anonymousland-synapse/synapse/util/metrics.py
Richard van der Hoff 3d12d97415 Track DB scheduling delay per-request
For each request, track the amount of time spent waiting for a db
connection. This entails adding it to the LoggingContext and we may as well add
metrics for it while we are passing.
2018-01-16 17:23:32 +00:00

167 lines
5.1 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 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.
from twisted.internet import defer
from synapse.util.logcontext import LoggingContext
import synapse.metrics
from functools import wraps
import logging
logger = logging.getLogger(__name__)
metrics = synapse.metrics.get_metrics_for(__name__)
# total number of times we have hit this block
response_count = metrics.register_counter(
"block_count",
labels=["block_name"],
alternative_names=(
# the following are all deprecated aliases for the same metric
metrics.name_prefix + x for x in (
"_block_timer:count",
"_block_ru_utime:count",
"_block_ru_stime:count",
"_block_db_txn_count:count",
"_block_db_txn_duration:count",
)
)
)
block_timer = metrics.register_counter(
"block_time_seconds",
labels=["block_name"],
alternative_names=(
metrics.name_prefix + "_block_timer:total",
),
)
block_ru_utime = metrics.register_counter(
"block_ru_utime_seconds", labels=["block_name"],
alternative_names=(
metrics.name_prefix + "_block_ru_utime:total",
),
)
block_ru_stime = metrics.register_counter(
"block_ru_stime_seconds", labels=["block_name"],
alternative_names=(
metrics.name_prefix + "_block_ru_stime:total",
),
)
block_db_txn_count = metrics.register_counter(
"block_db_txn_count", labels=["block_name"],
alternative_names=(
metrics.name_prefix + "_block_db_txn_count:total",
),
)
# seconds spent waiting for db txns, excluding scheduling time, in this block
block_db_txn_duration = metrics.register_counter(
"block_db_txn_duration_seconds", labels=["block_name"],
alternative_names=(
metrics.name_prefix + "_block_db_txn_count:total",
),
)
# seconds spent waiting for a db connection, in this block
block_db_sched_duration = metrics.register_counter(
"block_db_sched_duration_seconds", labels=["block_name"],
)
def measure_func(name):
def wrapper(func):
@wraps(func)
@defer.inlineCallbacks
def measured_func(self, *args, **kwargs):
with Measure(self.clock, name):
r = yield func(self, *args, **kwargs)
defer.returnValue(r)
return measured_func
return wrapper
class Measure(object):
__slots__ = [
"clock", "name", "start_context", "start", "new_context", "ru_utime",
"ru_stime",
"db_txn_count", "db_txn_duration_ms", "db_sched_duration_ms",
"created_context",
]
def __init__(self, clock, name):
self.clock = clock
self.name = name
self.start_context = None
self.start = None
self.created_context = False
def __enter__(self):
self.start = self.clock.time_msec()
self.start_context = LoggingContext.current_context()
if not self.start_context:
self.start_context = LoggingContext("Measure")
self.start_context.__enter__()
self.created_context = True
self.ru_utime, self.ru_stime = self.start_context.get_resource_usage()
self.db_txn_count = self.start_context.db_txn_count
self.db_txn_duration_ms = self.start_context.db_txn_duration_ms
self.db_sched_duration_ms = self.start_context.db_sched_duration_ms
def __exit__(self, exc_type, exc_val, exc_tb):
if isinstance(exc_type, Exception) or not self.start_context:
return
duration = self.clock.time_msec() - self.start
block_timer.inc_by(duration, self.name)
context = LoggingContext.current_context()
if context != self.start_context:
logger.warn(
"Context has unexpectedly changed from '%s' to '%s'. (%r)",
self.start_context, context, self.name
)
return
if not context:
logger.warn("Expected context. (%r)", self.name)
return
ru_utime, ru_stime = context.get_resource_usage()
block_ru_utime.inc_by(ru_utime - self.ru_utime, self.name)
block_ru_stime.inc_by(ru_stime - self.ru_stime, self.name)
block_db_txn_count.inc_by(
context.db_txn_count - self.db_txn_count, self.name
)
block_db_txn_duration.inc_by(
(context.db_txn_duration_ms - self.db_txn_duration_ms) / 1000.,
self.name
)
block_db_sched_duration.inc_by(
(context.db_sched_duration_ms - self.db_sched_duration_ms) / 1000.,
self.name
)
if self.created_context:
self.start_context.__exit__(exc_type, exc_val, exc_tb)