diff options
| -rw-r--r-- | synapse/metrics/__init__.py | 11 | ||||
| -rw-r--r-- | synapse/metrics/metric.py | 43 | ||||
| -rw-r--r-- | tests/metrics/test_metric.py | 27 |
3 files changed, 73 insertions, 8 deletions
diff --git a/synapse/metrics/__init__.py b/synapse/metrics/__init__.py index 125845eb30..d5c30bbe41 100644 --- a/synapse/metrics/__init__.py +++ b/synapse/metrics/__init__.py @@ -13,7 +13,7 @@ # See the License for the specific language governing permissions and # limitations under the License. -from .metric import CounterMetric +from .metric import CounterMetric, CacheCounterMetric # We'll keep all the available metrics in a single toplevel dict, one shared @@ -43,6 +43,15 @@ class Metrics(object): return metric + def register_cachecounter(self, name, *args, **kwargs): + full_name = "%s.%s" % (self.name_prefix, name) + + metric = CacheCounterMetric(full_name, *args, **kwargs) + + self._register(metric) + + return metric + def counted(self, func): """ A method decorator that registers a counter, to count invocations of this method. """ diff --git a/synapse/metrics/metric.py b/synapse/metrics/metric.py index f5a98763cc..00b149f6f6 100644 --- a/synapse/metrics/metric.py +++ b/synapse/metrics/metric.py @@ -14,16 +14,28 @@ # limitations under the License. -class CounterMetric(object): +class BaseMetric(object): def __init__(self, name, keys=[]): self.name = name self.keys = keys # OK not to clone as we never write it + def _render_key(self, values): + # TODO: some kind of value escape + return ",".join(["%s=%s" % kv for kv in zip(self.keys, values)]) + + +class CounterMetric(BaseMetric): + """The simplest kind of metric; one that stores a monotonically-increasing + integer that counts events.""" + + def __init__(self, *args, **kwargs): + super(CounterMetric, self).__init__(*args, **kwargs) + self.counts = {} # Scalar metrics are never empty - if not len(keys): + if not len(self.keys): self.counts[()] = 0 def inc(self, *values): @@ -42,13 +54,32 @@ class CounterMetric(object): def fetch(self): return dict(self.counts) - def _render_key(self, values): - # TODO: some kind of value escape - return ",".join(["%s=%s" % kv for kv in zip(self.keys, values)]) - def render(self): if not len(self.keys): return ["%s %d" % (self.name, self.counts[()])] return ["%s{%s} %d" % (self.name, self._render_key(k), self.counts[k]) for k in sorted(self.counts.keys())] + + +class CacheCounterMetric(object): + """A combination of two CounterMetrics, one to count cache hits and one to + count misses. + + This metric generates standard metric name pairs, so that monitoring rules + can easily be applied to measure hit ratio.""" + + def __init__(self, name, keys=[]): + self.name = name + + self.hits = CounterMetric(name + ":hits", keys=keys) + self.misses = CounterMetric(name + ":misses", keys=keys) + + def inc_hits(self, *values): + self.hits.inc(*values) + + def inc_misses(self, *values): + self.misses.inc(*values) + + def render(self): + return self.hits.render() + self.misses.render() diff --git a/tests/metrics/test_metric.py b/tests/metrics/test_metric.py index a4fd52a9d5..93e8e27e4f 100644 --- a/tests/metrics/test_metric.py +++ b/tests/metrics/test_metric.py @@ -15,7 +15,7 @@ from tests import unittest -from synapse.metrics.metric import CounterMetric +from synapse.metrics.metric import CounterMetric, CacheCounterMetric class CounterMetricTestCase(unittest.TestCase): @@ -59,3 +59,28 @@ class CounterMetricTestCase(unittest.TestCase): "vector{method=GET} 2", "vector{method=PUT} 1", ]) + + +class CacheCounterMetricTestCase(unittest.TestCase): + + def test_cachecounter(self): + counter = CacheCounterMetric("cache") + + self.assertEquals(counter.render(), [ + "cache:hits 0", + "cache:misses 0", + ]) + + counter.inc_misses() + + self.assertEquals(counter.render(), [ + "cache:hits 0", + "cache:misses 1", + ]) + + counter.inc_hits() + + self.assertEquals(counter.render(), [ + "cache:hits 1", + "cache:misses 1", + ]) |