501 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			501 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Python
		
	
	
| # -*- coding: utf-8 -*-
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| # Copyright 2015, 2016 OpenMarket Ltd
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| #
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| # Licensed under the Apache License, Version 2.0 (the "License");
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| # you may not use this file except in compliance with the License.
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| # You may obtain a copy of the License at
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| #
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| #     http://www.apache.org/licenses/LICENSE-2.0
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| #
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| # Unless required by applicable law or agreed to in writing, software
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| # distributed under the License is distributed on an "AS IS" BASIS,
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| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| # See the License for the specific language governing permissions and
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| # limitations under the License.
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| 
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| import functools
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| import gc
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| import logging
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| import os
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| import platform
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| import threading
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| import time
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| from typing import Dict, Union
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| 
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| import six
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| 
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| import attr
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| from prometheus_client import Counter, Gauge, Histogram
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| from prometheus_client.core import REGISTRY, GaugeMetricFamily, HistogramMetricFamily
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| 
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| from twisted.internet import reactor
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| 
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| import synapse
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| from synapse.metrics._exposition import (
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|     MetricsResource,
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|     generate_latest,
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|     start_http_server,
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| )
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| from synapse.util.versionstring import get_version_string
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| 
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| logger = logging.getLogger(__name__)
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| 
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| METRICS_PREFIX = "/_synapse/metrics"
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| 
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| running_on_pypy = platform.python_implementation() == "PyPy"
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| all_gauges = {}  # type: Dict[str, Union[LaterGauge, InFlightGauge, BucketCollector]]
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| 
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| HAVE_PROC_SELF_STAT = os.path.exists("/proc/self/stat")
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| 
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| 
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| class RegistryProxy(object):
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|     @staticmethod
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|     def collect():
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|         for metric in REGISTRY.collect():
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|             if not metric.name.startswith("__"):
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|                 yield metric
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| 
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| 
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| @attr.s(hash=True)
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| class LaterGauge(object):
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| 
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|     name = attr.ib()
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|     desc = attr.ib()
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|     labels = attr.ib(hash=False)
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|     caller = attr.ib()
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| 
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|     def collect(self):
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| 
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|         g = GaugeMetricFamily(self.name, self.desc, labels=self.labels)
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| 
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|         try:
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|             calls = self.caller()
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|         except Exception:
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|             logger.exception("Exception running callback for LaterGauge(%s)", self.name)
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|             yield g
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|             return
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| 
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|         if isinstance(calls, dict):
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|             for k, v in six.iteritems(calls):
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|                 g.add_metric(k, v)
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|         else:
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|             g.add_metric([], calls)
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| 
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|         yield g
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| 
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|     def __attrs_post_init__(self):
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|         self._register()
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| 
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|     def _register(self):
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|         if self.name in all_gauges.keys():
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|             logger.warning("%s already registered, reregistering" % (self.name,))
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|             REGISTRY.unregister(all_gauges.pop(self.name))
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| 
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|         REGISTRY.register(self)
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|         all_gauges[self.name] = self
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| 
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| 
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| class InFlightGauge(object):
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|     """Tracks number of things (e.g. requests, Measure blocks, etc) in flight
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|     at any given time.
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| 
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|     Each InFlightGauge will create a metric called `<name>_total` that counts
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|     the number of in flight blocks, as well as a metrics for each item in the
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|     given `sub_metrics` as `<name>_<sub_metric>` which will get updated by the
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|     callbacks.
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| 
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|     Args:
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|         name (str)
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|         desc (str)
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|         labels (list[str])
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|         sub_metrics (list[str]): A list of sub metrics that the callbacks
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|             will update.
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|     """
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| 
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|     def __init__(self, name, desc, labels, sub_metrics):
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|         self.name = name
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|         self.desc = desc
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|         self.labels = labels
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|         self.sub_metrics = sub_metrics
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| 
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|         # Create a class which have the sub_metrics values as attributes, which
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|         # default to 0 on initialization. Used to pass to registered callbacks.
