Source code for ceilometer.transformer.conversions

#
# Copyright 2013 Red Hat, Inc
#
# 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 re

from oslo_log import log
from oslo_utils import timeutils
import six

from ceilometer.i18n import _, _LW
from ceilometer import sample
from ceilometer import transformer

LOG = log.getLogger(__name__)


[docs]class BaseConversionTransformer(transformer.TransformerBase): """Transformer to derive conversion.""" grouping_keys = ['resource_id'] def __init__(self, source=None, target=None, **kwargs): """Initialize transformer with configured parameters. :param source: dict containing source sample unit :param target: dict containing target sample name, type, unit and scaling factor (a missing value connotes no change) """ self.source = source or {} self.target = target or {} super(BaseConversionTransformer, self).__init__(**kwargs) def _map(self, s, attr): """Apply the name or unit mapping if configured.""" mapped = None from_ = self.source.get('map_from') to_ = self.target.get('map_to') if from_ and to_: if from_.get(attr) and to_.get(attr): try: mapped = re.sub(from_[attr], to_[attr], getattr(s, attr)) except Exception: pass return mapped or self.target.get(attr, getattr(s, attr))
[docs]class DeltaTransformer(BaseConversionTransformer): """Transformer based on the delta of a sample volume.""" def __init__(self, target=None, growth_only=False, **kwargs): """Initialize transformer with configured parameters. :param growth_only: capture only positive deltas """ super(DeltaTransformer, self).__init__(target=target, **kwargs) self.growth_only = growth_only self.cache = {}
[docs] def handle_sample(self, s): """Handle a sample, converting if necessary.""" key = s.name + s.resource_id prev = self.cache.get(key) timestamp = timeutils.parse_isotime(s.timestamp) self.cache[key] = (s.volume, timestamp) if prev: prev_volume = prev[0] prev_timestamp = prev[1] time_delta = timeutils.delta_seconds(prev_timestamp, timestamp) # disallow violations of the arrow of time if time_delta < 0: LOG.warning(_LW('Dropping out of time order sample: %s'), (s,)) # Reset the cache to the newer sample. self.cache[key] = prev return None volume_delta = s.volume - prev_volume if self.growth_only and volume_delta < 0: LOG.warning(_LW('Negative delta detected, dropping value')) s = None else: s = self._convert(s, volume_delta) LOG.debug('Converted to: %s', s) else: LOG.warning(_LW('Dropping sample with no predecessor: %s'), (s,)) s = None return s
def _convert(self, s, delta): """Transform the appropriate sample fields.""" return sample.Sample( name=self._map(s, 'name'), unit=s.unit, type=sample.TYPE_DELTA, volume=delta, user_id=s.user_id, project_id=s.project_id, resource_id=s.resource_id, timestamp=s.timestamp, resource_metadata=s.resource_metadata )
[docs]class ScalingTransformer(BaseConversionTransformer): """Transformer to apply a scaling conversion.""" def __init__(self, source=None, target=None, **kwargs): """Initialize transformer with configured parameters. :param source: dict containing source sample unit :param target: dict containing target sample name, type, unit and scaling factor (a missing value connotes no change) """ super(ScalingTransformer, self).__init__(source=source, target=target, **kwargs) self.scale = self.target.get('scale') LOG.debug('scaling conversion transformer with source:' ' %(source)s target: %(target)s:', {'source': self.source, 'target': self.target}) def _scale(self, s): """Apply the scaling factor. Either a straight multiplicative factor or else a string to be eval'd. """ ns = transformer.Namespace(s.as_dict()) scale = self.scale return ((eval(scale, {}, ns) if isinstance(scale, six.string_types) else s.volume * scale) if scale else s.volume) def _convert(self, s, growth=1): """Transform the appropriate sample fields.""" return sample.Sample( name=self._map(s, 'name'), unit=self._map(s, 'unit'), type=self.target.get('type', s.type), volume=self._scale(s) * growth, user_id=s.user_id, project_id=s.project_id, resource_id=s.resource_id, timestamp=s.timestamp, resource_metadata=s.resource_metadata )
[docs] def handle_sample(self, s): """Handle a sample, converting if necessary.""" LOG.debug('handling sample %s', s) if self.source.get('unit', s.unit) == s.unit: s = self._convert(s) LOG.debug('converted to: %s', s) return s
[docs]class RateOfChangeTransformer(ScalingTransformer): """Transformer based on the rate of change of a sample volume. For example, taking the current and previous volumes of a cumulative sample and producing a gauge value based on the proportion of some maximum used. """ def __init__(self, **kwargs): """Initialize transformer with configured parameters.""" super(RateOfChangeTransformer, self).__init__(**kwargs) self.cache = {} self.scale = self.scale or '1'
