From 19d274085fa939c440667759d38a8a255216899b Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 12 Jan 2018 23:21:32 +0000 Subject: [PATCH] Make Counter render floats Prometheus handles all metrics as floats, and sometimes we store non-integer values in them (notably, durations in seconds), so let's render them as floats too. (Note that the standard client libraries also treat Counters as floats.) --- synapse/metrics/metric.py | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/synapse/metrics/metric.py b/synapse/metrics/metric.py index e87b2b80a..1d054dd55 100644 --- a/synapse/metrics/metric.py +++ b/synapse/metrics/metric.py @@ -50,7 +50,14 @@ class BaseMetric(object): class CounterMetric(BaseMetric): """The simplest kind of metric; one that stores a monotonically-increasing - integer that counts events.""" + value that counts events or running totals. + + Example use cases for Counters: + - Number of requests processed + - Number of items that were inserted into a queue + - Total amount of data that a system has processed + Counters can only go up (and be reset when the process restarts). + """ def __init__(self, *args, **kwargs): super(CounterMetric, self).__init__(*args, **kwargs) @@ -59,7 +66,7 @@ class CounterMetric(BaseMetric): # Scalar metrics are never empty if self.is_scalar(): - self.counts[()] = 0 + self.counts[()] = 0. def inc_by(self, incr, *values): if len(values) != self.dimension(): @@ -78,7 +85,7 @@ class CounterMetric(BaseMetric): self.inc_by(1, *values) def render_item(self, k): - return ["%s%s %d" % (self.name, self._render_key(k), self.counts[k])] + return ["%s%s %.12g" % (self.name, self._render_key(k), self.counts[k])] def render(self): return map_concat(self.render_item, sorted(self.counts.keys()))