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|         self._metrics_class = attr.make_class(
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|             "_MetricsEntry", attrs={x: attr.ib(0) for x in sub_metrics}, slots=True
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|         )
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| 
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|         # Counts number of in flight blocks for a given set of label values
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|         self._registrations = {}  # type: Dict
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| 
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|         # Protects access to _registrations
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|         self._lock = threading.Lock()
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| 
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|         self._register_with_collector()
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| 
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|     def register(self, key, callback):
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|         """Registers that we've entered a new block with labels `key`.
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| 
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|         `callback` gets called each time the metrics are collected. The same
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|         value must also be given to `unregister`.
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| 
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|         `callback` gets called with an object that has an attribute per
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|         sub_metric, which should be updated with the necessary values. Note that
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|         the metrics object is shared between all callbacks registered with the
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|         same key.
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| 
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|         Note that `callback` may be called on a separate thread.
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|         """
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|         with self._lock:
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|             self._registrations.setdefault(key, set()).add(callback)
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| 
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|     def unregister(self, key, callback):
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|         """Registers that we've exited a block with labels `key`.
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|         """
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| 
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|         with self._lock:
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|             self._registrations.setdefault(key, set()).discard(callback)
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| 
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|     def collect(self):
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|         """Called by prometheus client when it reads metrics.
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| 
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|         Note: may be called by a separate thread.
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|         """
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|         in_flight = GaugeMetricFamily(
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|             self.name + "_total", self.desc, labels=self.labels
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|         )
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| 
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|         metrics_by_key = {}
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| 
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|         # We copy so that we don't mutate the list while iterating
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|         with self._lock:
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|             keys = list(self._registrations)
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| 
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|         for key in keys:
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|             with self._lock:
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|                 callbacks = set(self._registrations[key])
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| 
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|             in_flight.add_metric(key, len(callbacks))
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| 
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|             metrics = self._metrics_class()
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|             metrics_by_key[key] = metrics
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|             for callback in callbacks:
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|                 callback(metrics)
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| 
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|         yield in_flight
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| 
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|         for name in self.sub_metrics:
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|             gauge = GaugeMetricFamily(
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|                 "_".join([self.name, name]), "", labels=self.labels
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|             )
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|             for key, metrics in six.iteritems(metrics_by_key):
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|                 gauge.add_metric(key, getattr(metrics, name))
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|             yield gauge
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| 
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|     def _register_with_collector(self):
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|         if self.name in all_gauges.keys():
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|             logger.warning("%s already registered, reregistering" % (self.name,))
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|             REGISTRY.unregister(all_gauges.pop(self.name))
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| 
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|         REGISTRY.register(self)
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|         all_gauges[self.name] = self
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| 
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| 
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| @attr.s(hash=True)
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| class BucketCollector(object):
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|     """
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|     Like a Histogram, but allows buckets to be point-in-time instead of
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|     incrementally added to.
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| 
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|     Args:
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|         name (str): Base name of metric to be exported to Prometheus.
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|         data_collector (callable -> dict): A synchronous callable that
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|             returns a dict mapping bucket to number of items in the
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|             bucket. If these buckets are not the same as the buckets
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|             given to this class, they will be remapped into them.
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|         buckets (list[float]): List of floats/ints of the buckets to
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|             give to Prometheus. +Inf is ignored, if given.
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| 
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|     """
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| 
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|     name = attr.ib()
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|     data_collector = attr.ib()
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|     buckets = attr.ib()
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| 
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|     def collect(self):
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| 
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|         # Fetch the data -- this must be synchronous!
