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# 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
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# http://www.apache.org/licenses/LICENSE-2.0
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# distributed under the License is distributed on an "AS IS" BASIS,
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"""
User-facing classes for Metrics API.
The classes in this file allow users to define and use metrics to be collected
and displayed as part of their pipeline execution.
- Metrics - This class lets pipeline and transform writers create and access
metric objects such as counters, distributions, etc.
"""
import inspect
from apache_beam.metrics.execution import MetricsEnvironment
from apache_beam.metrics.metricbase import Counter
from apache_beam.metrics.metricbase import Distribution
from apache_beam.metrics.metricbase import MetricName
__all__ = ['Metrics', 'MetricsFilter']
[docs]class Metrics(object):
"""Lets users create/access metric objects during pipeline execution."""
@staticmethod
[docs] def get_namespace(namespace):
if inspect.isclass(namespace):
return '{}.{}'.format(namespace.__module__, namespace.__name__)
elif isinstance(namespace, str):
return namespace
else:
raise ValueError('Unknown namespace type')
@staticmethod
[docs] def counter(namespace, name):
"""Obtains or creates a Counter metric.
Args:
namespace: A class or string that gives the namespace to a metric
name: A string that gives a unique name to a metric
Returns:
A Counter object.
"""
namespace = Metrics.get_namespace(namespace)
return Metrics.DelegatingCounter(MetricName(namespace, name))
@staticmethod
[docs] def distribution(namespace, name):
"""Obtains or creates a Distribution metric.
Distribution metrics are restricted to integer-only distributions.
Args:
namespace: A class or string that gives the namespace to a metric
name: A string that gives a unique name to a metric
Returns:
A Distribution object.
"""
namespace = Metrics.get_namespace(namespace)
return Metrics.DelegatingDistribution(MetricName(namespace, name))
[docs] class DelegatingCounter(Counter):
def __init__(self, metric_name):
self.metric_name = metric_name
[docs] def inc(self, n=1):
container = MetricsEnvironment.current_container()
if container is not None:
container.get_counter(self.metric_name).inc(n)
[docs] class DelegatingDistribution(Distribution):
def __init__(self, metric_name):
self.metric_name = metric_name
[docs] def update(self, value):
container = MetricsEnvironment.current_container()
if container is not None:
container.get_distribution(self.metric_name).update(value)
class MetricResults(object):
@staticmethod
def _matches_name(filter, metric_key):
if not filter.names and not filter.namespaces:
return True
if ((filter.namespaces and
metric_key.metric.namespace in filter.namespaces) or
(filter.names and
metric_key.metric.name in filter.names)):
return True
return False
@staticmethod
def _matches_sub_path(actual_scope, filter_scope):
start_pos = actual_scope.find(filter_scope)
end_pos = start_pos + len(filter_scope)
if start_pos == -1:
return False # No match at all
elif start_pos != 0 and actual_scope[start_pos - 1] != '/':
return False # The first entry was not exactly matched
elif end_pos != len(actual_scope) and actual_scope[end_pos] != '/':
return False # The last entry was not exactly matched
return True
@staticmethod
def _matches_scope(filter, metric_key):
if not filter.steps:
return True
for step in filter.steps:
if MetricResults._matches_sub_path(metric_key.step, step):
return True
return False
@staticmethod
def matches(filter, metric_key):
if filter is None:
return True
if (MetricResults._matches_name(filter, metric_key) and
MetricResults._matches_scope(filter, metric_key)):
return True
return False
def query(self, filter=None):
raise NotImplementedError
[docs]class MetricsFilter(object):
"""Simple object to filter metrics results.
This class is experimental. No backwards-compatibility guarantees.
If filters by matching a result's step-namespace-name with three internal
sets. No execution/matching logic is added to this object, so that it may
be used to construct arguments as an RPC request. It is left for runners
to implement matching logic by themselves.
"""
def __init__(self):
self._names = set()
self._namespaces = set()
self._steps = set()
@property
def steps(self):
return frozenset(self._steps)
@property
def names(self):
return frozenset(self._names)
@property
def namespaces(self):
return frozenset(self._namespaces)
[docs] def with_name(self, name):
return self.with_names([name])
[docs] def with_names(self, names):
if isinstance(names, str):
raise ValueError('Names must be a collection, not a string')
self._names.update(names)
return self
[docs] def with_namespace(self, namespace):
return self.with_namespaces([namespace])
[docs] def with_namespaces(self, namespaces):
if isinstance(namespaces, str):
raise ValueError('Namespaces must be an iterable, not a string')
self._namespaces.update([Metrics.get_namespace(ns) for ns in namespaces])
return self
[docs] def with_step(self, step):
return self.with_steps([step])
[docs] def with_steps(self, steps):
if isinstance(steps, str):
raise ValueError('Steps must be an iterable, not a string')
self._steps.update(steps)
return self