synapse/tests/metrics/test_metrics.py
Erik Johnston 23740eaa3d
Correctly mention previous copyright (#16820)
During the migration the automated script to update the copyright
headers accidentally got rid of some of the existing copyright lines.
Reinstate them.
2024-01-23 11:26:48 +00:00

214 lines
7.1 KiB
Python

#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright 2019 Matrix.org Foundation C.I.C.
# Copyright (C) 2023 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#
from importlib import metadata
from typing import Dict, Tuple
from unittest.mock import patch
from pkg_resources import parse_version
from prometheus_client.core import Sample
from typing_extensions import Protocol
from synapse.app._base import _set_prometheus_client_use_created_metrics
from synapse.metrics import REGISTRY, InFlightGauge, generate_latest
from synapse.util.caches.deferred_cache import DeferredCache
from tests import unittest
def get_sample_labels_value(sample: Sample) -> Tuple[Dict[str, str], float]:
"""Extract the labels and values of a sample.
prometheus_client 0.5 changed the sample type to a named tuple with more
members than the plain tuple had in 0.4 and earlier. This function can
extract the labels and value from the sample for both sample types.
Args:
sample: The sample to get the labels and value from.
Returns:
A tuple of (labels, value) from the sample.
"""
# If the sample has a labels and value attribute, use those.
if hasattr(sample, "labels") and hasattr(sample, "value"):
return sample.labels, sample.value
# Otherwise fall back to treating it as a plain 3 tuple.
else:
# In older versions of prometheus_client Sample was a 3-tuple.
labels: Dict[str, str]
value: float
_, labels, value = sample # type: ignore[misc]
return labels, value
class TestMauLimit(unittest.TestCase):
def test_basic(self) -> None:
class MetricEntry(Protocol):
foo: int
bar: int
gauge: InFlightGauge[MetricEntry] = InFlightGauge(
"test1", "", labels=["test_label"], sub_metrics=["foo", "bar"]
)
def handle1(metrics: MetricEntry) -> None:
metrics.foo += 2
metrics.bar = max(metrics.bar, 5)
def handle2(metrics: MetricEntry) -> None:
metrics.foo += 3
metrics.bar = max(metrics.bar, 7)
gauge.register(("key1",), handle1)
self.assert_dict(
{
"test1_total": {("key1",): 1},
"test1_foo": {("key1",): 2},
"test1_bar": {("key1",): 5},
},
self.get_metrics_from_gauge(gauge),
)
gauge.unregister(("key1",), handle1)
self.assert_dict(
{
"test1_total": {("key1",): 0},
"test1_foo": {("key1",): 0},
"test1_bar": {("key1",): 0},
},
self.get_metrics_from_gauge(gauge),
)
gauge.register(("key1",), handle1)
gauge.register(("key2",), handle2)
self.assert_dict(
{
"test1_total": {("key1",): 1, ("key2",): 1},
"test1_foo": {("key1",): 2, ("key2",): 3},
"test1_bar": {("key1",): 5, ("key2",): 7},
},
self.get_metrics_from_gauge(gauge),
)
gauge.unregister(("key2",), handle2)
gauge.register(("key1",), handle2)
self.assert_dict(
{
"test1_total": {("key1",): 2, ("key2",): 0},
"test1_foo": {("key1",): 5, ("key2",): 0},
"test1_bar": {("key1",): 7, ("key2",): 0},
},
self.get_metrics_from_gauge(gauge),
)
def get_metrics_from_gauge(
self, gauge: InFlightGauge
) -> Dict[str, Dict[Tuple[str, ...], float]]:
results = {}
for r in gauge.collect():
results[r.name] = {
tuple(labels[x] for x in gauge.labels): value
for labels, value in map(get_sample_labels_value, r.samples)
}
return results
class BuildInfoTests(unittest.TestCase):
def test_get_build(self) -> None:
"""
The synapse_build_info metric reports the OS version, Python version,
and Synapse version.
"""
items = list(
filter(
lambda x: b"synapse_build_info{" in x,
generate_latest(REGISTRY).split(b"\n"),
)
)
self.assertEqual(len(items), 1)
self.assertTrue(b"osversion=" in items[0])
self.assertTrue(b"pythonversion=" in items[0])
self.assertTrue(b"version=" in items[0])
class CacheMetricsTests(unittest.HomeserverTestCase):
def test_cache_metric(self) -> None:
"""
Caches produce metrics reflecting their state when scraped.
"""
CACHE_NAME = "cache_metrics_test_fgjkbdfg"
cache: DeferredCache[str, str] = DeferredCache(CACHE_NAME, max_entries=777)
items = {
x.split(b"{")[0].decode("ascii"): x.split(b" ")[1].decode("ascii")
for x in filter(
lambda x: b"cache_metrics_test_fgjkbdfg" in x,
generate_latest(REGISTRY).split(b"\n"),
)
}
self.assertEqual(items["synapse_util_caches_cache_size"], "0.0")
self.assertEqual(items["synapse_util_caches_cache_max_size"], "777.0")
cache.prefill("1", "hi")
items = {
x.split(b"{")[0].decode("ascii"): x.split(b" ")[1].decode("ascii")
for x in filter(
lambda x: b"cache_metrics_test_fgjkbdfg" in x,
generate_latest(REGISTRY).split(b"\n"),
)
}
self.assertEqual(items["synapse_util_caches_cache_size"], "1.0")
self.assertEqual(items["synapse_util_caches_cache_max_size"], "777.0")
class PrometheusMetricsHackTestCase(unittest.HomeserverTestCase):
if parse_version(metadata.version("prometheus_client")) < parse_version("0.14.0"):
skip = "prometheus-client too old"
def test_created_metrics_disabled(self) -> None:
"""
Tests that a brittle hack, to disable `_created` metrics, works.
This involves poking at the internals of prometheus-client.
It's not the end of the world if this doesn't work.
This test gives us a way to notice if prometheus-client changes
their internals.
"""
import prometheus_client.metrics
PRIVATE_FLAG_NAME = "_use_created"
# By default, the pesky `_created` metrics are enabled.
# Check this assumption is still valid.
self.assertTrue(getattr(prometheus_client.metrics, PRIVATE_FLAG_NAME))
with patch("prometheus_client.metrics") as mock:
setattr(mock, PRIVATE_FLAG_NAME, True)
_set_prometheus_client_use_created_metrics(False)
self.assertFalse(getattr(mock, PRIVATE_FLAG_NAME, False))