Source code for apache_beam.metrics.metric

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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, 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')
[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))
[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 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