forked-synapse/synapse/metrics/__init__.py
Erik Johnston 73c7112433 Change CacheMetrics to be quicker
We change it so that each cache has an individual CacheMetric, instead
of having one global CacheMetric. This means that when a cache tries to
increment a counter it does not need to go through so many indirections.
2016-06-03 11:26:52 +01:00

197 lines
5.3 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2015, 2016 OpenMarket Ltd
#
# 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.
# Because otherwise 'resource' collides with synapse.metrics.resource
from __future__ import absolute_import
import logging
from resource import getrusage, RUSAGE_SELF
import functools
import os
import stat
import time
from twisted.internet import reactor
from .metric import (
CounterMetric, CallbackMetric, DistributionMetric, CacheMetric
)
logger = logging.getLogger(__name__)
all_metrics = []
class Metrics(object):
""" A single Metrics object gives a (mutable) slice view of the all_metrics
dict, allowing callers to easily register new metrics that are namespaced
nicely."""
def __init__(self, name):
self.name_prefix = name
def _register(self, metric_class, name, *args, **kwargs):
full_name = "%s_%s" % (self.name_prefix, name)
metric = metric_class(full_name, *args, **kwargs)
all_metrics.append(metric)
return metric
def register_counter(self, *args, **kwargs):
return self._register(CounterMetric, *args, **kwargs)
def register_callback(self, *args, **kwargs):
return self._register(CallbackMetric, *args, **kwargs)
def register_distribution(self, *args, **kwargs):
return self._register(DistributionMetric, *args, **kwargs)
def register_cache(self, *args, **kwargs):
return self._register(CacheMetric, *args, **kwargs)
def get_metrics_for(pkg_name):
""" Returns a Metrics instance for conveniently creating metrics
namespaced with the given name prefix. """
# Convert a "package.name" to "package_name" because Prometheus doesn't
# let us use . in metric names
return Metrics(pkg_name.replace(".", "_"))
def render_all():
strs = []
# TODO(paul): Internal hack
update_resource_metrics()
for metric in all_metrics:
try:
strs += metric.render()
except Exception:
strs += ["# FAILED to render"]
logger.exception("Failed to render metric")
strs.append("") # to generate a final CRLF
return "\n".join(strs)
# Now register some standard process-wide state metrics, to give indications of
# process resource usage
rusage = None
def update_resource_metrics():
global rusage
rusage = getrusage(RUSAGE_SELF)
resource_metrics = get_metrics_for("process.resource")
# msecs
resource_metrics.register_callback("utime", lambda: rusage.ru_utime * 1000)
resource_metrics.register_callback("stime", lambda: rusage.ru_stime * 1000)
# kilobytes
resource_metrics.register_callback("maxrss", lambda: rusage.ru_maxrss * 1024)
TYPES = {
stat.S_IFSOCK: "SOCK",
stat.S_IFLNK: "LNK",
stat.S_IFREG: "REG",
stat.S_IFBLK: "BLK",
stat.S_IFDIR: "DIR",
stat.S_IFCHR: "CHR",
stat.S_IFIFO: "FIFO",
}
def _process_fds():
counts = {(k,): 0 for k in TYPES.values()}
counts[("other",)] = 0
# Not every OS will have a /proc/self/fd directory
if not os.path.exists("/proc/self/fd"):
return counts
for fd in os.listdir("/proc/self/fd"):
try:
s = os.stat("/proc/self/fd/%s" % (fd))
fmt = stat.S_IFMT(s.st_mode)
if fmt in TYPES:
t = TYPES[fmt]
else:
t = "other"
counts[(t,)] += 1
except OSError:
# the dirh itself used by listdir() is usually missing by now
pass
return counts
get_metrics_for("process").register_callback("fds", _process_fds, labels=["type"])
reactor_metrics = get_metrics_for("reactor")
tick_time = reactor_metrics.register_distribution("tick_time")
pending_calls_metric = reactor_metrics.register_distribution("pending_calls")
def runUntilCurrentTimer(func):
@functools.wraps(func)
def f(*args, **kwargs):
now = reactor.seconds()
num_pending = 0
# _newTimedCalls is one long list of *all* pending calls. Below loop
# is based off of impl of reactor.runUntilCurrent
for delayed_call in reactor._newTimedCalls:
if delayed_call.time > now:
break
if delayed_call.delayed_time > 0:
continue
num_pending += 1
num_pending += len(reactor.threadCallQueue)
start = time.time() * 1000
ret = func(*args, **kwargs)
end = time.time() * 1000
tick_time.inc_by(end - start)
pending_calls_metric.inc_by(num_pending)
return ret
return f
try:
# Ensure the reactor has all the attributes we expect
reactor.runUntilCurrent
reactor._newTimedCalls
reactor.threadCallQueue
# runUntilCurrent is called when we have pending calls. It is called once
# per iteratation after fd polling.
reactor.runUntilCurrent = runUntilCurrentTimer(reactor.runUntilCurrent)
except AttributeError:
pass