[docs] def handle_sample(self, s): """Handle a sample, converting if necessary.""" LOG.debug('handling sample %s', s) key = s.name + s.resource_id prev = self.cache.get(key) timestamp = timeutils.parse_isotime(s.timestamp) self.cache[key] = (s.volume, timestamp) if prev: prev_volume = prev[0] prev_timestamp = prev[1] time_delta = timeutils.delta_seconds(prev_timestamp, timestamp) # disallow violations of the arrow of time if time_delta < 0: LOG.warning(_('dropping out of time order sample: %s'), (s,)) # Reset the cache to the newer sample. self.cache[key] = prev return None # we only allow negative volume deltas for noncumulative # samples, whereas for cumulative we assume that a reset has # occurred in the interim so that the current volume gives a # lower bound on growth volume_delta = (s.volume - prev_volume if (prev_volume <= s.volume or s.type != sample.TYPE_CUMULATIVE) else s.volume) rate_of_change = ((1.0 * volume_delta / time_delta) if time_delta else 0.0) s = self._convert(s, rate_of_change) LOG.debug('converted to: %s', s) else: LOG.warning(_('dropping sample with no predecessor: %s'), (s,)) s = None return s
[docs]class AggregatorTransformer(ScalingTransformer): """Transformer that aggregates samples. Aggregation goes until a threshold or/and a retention_time, and then flushes them out into the wild. Example: To aggregate sample by resource_metadata and keep the resource_metadata of the latest received sample; AggregatorTransformer(retention_time=60, resource_metadata='last') To aggregate sample by user_id and resource_metadata and keep the user_id of the first received sample and drop the resource_metadata. AggregatorTransformer(size=15, user_id='first', resource_metadata='drop') To keep the timestamp of the last received sample rather than the first: AggregatorTransformer(timestamp="last") """ def __init__(self, size=1, retention_time=None, project_id=None, user_id=None, resource_metadata="last", timestamp="first", **kwargs): super(AggregatorTransformer, self).__init__(**kwargs) self.samples = {} self.counts = collections.defaultdict(int) self.size = int(size) if size else None self.retention_time = float(retention_time) if retention_time else None if not (self.size or self.retention_time): self.size = 1 if timestamp in ["first", "last"]: self.timestamp = timestamp else: self.timestamp = "first" self.initial_timestamp = None self.aggregated_samples = 0 self.key_attributes = [] self.merged_attribute_policy = {} self._init_attribute('project_id', project_id) self._init_attribute('user_id', user_id) self._init_attribute('resource_metadata', resource_metadata, is_droppable=True, mandatory=True) def _init_attribute(self, name, value, is_droppable=False, mandatory=False): drop = ['drop'] if is_droppable else [] if value or mandatory: if value not in ['last', 'first'] + drop: LOG.warning('%s is unknown (%s), using last' % (name, value)) value = 'last' self.merged_attribute_policy[name] = value else: self.key_attributes.append(name) def _get_unique_key(self, s): # NOTE(arezmerita): in samples generated by ceilometer middleware, # when accessing without authentication publicly readable/writable # swift containers, the project_id and the user_id are missing. # They will be replaced by <undefined> for unique key construction. keys = ['<undefined>' if getattr(s, f) is None else getattr(s, f) for f in self.key_attributes] non_aggregated_keys = "-".join(keys) # NOTE(sileht): it assumes, a meter always have the same unit/type return "%s-%s-%s" % (s.name, s.resource_id, non_aggregated_keys)
[docs] def handle_sample(self, sample_): if not self.initial_timestamp: self.initial_timestamp = timeutils.parse_isotime(sample_.timestamp) self.aggregated_samples += 1 key = self._get_unique_key(sample_) self.counts[key] += 1 if key not in self.samples: self.samples[key] = self._convert(sample_) if self.merged_attribute_policy[ 'resource_metadata'] == 'drop': self.samples[key].resource_metadata = {} else: if self.timestamp == "last": self.samples[key].timestamp = sample_.timestamp if sample_.type == sample.TYPE_CUMULATIVE: self.samples[key].volume = self._scale(sample_) else: self.samples[key].volume += self._scale(sample_) for field in self.merged_attribute_policy: if self.merged_attribute_policy[field] == 'last': setattr(self.samples[key], field, getattr(sample_, field))
[docs] def flush(self): if not self.initial_timestamp: return [] expired = (self.retention_time and timeutils.is_older_than(self.initial_timestamp, self.retention_time)) full = self.size and self.aggregated_samples >= self.size if full or expired: x = list(self.samples.values()) # gauge aggregates need to be averages for s in x: if s.type == sample.TYPE_GAUGE: key = self._get_unique_key(s) s.volume /= self.counts[key] self.samples.clear() self.counts.clear() self.aggregated_samples = 0 self.initial_timestamp = None return x return []

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