From 87b7d727605c8e122adb768b7487dfcae830593f Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 19 Jan 2018 23:51:04 +0000 Subject: [PATCH] Add some comments about the reactor tick time metric --- synapse/metrics/__init__.py | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/synapse/metrics/__init__.py b/synapse/metrics/__init__.py index 2265e6e8d..e0cfb7d08 100644 --- a/synapse/metrics/__init__.py +++ b/synapse/metrics/__init__.py @@ -146,10 +146,15 @@ def runUntilCurrentTimer(func): num_pending += 1 num_pending += len(reactor.threadCallQueue) - start = time.time() * 1000 ret = func(*args, **kwargs) end = time.time() * 1000 + + # record the amount of wallclock time spent running pending calls. + # This is a proxy for the actual amount of time between reactor polls, + # since about 25% of time is actually spent running things triggered by + # I/O events, but that is harder to capture without rewriting half the + # reactor. tick_time.inc_by(end - start) pending_calls_metric.inc_by(num_pending)