Refactor logcontext resource usage tracking (#3501)

Factor out the resource usage tracking out to a separate object, which can be
passed around and copied independently of the logcontext itself.
This commit is contained in:
Richard van der Hoff 2018-07-10 13:56:07 +01:00 committed by GitHub
parent 16b10666e7
commit 55370331da
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5 changed files with 146 additions and 130 deletions

0
changelog.d/3501.misc Normal file
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@ -149,7 +149,9 @@ class RequestMetrics(object):
self.name = name
self.method = method
self._request_stats = _RequestStats.from_context(self.start_context)
# _request_stats records resource usage that we have already added
# to the "in flight" metrics.
self._request_stats = self.start_context.get_resource_usage()
_in_flight_requests.add(self)
@ -177,18 +179,22 @@ class RequestMetrics(object):
time_sec - self.start
)
ru_utime, ru_stime = context.get_resource_usage()
resource_usage = context.get_resource_usage()
response_ru_utime.labels(request.method, self.name, tag).inc(ru_utime)
response_ru_stime.labels(request.method, self.name, tag).inc(ru_stime)
response_ru_utime.labels(request.method, self.name, tag).inc(
resource_usage.ru_utime,
)
response_ru_stime.labels(request.method, self.name, tag).inc(
resource_usage.ru_stime,
)
response_db_txn_count.labels(request.method, self.name, tag).inc(
context.db_txn_count
resource_usage.db_txn_count
)
response_db_txn_duration.labels(request.method, self.name, tag).inc(
context.db_txn_duration_sec
resource_usage.db_txn_duration_sec
)
response_db_sched_duration.labels(request.method, self.name, tag).inc(
context.db_sched_duration_sec
resource_usage.db_sched_duration_sec
)
response_size.labels(request.method, self.name, tag).inc(request.sentLength)
@ -201,7 +207,10 @@ class RequestMetrics(object):
def update_metrics(self):
"""Updates the in flight metrics with values from this request.
"""
diff = self._request_stats.update(self.start_context)
new_stats = self.start_context.get_resource_usage()
diff = new_stats - self._request_stats
self._request_stats = new_stats
in_flight_requests_ru_utime.labels(self.method, self.name).inc(diff.ru_utime)
in_flight_requests_ru_stime.labels(self.method, self.name).inc(diff.ru_stime)
@ -217,61 +226,3 @@ class RequestMetrics(object):
in_flight_requests_db_sched_duration.labels(self.method, self.name).inc(
diff.db_sched_duration_sec
)
class _RequestStats(object):
"""Keeps tracks of various metrics for an in flight request.
"""
__slots__ = [
"ru_utime",
"ru_stime",
"db_txn_count",
"db_txn_duration_sec",
"db_sched_duration_sec",
]
def __init__(
self, ru_utime, ru_stime, db_txn_count, db_txn_duration_sec, db_sched_duration_sec
):
self.ru_utime = ru_utime
self.ru_stime = ru_stime
self.db_txn_count = db_txn_count
self.db_txn_duration_sec = db_txn_duration_sec
self.db_sched_duration_sec = db_sched_duration_sec
@staticmethod
def from_context(context):
ru_utime, ru_stime = context.get_resource_usage()
return _RequestStats(
ru_utime, ru_stime,
context.db_txn_count,
context.db_txn_duration_sec,
context.db_sched_duration_sec,
)
def update(self, context):
"""Updates the current values and returns the difference between the
old and new values.
Returns:
_RequestStats: The difference between the old and new values
"""
new = _RequestStats.from_context(context)
diff = _RequestStats(
new.ru_utime - self.ru_utime,
new.ru_stime - self.ru_stime,
new.db_txn_count - self.db_txn_count,
new.db_txn_duration_sec - self.db_txn_duration_sec,
new.db_sched_duration_sec - self.db_sched_duration_sec,
)
self.ru_utime = new.ru_utime
self.ru_stime = new.ru_stime
self.db_txn_count = new.db_txn_count
self.db_txn_duration_sec = new.db_txn_duration_sec
self.db_sched_duration_sec = new.db_sched_duration_sec
return diff

