.auth_token,
}
def _statistics(self, alarm, start, end):
"""Retrieve statistics over the current window."""
method = 'get'
req = {
'url': self.gnocchi_url + "/v1",
'headers': self._get_headers(),
'params': {
'aggregation': alarm.rule['aggregation_method'],
'start': start,
'end': end,
}
}
if alarm.type == 'gnocchi_aggregation_by_resources_threshold':
method = 'post'
req['url'] += "/aggregation/resource/%s/metric/%s" % (
alarm.rule['resource_type'], alarm.rule['metric'])
req['data'] = alarm.rule['query']
elif alarm.type == 'gnocchi_aggregation_by_metrics_threshold':
req['url'] += "/aggregation/metric"
req['params']['metric[]'] = alarm.rule['metrics']
elif alarm.type == 'gnocchi_resources_threshold':
req['url'] += "/resource/%s/%s/metric/%s/measures" % (
alarm.rule['resource_type'],
alarm.rule['resource_id'], alarm.rule['metric'])
LOG.debug(_('stats query %s') % req['url'])
try:
r = getattr(requests, method)(**req)
except Exception:
LOG.exception(_('alarm stats retrieval failed'))
return []
if r.status_code // 100 != 2:
LOG.exception(_('alarm stats retrieval failed: %s') % r.text)
return []
else:
return jsonutils.loads(r.text)
@classmethod
def _bound_duration(cls, alarm):
"""Bound the duration of the statistics query."""
now = timeutils.utcnow()
# when exclusion of weak datapoints is enabled, we extend
# the look-back period so as to allow a clearer sample count
# trend to be established
window = (alarm.rule['granularity'] *
(alarm.rule['evaluation_periods'] + cls.look_back))
start = now - datetime.timedelta(seconds=window)
LOG.debug(_('query stats from %(start)s to '
'%(now)s') % {'start': start, 'now': now})
return start.isoformat(), now.isoformat()
def _sufficient(self, alarm, statistics):
"""Check for the sufficiency of the data for evaluation.
Ensure there is sufficient data for evaluation, transitioning to
unknown otherwise.
"""
sufficient = len(statistics) >= self.quorum
if not sufficient and alarm.state != evaluator.UNKNOWN:
reason = _('%d datapoints are unknown') % alarm.rule[
'evaluation_periods']
reason_data = self._reason_data('unknown',
alarm.rule['evaluation_periods'],
None)
self._refresh(alarm, evaluator.UNKNOWN, reason, reason_data)
return sufficient
@staticmethod
def _reason_data(disposition, count, most_recent):
"""Create a reason data dictionary for this evaluator type."""
return {'type': 'threshold', 'disposition': disposition,
'count': count, 'most_recent': most_recent}
@classmethod
def _reason(cls, alarm, statistics, distilled, state):
"""Fabricate reason string."""
count = len(statistics)
disposition = 'inside' if state == evaluator.OK else 'outside'
last = statistics[-1]
transition = alarm.state != state
reason_data = cls._reason_data(disposition, count, last)
if transition:
return (_('Transition to %(state)s due to %(count)d samples'
' %(disposition)s threshold, most recent:'
' %(most_recent)s')
% dict(reason_data, state=state)), reason_data
return (_('Remaining as %(state)s due to %(count)d samples'
' %(disposition)s threshold, most recent: %(most_recent)s')
% dict(reason_data, state=state)), reason_data
def _transition(self, alarm, statistics, compared):
"""Transition alarm state if necessary.
The transition rules are currently hardcoded as:
- transitioning from a known state requires an unequivocal
set of datapoints
- transitioning from unknown is on the basis of the most
recent datapoint if equivocal
Ultimately this will be policy-driven.
"""
distilled = all(compared)
unequivocal = distilled or not any(compared)
unknown = alarm.state == evaluator.UNKNOWN
continuous = alarm.repeat_actions
if unequivocal:
state = evaluator.ALARM if distilled else evaluator.OK
reason, reason_data = self._reason(alarm, statistics,
distilled, state)
if alarm.state != state or continuous:
self._refresh(alarm, state, reason, reason_data)
elif unknown or continuous:
trending_state = evaluator.ALARM if compared[-1] else evaluator.OK
state = trending_state if unknown else alarm.state
reason, reason_data = self._reason(alarm, statistics,
distilled, state)
self._refresh(alarm, state, reason, reason_data)
@staticmethod
def _select_best_granularity(alarm, statistics):
"""Return the datapoints that correspond to the alarm granularity"""
# TODO(sileht): if there's no direct match, but there is an archive
# policy with granularity that's an even divisor or the period,
# we could potentially do a mean-of-means (or max-of-maxes or whatever,
# but not a stddev-of-stddevs).
return [stats[2] for stats in statistics
if stats[1] == alarm.rule['granularity']]
def evaluate(self, alarm):
if not self.within_time_constraint(alarm):
LOG.debug(_('Attempted to evaluate alarm %s, but it is not '
'within its time constraint.') % alarm.alarm_id)
return
start, end = self._bound_duration(alarm)
statistics = self._statistics(alarm, start, end)
statistics = self._select_best_granularity(alarm, statistics)
if self._sufficient(alarm, statistics):
def _compare(value):
op = COMPARATORS[alarm.rule['comparison_operator']]
limit = alarm.rule['threshold']
LOG.debug(_('comparing value %(value)s against threshold'
' %(limit)s') %
{'value': value, 'limit': limit})
return op(value, limit)
self._transition(alarm,
statistics,
list(six.moves.map(_compare, statistics)))