From b01a75549893bf4f8f986a74a499e7cb6131868c Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 20 Aug 2018 17:27:52 +0100 Subject: [PATCH] Make the in flight requests metrics thread safe --- synapse/http/request_metrics.py | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/synapse/http/request_metrics.py b/synapse/http/request_metrics.py index 588e280571..284d5e05de 100644 --- a/synapse/http/request_metrics.py +++ b/synapse/http/request_metrics.py @@ -15,6 +15,7 @@ # limitations under the License. import logging +import threading from prometheus_client.core import Counter, Histogram @@ -111,6 +112,9 @@ in_flight_requests_db_sched_duration = Counter( # The set of all in flight requests, set[RequestMetrics] _in_flight_requests = set() +# Protects the _in_flight_requests set from concurrent accesss +_in_flight_reqeuests_lock = threading.Lock() + def _get_in_flight_counts(): """Returns a count of all in flight requests by (method, server_name) @@ -120,7 +124,8 @@ def _get_in_flight_counts(): """ # Cast to a list to prevent it changing while the Prometheus # thread is collecting metrics - reqs = list(_in_flight_requests) + with _in_flight_reqeuests_lock: + reqs = list(_in_flight_requests) for rm in reqs: rm.update_metrics() @@ -154,10 +159,12 @@ class RequestMetrics(object): # to the "in flight" metrics. self._request_stats = self.start_context.get_resource_usage() - _in_flight_requests.add(self) + with _in_flight_reqeuests_lock: + _in_flight_requests.add(self) def stop(self, time_sec, request): - _in_flight_requests.discard(self) + with _in_flight_reqeuests_lock: + _in_flight_requests.discard(self) context = LoggingContext.current_context()