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@ -20,7 +20,7 @@ from twisted.web.server import Request, Site
from synapse.http import redact_uri
from synapse.http.request_metrics import RequestMetrics
from synapse.util.logcontext import LoggingContext
from synapse.util.logcontext import LoggingContext, ContextResourceUsage
logger = logging.getLogger(__name__)
@ -95,15 +95,9 @@ class SynapseRequest(Request):
def _finished_processing(self):
try:
context = LoggingContext.current_context()
ru_utime, ru_stime = context.get_resource_usage()
db_txn_count = context.db_txn_count
db_txn_duration_sec = context.db_txn_duration_sec
db_sched_duration_sec = context.db_sched_duration_sec
evt_db_fetch_count = context.evt_db_fetch_count
usage = context.get_resource_usage()
except Exception:
ru_utime, ru_stime = (0, 0)
db_txn_count, db_txn_duration_sec = (0, 0)
evt_db_fetch_count = 0
usage = ContextResourceUsage()
end_time = time.time()
@ -130,18 +124,18 @@ class SynapseRequest(Request):
self.site.site_tag,
authenticated_entity,
end_time - self.start_time,
ru_utime,
ru_stime,
db_sched_duration_sec,
db_txn_duration_sec,
int(db_txn_count),
usage.ru_utime,
usage.ru_stime,
usage.db_sched_duration_sec,
usage.db_txn_duration_sec,
int(usage.db_txn_count),
self.sentLength,
self.code,
self.method,
self.get_redacted_uri(),
self.clientproto,
user_agent,
evt_db_fetch_count,
usage.evt_db_fetch_count,
)
try:

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@ -49,6 +49,90 @@ except Exception:
return None
class ContextResourceUsage(object):
"""Object for tracking the resources used by a log context
Attributes:
ru_utime (float): user CPU time (in seconds)
ru_stime (float): system CPU time (in seconds)
db_txn_count (int): number of database transactions done
db_sched_duration_sec (float): amount of time spent waiting for a
database connection
db_txn_duration_sec (float): amount of time spent doing database
transactions (excluding scheduling time)
evt_db_fetch_count (int): number of events requested from the database
"""
__slots__ = [
"ru_stime", "ru_utime",
"db_txn_count", "db_txn_duration_sec", "db_sched_duration_sec",
"evt_db_fetch_count",
]
def __init__(self, copy_from=None):
"""Create a new ContextResourceUsage
Args:
copy_from (ContextResourceUsage|None): if not None, an object to
copy stats from
"""
if copy_from is None:
self.reset()
else:
self.ru_utime = copy_from.ru_utime
self.ru_stime = copy_from.ru_stime
self.db_txn_count = copy_from.db_txn_count
self.db_txn_duration_sec = copy_from.db_txn_duration_sec
self.db_sched_duration_sec = copy_from.db_sched_duration_sec
self.evt_db_fetch_count = copy_from.evt_db_fetch_count
def copy(self):
return ContextResourceUsage(copy_from=self)
def reset(self):
self.ru_stime = 0.
self.ru_utime = 0.
self.db_txn_count = 0
self.db_txn_duration_sec = 0
self.db_sched_duration_sec = 0
self.evt_db_fetch_count = 0
def __iadd__(self, other):
"""Add another ContextResourceUsage's stats to this one's.
Args:
other (ContextResourceUsage): the other resource usage object
"""
self.ru_utime += other.ru_utime
self.ru_stime += other.ru_stime
self.db_txn_count += other.db_txn_count
self.db_txn_duration_sec += other.db_txn_duration_sec
self.db_sched_duration_sec += other.db_sched_duration_sec
self.evt_db_fetch_count += other.evt_db_fetch_count
return self
def __isub__(self, other):
self.ru_utime -= other.ru_utime
self.ru_stime -= other.ru_stime
self.db_txn_count -= other.db_txn_count
self.db_txn_duration_sec -= other.db_txn_duration_sec
self.db_sched_duration_sec -= other.db_sched_duration_sec
self.evt_db_fetch_count -= other.evt_db_fetch_count
return self
def __add__(self, other):
res = ContextResourceUsage(copy_from=self)
res += other
return res
def __sub__(self, other):
res = ContextResourceUsage(copy_from=self)
res -= other
return res
class LoggingContext(object):
"""Additional context for log formatting. Contexts are scoped within a
"with" block.
@ -58,9 +142,8 @@ class LoggingContext(object):
"""
__slots__ = [
"previous_context", "name", "ru_stime", "ru_utime",
"db_txn_count", "db_txn_duration_sec", "db_sched_duration_sec",
"evt_db_fetch_count",
"previous_context", "name",
"_resource_usage",
"usage_start",
"main_thread", "alive",
"request", "tag",
@ -103,18 +186,9 @@ class LoggingContext(object):
def __init__(self, name=None):
self.previous_context = LoggingContext.current_context()
self.name = name
self.ru_stime = 0.
self.ru_utime = 0.
self.db_txn_count = 0
# sec spent waiting for db txns, excluding scheduling time
self.db_txn_duration_sec = 0
# sec spent waiting for db txns to be scheduled
self.db_sched_duration_sec = 0
# number of events this thread has fetched from the db
self.evt_db_fetch_count = 0
# track the resources used by this context so far
self._resource_usage = ContextResourceUsage()
# If alive has the thread resource usage when the logcontext last
# became active.
@ -207,39 +281,43 @@ class LoggingContext(object):
logger.warning("Stopped logcontext %s on different thread", self)
return
# When we stop, let's record the resource used since we started
if self.usage_start:
usage_end = get_thread_resource_usage()
# When we stop, let's record the cpu used since we started
if not self.usage_start:
logger.warning(
"Called stop on logcontext %s without calling start", self,
)
return
self.ru_utime += usage_end.ru_utime - self.usage_start.ru_utime
self.ru_stime += usage_end.ru_stime - self.usage_start.ru_stime
usage_end = get_thread_resource_usage()
self.usage_start = None
else:
logger.warning("Called stop on logcontext %s without calling start", self)
self._resource_usage.ru_utime += usage_end.ru_utime - self.usage_start.ru_utime
self._resource_usage.ru_stime += usage_end.ru_stime - self.usage_start.ru_stime
self.usage_start = None
def get_resource_usage(self):
"""Get CPU time used by this logcontext so far.
"""Get resources used by this logcontext so far.
Returns:
tuple[float, float]: The user and system CPU usage in seconds
ContextResourceUsage: a *copy* of the object tracking resource
usage so far
"""
ru_utime = self.ru_utime
ru_stime = self.ru_stime
# we always return a copy, for consistency
res = self._resource_usage.copy()
# If we are on the correct thread and we're currently running then we
# can include resource usage so far.
is_main_thread = threading.current_thread() is self.main_thread
if self.alive and self.usage_start and is_main_thread:
current = get_thread_resource_usage()
ru_utime += current.ru_utime - self.usage_start.ru_utime
ru_stime += current.ru_stime - self.usage_start.ru_stime
res.ru_utime += current.ru_utime - self.usage_start.ru_utime
res.ru_stime += current.ru_stime - self.usage_start.ru_stime
return ru_utime, ru_stime
return res
def add_database_transaction(self, duration_sec):
self.db_txn_count += 1
self.db_txn_duration_sec += duration_sec
self._resource_usage.db_txn_count += 1
self._resource_usage.db_txn_duration_sec += duration_sec
def add_database_scheduled(self, sched_sec):
"""Record a use of the database pool
@ -248,7 +326,7 @@ class LoggingContext(object):
sched_sec (float): number of seconds it took us to get a
connection
"""
self.db_sched_duration_sec += sched_sec
self._resource_usage.db_sched_duration_sec += sched_sec
def record_event_fetch(self, event_count):
"""Record a number of events being fetched from the db
@ -256,7 +334,7 @@ class LoggingContext(object):
Args:
event_count (int): number of events being fetched
"""
self.evt_db_fetch_count += event_count
self._resource_usage.evt_db_fetch_count += event_count
class LoggingContextFilter(logging.Filter):

