From 6a78ede56932b486c0ca3cc7c6edd84a2f373366 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Mon, 17 Jan 2022 12:14:40 +0000
Subject: Improve `reactor_tick_time` metric (#11724)

The existing implementation of the `python_twisted_reactor_tick_time` metric is pretty useless, because it *only*
measures the time taken to execute timed calls and callbacks from threads. That neglects everything that
happens off the back of I/O, which is obviously quite a lot for us.

To improve this, I've hooked into a different place in the reactor - in particular, where it calls `epoll`. That call is
the only place it should wait for something to happen - the rest of the loop *should* be quick.

I've also removed `python_twisted_reactor_pending_calls`, because I don't believe anyone ever looks at it, and
it's a nuisance to populate.
---
 contrib/prometheus/consoles/synapse.html | 16 ----------------
 1 file changed, 16 deletions(-)

(limited to 'contrib/prometheus')

diff --git a/contrib/prometheus/consoles/synapse.html b/contrib/prometheus/consoles/synapse.html
index cd9ad15231..d17c8a08d9 100644
--- a/contrib/prometheus/consoles/synapse.html
+++ b/contrib/prometheus/consoles/synapse.html
@@ -92,22 +92,6 @@ new PromConsole.Graph({
 })
 </script>
 
-<h3>Pending calls per tick</h3>
-<div id="reactor_pending_calls"></div>
-<script>
-new PromConsole.Graph({
-  node: document.querySelector("#reactor_pending_calls"),
-  expr: "rate(python_twisted_reactor_pending_calls_sum[30s]) / rate(python_twisted_reactor_pending_calls_count[30s])",
-  name: "[[job]]-[[index]]",
-  min: 0,
-  renderer: "line",
-  height: 150,
-  yAxisFormatter: PromConsole.NumberFormatter.humanize,
-  yHoverFormatter: PromConsole.NumberFormatter.humanize,
-  yTitle: "Pending Calls"
-})
-</script>
-
 <h1>Storage</h1>
 
 <h3>Queries</h3>
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