#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.
#
"""
This file contains metric cell classes. A metric cell is used to accumulate
in-memory changes to a metric. It represents a specific metric in a single
context.
"""
# pytype: skip-file
from __future__ import absolute_import
from __future__ import division
import threading
import time
from builtins import object
from typing import Optional
try:
import cython
except ImportError:
class fake_cython:
compiled = False
globals()['cython'] = fake_cython
__all__ = ['DistributionResult', 'GaugeResult']
class MetricCell(object):
"""For internal use only; no backwards-compatibility guarantees.
Accumulates in-memory changes to a metric.
A MetricCell represents a specific metric in a single context and bundle.
All subclasses must be thread safe, as these are used in the pipeline runners,
and may be subject to parallel/concurrent updates. Cells should only be used
directly within a runner.
"""
def __init__(self):
self._lock = threading.Lock()
def update(self, value):
raise NotImplementedError
def get_cumulative(self):
raise NotImplementedError
def __reduce__(self):
raise NotImplementedError
class CounterCell(MetricCell):
"""For internal use only; no backwards-compatibility guarantees.
Tracks the current value and delta of a counter metric.
Each cell tracks the state of a metric independently per context per bundle.
Therefore, each metric has a different cell in each bundle, cells are
aggregated by the runner.
This class is thread safe.
"""
def __init__(self, *args):
super(CounterCell, self).__init__(*args)
self.value = CounterAggregator.identity_element()
def reset(self):
self.value = CounterAggregator.identity_element()
def combine(self, other):
# type: (CounterCell) -> CounterCell
result = CounterCell()
result.inc(self.value + other.value)
return result
def inc(self, n=1):
self.update(n)
def dec(self, n=1):
self.update(-n)
def update(self, value):
if cython.compiled:
ivalue = value
# We hold the GIL, no need for another lock.
self.value += ivalue
else:
with self._lock:
self.value += value
def get_cumulative(self):
# type: () -> int
with self._lock:
return self.value
def to_runner_api_monitoring_info(self, name, transform_id):
from apache_beam.metrics import monitoring_infos
return monitoring_infos.int64_user_counter(
name.namespace,
name.name,
self.get_cumulative(),
ptransform=transform_id)
class DistributionCell(MetricCell):
"""For internal use only; no backwards-compatibility guarantees.
Tracks the current value and delta for a distribution metric.
Each cell tracks the state of a metric independently per context per bundle.
Therefore, each metric has a different cell in each bundle, that is later
aggregated.
This class is thread safe.
"""
def __init__(self, *args):
super(DistributionCell, self).__init__(*args)
self.data = DistributionAggregator.identity_element()
def reset(self):
self.data = DistributionAggregator.identity_element()
def combine(self, other):
# type: (DistributionCell) -> DistributionCell
result = DistributionCell()
result.data = self.data.combine(other.data)
return result
def update(self, value):
if cython.compiled:
# We will hold the GIL throughout the entire _update.
self._update(value)
else:
with self._lock:
self._update(value)
def _update(self, value):
if cython.compiled:
ivalue = value
else:
ivalue = int(value)
self.data.count = self.data.count + 1
self.data.sum = self.data.sum + ivalue
if ivalue < self.data.min:
self.data.min = ivalue
if ivalue > self.data.max:
self.data.max = ivalue
def get_cumulative(self):
# type: () -> DistributionData
with self._lock:
return self.data.get_cumulative()
def to_runner_api_monitoring_info(self, name, transform_id):
from apache_beam.metrics import monitoring_infos
return monitoring_infos.int64_user_distribution(
name.namespace,
name.name,
self.get_cumulative(),
ptransform=transform_id)
class GaugeCell(MetricCell):
"""For internal use only; no backwards-compatibility guarantees.
Tracks the current value and delta for a gauge metric.
Each cell tracks the state of a metric independently per context per bundle.
Therefore, each metric has a different cell in each bundle, that is later
aggregated.
This class is thread safe.
"""
def __init__(self, *args):
super(GaugeCell, self).__init__(*args)
self.data = GaugeAggregator.identity_element()
def reset(self):
self.data = GaugeAggregator.identity_element()
def combine(self, other):
# type: (GaugeCell) -> GaugeCell
result = GaugeCell()
result.data = self.data.combine(other.data)
return result
def set(self, value):
self.update(value)
def update(self, value):
value = int(value)
with self._lock:
# Set the value directly without checking timestamp, because
# this value is naturally the latest value.
self.data.value = value
self.data.timestamp = time.time()
def get_cumulative(self):
# type: () -> GaugeData
with self._lock:
return self.data.get_cumulative()
def to_runner_api_monitoring_info(self, name, transform_id):
from apache_beam.metrics import monitoring_infos
return monitoring_infos.int64_user_gauge(
name.namespace,
name.name,
self.get_cumulative(),
ptransform=transform_id)
[docs]class DistributionResult(object):
"""The result of a Distribution metric."""
def __init__(self, data):
# type: (DistributionData) -> None
self.data = data
def __eq__(self, other):
if isinstance(other, DistributionResult):
return self.data == other.data
else:
return False
def __hash__(self):
return hash(self.data)
def __ne__(self, other):
# TODO(BEAM-5949): Needed for Python 2 compatibility.
return not self == other
def __repr__(self):
return 'DistributionResult(sum={}, count={}, min={}, max={})'.format(
self.sum, self.count, self.min, self.max)
@property
def max(self):
return self.data.max if self.data.count else None
@property
def min(self):
return self.data.min if self.data.count else None
@property
def count(self):
return self.data.count
@property
def sum(self):
return self.data.sum
@property
def mean(self):
"""Returns the float mean of the distribution.