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@ -60,10 +60,9 @@ def measure_func(name):
class Measure(object):
__slots__ = [
"clock", "name", "start_context", "start", "new_context", "ru_utime",
"ru_stime",
"db_txn_count", "db_txn_duration_sec", "db_sched_duration_sec",
"clock", "name", "start_context", "start",
"created_context",
"start_usage",
]
def __init__(self, clock, name):
@ -81,10 +80,7 @@ class Measure(object):
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_sec = self.start_context.db_txn_duration_sec
self.db_sched_duration_sec = self.start_context.db_sched_duration_sec
self.start_usage = self.start_context.get_resource_usage()
def __exit__(self, exc_type, exc_val, exc_tb):
if isinstance(exc_type, Exception) or not self.start_context:
@ -108,15 +104,12 @@ class Measure(object):
logger.warn("Expected context. (%r)", self.name)
return
ru_utime, ru_stime = context.get_resource_usage()
block_ru_utime.labels(self.name).inc(ru_utime - self.ru_utime)
block_ru_stime.labels(self.name).inc(ru_stime - self.ru_stime)
block_db_txn_count.labels(self.name).inc(context.db_txn_count - self.db_txn_count)
block_db_txn_duration.labels(self.name).inc(
context.db_txn_duration_sec - self.db_txn_duration_sec)
block_db_sched_duration.labels(self.name).inc(
context.db_sched_duration_sec - self.db_sched_duration_sec)
usage = context.get_resource_usage() - self.start_usage
block_ru_utime.labels(self.name).inc(usage.ru_utime)
block_ru_stime.labels(self.name).inc(usage.ru_stime)
block_db_txn_count.labels(self.name).inc(usage.db_txn_count)
block_db_txn_duration.labels(self.name).inc(usage.db_txn_duration_sec)
block_db_sched_duration.labels(self.name).inc(usage.db_sched_duration_sec)
if self.created_context:
self.start_context.__exit__(exc_type, exc_val, exc_tb)