diff --git a/synapse/metrics/metric.py b/synapse/metrics/metric.py
index 8a497fc154..7e47f86155 100644
--- a/synapse/metrics/metric.py
+++ b/synapse/metrics/metric.py
@@ -76,19 +76,24 @@ class CallbackMetric(BaseMetric):
# TODO(paul): work out something we can do with keys and vectors
return ["%s %d" % (self.name, self.callback())]
-class CacheCounterMetric(object):
+class CacheMetric(object):
"""A combination of two CounterMetrics, one to count cache hits and one to
- count misses.
+ count misses, and a callback metric to yield the current size.
This metric generates standard metric name pairs, so that monitoring rules
can easily be applied to measure hit ratio."""
- def __init__(self, name, keys=[]):
+ def __init__(self, name, size_callback, keys=[]):
self.name = name
self.hits = CounterMetric(name + ":hits", keys=keys)
self.misses = CounterMetric(name + ":misses", keys=keys)
+ self.size = CallbackMetric(name + ":size",
+ callback=size_callback,
+ keys=keys,
+ )
+
def inc_hits(self, *values):
self.hits.inc(*values)
@@ -96,4 +101,4 @@ class CacheCounterMetric(object):
self.misses.inc(*values)
def render(self):
- return self.hits.render() + self.misses.render()
+ return self.hits.render() + self.misses.render() + self.size.render()
|