If the distribution contains no elements, it returns None.
"""
if self.data.count == 0:
return None
return self.data.sum / self.data.count
[docs]class GaugeResult(object):
def __init__(self, data):
# type: (GaugeData) -> None
self.data = data
def __eq__(self, other):
if isinstance(other, GaugeResult):
return self.data == other.data
else:
return False
def __hash__(self):
return hash(self.data)
def __ne__(self, other):
# TODO(BEAM-5949): Needed for Python 2 compatibility.
return not self == other
def __repr__(self):
return '<GaugeResult(value={}, timestamp={})>'.format(
self.value, self.timestamp)
@property
def value(self):
return self.data.value
@property
def timestamp(self):
return self.data.timestamp
class GaugeData(object):
"""For internal use only; no backwards-compatibility guarantees.
The data structure that holds data about a gauge metric.
Gauge metrics are restricted to integers only.
This object is not thread safe, so it's not supposed to be modified
by other than the GaugeCell that contains it.
"""
def __init__(self, value, timestamp=None):
self.value = value
self.timestamp = timestamp if timestamp is not None else 0
def __eq__(self, other):
return self.value == other.value and self.timestamp == other.timestamp
def __hash__(self):
return hash((self.value, self.timestamp))
def __ne__(self, other):
# TODO(BEAM-5949): Needed for Python 2 compatibility.
return not self == other
def __repr__(self):
return '<GaugeData(value={}, timestamp={})>'.format(
self.value, self.timestamp)
def get_cumulative(self):
# type: () -> GaugeData
return GaugeData(self.value, timestamp=self.timestamp)
def combine(self, other):
# type: (Optional[GaugeData]) -> GaugeData
if other is None:
return self
if other.timestamp > self.timestamp:
return other
else:
return self
@staticmethod
def singleton(value, timestamp=None):
# type: (...) -> GaugeData
return GaugeData(value, timestamp=timestamp)
class DistributionData(object):
"""For internal use only; no backwards-compatibility guarantees.
The data structure that holds data about a distribution metric.
Distribution metrics are restricted to distributions of integers only.
This object is not thread safe, so it's not supposed to be modified
by other than the DistributionCell that contains it.
"""
def __init__(self, sum, count, min, max):
if count:
self.sum = sum
self.count = count
self.min = min
self.max = max
else:
self.sum = self.count = 0
self.min = 2**63 - 1
# Avoid Wimplicitly-unsigned-literal caused by -2**63.
self.max = -self.min - 1
def __eq__(self, other):
return (
self.sum == other.sum and self.count == other.count and
self.min == other.min and self.max == other.max)
def __hash__(self):
return hash((self.sum, self.count, self.min, self.max))
def __ne__(self, other):
# TODO(BEAM-5949): Needed for Python 2 compatibility.
return not self == other
def __repr__(self):
return 'DistributionData(sum={}, count={}, min={}, max={})'.format(
self.sum, self.count, self.min, self.max)
def get_cumulative(self):
# type: () -> DistributionData
return DistributionData(self.sum, self.count, self.min, self.max)
def combine(self, other):
# type: (Optional[DistributionData]) -> DistributionData
if other is None:
return self
return DistributionData(
self.sum + other.sum,
self.count + other.count,
self.min if self.min < other.min else other.min,
self.max if self.max > other.max else other.max)
@staticmethod
def singleton(value):
return DistributionData(value, 1, value, value)
class MetricAggregator(object):
"""For internal use only; no backwards-compatibility guarantees.
Base interface for aggregating metric data during pipeline execution."""
def identity_element(self):
"""Returns the identical element of an Aggregation.
For the identity element, it must hold that
Aggregator.combine(any_element, identity_element) == any_element.
"""
raise NotImplementedError
def combine(self, x, y):
raise NotImplementedError
def result(self, x):
raise NotImplementedError
class CounterAggregator(MetricAggregator):
"""For internal use only; no backwards-compatibility guarantees.
Aggregator for Counter metric data during pipeline execution.
Values aggregated should be ``int`` objects.
"""
@staticmethod
def identity_element():
# type: () -> int
return 0
def combine(self, x, y):
# type: (...) -> int
return int(x) + int(y)
def result(self, x):
# type: (...) -> int
return int(x)
class DistributionAggregator(MetricAggregator):
"""For internal use only; no backwards-compatibility guarantees.
Aggregator for Distribution metric data during pipeline execution.
Values aggregated should be ``DistributionData`` objects.
"""
@staticmethod
def identity_element():
# type: () -> DistributionData
return DistributionData(0, 0, 2**63 - 1, -2**63)
def combine(self, x, y):
# type: (DistributionData, DistributionData) -> DistributionData
return x.combine(y)
def result(self, x):
# type: (DistributionData) -> DistributionResult
return DistributionResult(x.get_cumulative())
class GaugeAggregator(MetricAggregator):
"""For internal use only; no backwards-compatibility guarantees.
Aggregator for Gauge metric data during pipeline execution.
Values aggregated should be ``GaugeData`` objects.
"""
@staticmethod
def identity_element():
# type: () -> GaugeData
return GaugeData(None, timestamp=0)
def combine(self, x, y):
# type: (GaugeData, GaugeData) -> GaugeData
result = x.combine(y)
return result
def result(self, x):
# type: (GaugeData) -> GaugeResult
return GaugeResult(x.get_cumulative())