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|         data = self.data_collector()
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| 
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|         buckets = {}  # type: Dict[float, int]
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| 
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|         res = []
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|         for x in data.keys():
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|             for i, bound in enumerate(self.buckets):
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|                 if x <= bound:
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|                     buckets[bound] = buckets.get(bound, 0) + data[x]
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| 
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|         for i in self.buckets:
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|             res.append([str(i), buckets.get(i, 0)])
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| 
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|         res.append(["+Inf", sum(data.values())])
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| 
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|         metric = HistogramMetricFamily(
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|             self.name, "", buckets=res, sum_value=sum([x * y for x, y in data.items()])
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|         )
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|         yield metric
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| 
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|     def __attrs_post_init__(self):
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|         self.buckets = [float(x) for x in self.buckets if x != "+Inf"]
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|         if self.buckets != sorted(self.buckets):
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|             raise ValueError("Buckets not sorted")
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| 
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|         self.buckets = tuple(self.buckets)
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| 
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|         if self.name in all_gauges.keys():
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|             logger.warning("%s already registered, reregistering" % (self.name,))
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|             REGISTRY.unregister(all_gauges.pop(self.name))
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| 
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|         REGISTRY.register(self)
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|         all_gauges[self.name] = self
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| 
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| 
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| #
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| # Detailed CPU metrics
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| #
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| 
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| 
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| class CPUMetrics(object):
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|     def __init__(self):
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|         ticks_per_sec = 100
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|         try:
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|             # Try and get the system config
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|             ticks_per_sec = os.sysconf("SC_CLK_TCK")
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|         except (ValueError, TypeError, AttributeError):
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|             pass
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| 
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|         self.ticks_per_sec = ticks_per_sec
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| 
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|     def collect(self):
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|         if not HAVE_PROC_SELF_STAT:
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|             return
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| 
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|         with open("/proc/self/stat") as s:
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|             line = s.read()
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|             raw_stats = line.split(") ", 1)[1].split(" ")
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| 
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|             user = GaugeMetricFamily("process_cpu_user_seconds_total", "")
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|             user.add_metric([], float(raw_stats[11]) / self.ticks_per_sec)
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|             yield user
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| 
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|             sys = GaugeMetricFamily("process_cpu_system_seconds_total", "")
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|             sys.add_metric([], float(raw_stats[12]) / self.ticks_per_sec)
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|             yield sys
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| 
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| 
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| REGISTRY.register(CPUMetrics())
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| 
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| #
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| # Python GC metrics
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| #
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| 
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| gc_unreachable = Gauge("python_gc_unreachable_total", "Unreachable GC objects", ["gen"])
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| gc_time = Histogram(
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|     "python_gc_time",
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|     "Time taken to GC (sec)",
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|     ["gen"],
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|     buckets=[
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|         0.0025,
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|         0.005,
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|         0.01,
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|         0.025,
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|         0.05,
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|         0.10,
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|         0.25,
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|         0.50,
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|         1.00,
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|         2.50,
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|         5.00,
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|         7.50,
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|         15.00,
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|         30.00,
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|         45.00,
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|         60.00,
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|     ],
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| )
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| 
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| 
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| class GCCounts(object):
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|     def collect(self):
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|         cm = GaugeMetricFamily("python_gc_counts", "GC object counts", labels=["gen"])
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|         for n, m in enumerate(gc.get_count()):
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|             cm.add_metric([str(n)], m)
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| 
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|         yield cm
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| 
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| 
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| if not running_on_pypy:
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|     REGISTRY.register(GCCounts())
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| 
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| #
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| # Twisted reactor metrics
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| #
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| 
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| tick_time = Histogram(
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|     "python_twisted_reactor_tick_time",
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|     "Tick time of the Twisted reactor (sec)",
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|     buckets=[0.001, 0.002, 0.005, 0.01, 0.025, 0.05, 0.1, 0.2, 0.5, 1, 2, 5],
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| )
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| pending_calls_metric = Histogram(
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|     "python_twisted_reactor_pending_calls",
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|     "Pending calls",
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|     buckets=[1, 2, 5, 10, 25, 50, 100, 250, 500, 1000],
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| )
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| 
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| #
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| # Federation Metrics
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| #
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| 
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| sent_transactions_counter = Counter("synapse_federation_client_sent_transactions", "")
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| 
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| events_processed_counter = Counter("synapse_federation_client_events_processed", "")
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| 
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| event_processing_loop_counter = Counter(
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|     "synapse_event_processing_loop_count", "Event processing loop iterations", ["name"]
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| )
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| 
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| event_processing_loop_room_count = Counter(
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|     "synapse_event_processing_loop_room_count",
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|     "Rooms seen per event processing loop iteration",
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|     ["name"],
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| )
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| 
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| 
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| # Used to track where various components have processed in the event stream,
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| # e.g. federation sending, appservice sending, etc.
