Attempt to include db threads in cpu usage stats (#3496)

Let's try to include time spent in the DB threads in the per-request/block cpu
usage metrics.
This commit is contained in:
Richard van der Hoff 2018-07-10 16:12:36 +01:00 committed by GitHub
parent 55370331da
commit c3c29aa196
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4 changed files with 39 additions and 20 deletions

1
changelog.d/3496.feature Normal file
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@ -0,0 +1 @@
Include CPU time from database threads in request/block metrics.

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@ -220,7 +220,7 @@ class SQLBaseStore(object):
self._clock.looping_call(loop, 10000)
def _new_transaction(self, conn, desc, after_callbacks, exception_callbacks,
logging_context, func, *args, **kwargs):
func, *args, **kwargs):
start = time.time()
txn_id = self._TXN_ID
@ -284,8 +284,7 @@ class SQLBaseStore(object):
end = time.time()
duration = end - start
if logging_context is not None:
logging_context.add_database_transaction(duration)
LoggingContext.current_context().add_database_transaction(duration)
transaction_logger.debug("[TXN END] {%s} %f sec", name, duration)
@ -309,19 +308,15 @@ class SQLBaseStore(object):
Returns:
Deferred: The result of func
"""
current_context = LoggingContext.current_context()
after_callbacks = []
exception_callbacks = []
def inner_func(conn, *args, **kwargs):
return self._new_transaction(
conn, desc, after_callbacks, exception_callbacks, current_context,
func, *args, **kwargs
)
try:
result = yield self.runWithConnection(inner_func, *args, **kwargs)
result = yield self.runWithConnection(
self._new_transaction,
desc, after_callbacks, exception_callbacks, func,
*args, **kwargs
)
for after_callback, after_args, after_kwargs in after_callbacks:
after_callback(*after_args, **after_kwargs)
@ -346,22 +341,25 @@ class SQLBaseStore(object):
Returns:
Deferred: The result of func
"""
current_context = LoggingContext.current_context()
parent_context = LoggingContext.current_context()
if parent_context == LoggingContext.sentinel:
logger.warn(
"Running db txn from sentinel context: metrics will be lost",
)
parent_context = None
start_time = time.time()
def inner_func(conn, *args, **kwargs):
with LoggingContext("runWithConnection") as context:
with LoggingContext("runWithConnection", parent_context) as context:
sched_duration_sec = time.time() - start_time
sql_scheduling_timer.observe(sched_duration_sec)
current_context.add_database_scheduled(sched_duration_sec)
context.add_database_scheduled(sched_duration_sec)
if self.database_engine.is_connection_closed(conn):
logger.debug("Reconnecting closed database connection")
conn.reconnect()
current_context.copy_to(context)
return func(conn, *args, **kwargs)
with PreserveLoggingContext():

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@ -261,7 +261,8 @@ class EventsWorkerStore(SQLBaseStore):
]
rows = self._new_transaction(
conn, "do_fetch", [], [], None, self._fetch_event_rows, event_ids
conn, "do_fetch", [], [],
self._fetch_event_rows, event_ids,
)
row_dict = {

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@ -137,12 +137,18 @@ class LoggingContext(object):
"""Additional context for log formatting. Contexts are scoped within a
"with" block.
If a parent is given when creating a new context, then:
- logging fields are copied from the parent to the new context on entry
- when the new context exits, the cpu usage stats are copied from the
child to the parent
Args:
name (str): Name for the context for debugging.
parent_context (LoggingContext|None): The parent of the new context
"""
__slots__ = [
"previous_context", "name",
"previous_context", "name", "parent_context",
"_resource_usage",
"usage_start",
"main_thread", "alive",
@ -183,7 +189,7 @@ class LoggingContext(object):
sentinel = Sentinel()
def __init__(self, name=None):
def __init__(self, name=None, parent_context=None):
self.previous_context = LoggingContext.current_context()
self.name = name
@ -199,6 +205,8 @@ class LoggingContext(object):
self.tag = ""
self.alive = True
self.parent_context = parent_context
def __str__(self):
return "%s@%x" % (self.name, id(self))
@ -236,6 +244,10 @@ class LoggingContext(object):
self.previous_context, old_context
)
self.alive = True
if self.parent_context is not None:
self.parent_context.copy_to(self)
return self
def __exit__(self, type, value, traceback):
@ -257,6 +269,13 @@ class LoggingContext(object):
self.previous_context = None
self.alive = False
# if we have a parent, pass our CPU usage stats on
if self.parent_context is not None:
self.parent_context._resource_usage += self._resource_usage
# reset them in case we get entered again
self._resource_usage.reset()
def copy_to(self, record):
"""Copy logging fields from this context to a log record or
another LoggingContext