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| event_processing_positions = Gauge("synapse_event_processing_positions", "", ["name"])
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| 
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| # Used to track the current max events stream position
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| event_persisted_position = Gauge("synapse_event_persisted_position", "")
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| 
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| # Used to track the received_ts of the last event processed by various
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| # components
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| event_processing_last_ts = Gauge("synapse_event_processing_last_ts", "", ["name"])
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| 
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| # Used to track the lag processing events. This is the time difference
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| # between the last processed event's received_ts and the time it was
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| # finished being processed.
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| event_processing_lag = Gauge("synapse_event_processing_lag", "", ["name"])
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| 
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| # Build info of the running server.
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| build_info = Gauge(
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|     "synapse_build_info", "Build information", ["pythonversion", "version", "osversion"]
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| )
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| build_info.labels(
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|     " ".join([platform.python_implementation(), platform.python_version()]),
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|     get_version_string(synapse),
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|     " ".join([platform.system(), platform.release()]),
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| ).set(1)
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| 
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| last_ticked = time.time()
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| 
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| 
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| class ReactorLastSeenMetric(object):
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|     def collect(self):
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|         cm = GaugeMetricFamily(
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|             "python_twisted_reactor_last_seen",
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|             "Seconds since the Twisted reactor was last seen",
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|         )
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|         cm.add_metric([], time.time() - last_ticked)
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|         yield cm
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| 
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| 
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| REGISTRY.register(ReactorLastSeenMetric())
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| 
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| 
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| def runUntilCurrentTimer(func):
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|     @functools.wraps(func)
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|     def f(*args, **kwargs):
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|         now = reactor.seconds()
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|         num_pending = 0
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| 
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|         # _newTimedCalls is one long list of *all* pending calls. Below loop
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|         # is based off of impl of reactor.runUntilCurrent
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|         for delayed_call in reactor._newTimedCalls:
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|             if delayed_call.time > now:
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|                 break
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| 
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|             if delayed_call.delayed_time > 0:
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|                 continue
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| 
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|             num_pending += 1
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| 
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|         num_pending += len(reactor.threadCallQueue)
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|         start = time.time()
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|         ret = func(*args, **kwargs)
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|         end = time.time()
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| 
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|         # record the amount of wallclock time spent running pending calls.
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|         # This is a proxy for the actual amount of time between reactor polls,
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|         # since about 25% of time is actually spent running things triggered by
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|         # I/O events, but that is harder to capture without rewriting half the
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|         # reactor.
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|         tick_time.observe(end - start)
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|         pending_calls_metric.observe(num_pending)
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| 
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|         # Update the time we last ticked, for the metric to test whether
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|         # Synapse's reactor has frozen
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|         global last_ticked
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|         last_ticked = end
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| 
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|         if running_on_pypy:
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|             return ret
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| 
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|         # Check if we need to do a manual GC (since its been disabled), and do
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|         # one if necessary.
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|         threshold = gc.get_threshold()
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|         counts = gc.get_count()
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|         for i in (2, 1, 0):
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|             if threshold[i] < counts[i]:
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|                 if i == 0:
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|                     logger.debug("Collecting gc %d", i)
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|                 else:
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|                     logger.info("Collecting gc %d", i)
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| 
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|                 start = time.time()
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|                 unreachable = gc.collect(i)
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|                 end = time.time()
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| 
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|                 gc_time.labels(i).observe(end - start)
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|                 gc_unreachable.labels(i).set(unreachable)
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| 
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|         return ret
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| 
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|     return f
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| 
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| 
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| try:
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|     # Ensure the reactor has all the attributes we expect
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|     reactor.runUntilCurrent
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|     reactor._newTimedCalls
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|     reactor.threadCallQueue
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| 
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|     # runUntilCurrent is called when we have pending calls. It is called once
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|     # per iteratation after fd polling.
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|     reactor.runUntilCurrent = runUntilCurrentTimer(reactor.runUntilCurrent)
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| 
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|     # We manually run the GC each reactor tick so that we can get some metrics
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|     # about time spent doing GC,
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|     if not running_on_pypy:
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|         gc.disable()
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| except AttributeError:
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|     pass
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| 
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| __all__ = [
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|     "MetricsResource",
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|     "generate_latest",
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|     "start_http_server",
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|     "LaterGauge",
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|     "InFlightGauge",
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|     "BucketCollector",
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| ]
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