synapse/tests/util/test_batching_queue.py
2023-11-21 15:29:58 -05:00

250 lines
9.1 KiB
Python

#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# 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 typing import List, Tuple
from prometheus_client import Gauge
from twisted.internet import defer
from synapse.logging.context import make_deferred_yieldable
from synapse.util.batching_queue import (
BatchingQueue,
number_in_flight,
number_of_keys,
number_queued,
)
from tests.server import get_clock
from tests.unittest import TestCase
class BatchingQueueTestCase(TestCase):
def setUp(self) -> None:
self.clock, hs_clock = get_clock()
# We ensure that we remove any existing metrics for "test_queue".
try:
number_queued.remove("test_queue")
number_of_keys.remove("test_queue")
number_in_flight.remove("test_queue")
except KeyError:
pass
self._pending_calls: List[Tuple[List[str], defer.Deferred]] = []
self.queue: BatchingQueue[str, str] = BatchingQueue(
"test_queue", hs_clock, self._process_queue
)
async def _process_queue(self, values: List[str]) -> str:
d: "defer.Deferred[str]" = defer.Deferred()
self._pending_calls.append((values, d))
return await make_deferred_yieldable(d)
def _get_sample_with_name(self, metric: Gauge, name: str) -> float:
"""For a prometheus metric get the value of the sample that has a
matching "name" label.
"""
for sample in next(iter(metric.collect())).samples:
if sample.labels.get("name") == name:
return sample.value
self.fail("Found no matching sample")
def _assert_metrics(self, queued: int, keys: int, in_flight: int) -> None:
"""Assert that the metrics are correct"""
sample = self._get_sample_with_name(number_queued, self.queue._name)
self.assertEqual(
sample,
queued,
"number_queued",
)
sample = self._get_sample_with_name(number_of_keys, self.queue._name)
self.assertEqual(sample, keys, "number_of_keys")
sample = self._get_sample_with_name(number_in_flight, self.queue._name)
self.assertEqual(
sample,
in_flight,
"number_in_flight",
)
def test_simple(self) -> None:
"""Tests the basic case of calling `add_to_queue` once and having
`_process_queue` return.
"""
self.assertFalse(self._pending_calls)
queue_d = defer.ensureDeferred(self.queue.add_to_queue("foo"))
self._assert_metrics(queued=1, keys=1, in_flight=1)
# The queue should wait a reactor tick before calling the processing
# function.
self.assertFalse(self._pending_calls)
self.assertFalse(queue_d.called)
# We should see a call to `_process_queue` after a reactor tick.
self.clock.pump([0])
self.assertEqual(len(self._pending_calls), 1)
self.assertEqual(self._pending_calls[0][0], ["foo"])
self.assertFalse(queue_d.called)
self._assert_metrics(queued=0, keys=0, in_flight=1)
# Return value of the `_process_queue` should be propagated back.
self._pending_calls.pop()[1].callback("bar")
self.assertEqual(self.successResultOf(queue_d), "bar")
self._assert_metrics(queued=0, keys=0, in_flight=0)
def test_batching(self) -> None:
"""Test that multiple calls at the same time get batched up into one
call to `_process_queue`.
"""
self.assertFalse(self._pending_calls)
queue_d1 = defer.ensureDeferred(self.queue.add_to_queue("foo1"))
queue_d2 = defer.ensureDeferred(self.queue.add_to_queue("foo2"))
self._assert_metrics(queued=2, keys=1, in_flight=2)
self.clock.pump([0])
# We should see only *one* call to `_process_queue`
self.assertEqual(len(self._pending_calls), 1)
self.assertEqual(self._pending_calls[0][0], ["foo1", "foo2"])
self.assertFalse(queue_d1.called)
self.assertFalse(queue_d2.called)
self._assert_metrics(queued=0, keys=0, in_flight=2)
# Return value of the `_process_queue` should be propagated back to both.
self._pending_calls.pop()[1].callback("bar")
self.assertEqual(self.successResultOf(queue_d1), "bar")
self.assertEqual(self.successResultOf(queue_d2), "bar")
self._assert_metrics(queued=0, keys=0, in_flight=0)
def test_queuing(self) -> None:
"""Test that we queue up requests while a `_process_queue` is being
called.
"""
self.assertFalse(self._pending_calls)
queue_d1 = defer.ensureDeferred(self.queue.add_to_queue("foo1"))
self.clock.pump([0])
self.assertEqual(len(self._pending_calls), 1)
# We queue up work after the process function has been called, testing
# that they get correctly queued up.
queue_d2 = defer.ensureDeferred(self.queue.add_to_queue("foo2"))
queue_d3 = defer.ensureDeferred(self.queue.add_to_queue("foo3"))
# We should see only *one* call to `_process_queue`
self.assertEqual(len(self._pending_calls), 1)
self.assertEqual(self._pending_calls[0][0], ["foo1"])
self.assertFalse(queue_d1.called)
self.assertFalse(queue_d2.called)
self.assertFalse(queue_d3.called)
self._assert_metrics(queued=2, keys=1, in_flight=3)
# Return value of the `_process_queue` should be propagated back to the
# first.
self._pending_calls.pop()[1].callback("bar1")
self.assertEqual(self.successResultOf(queue_d1), "bar1")
self.assertFalse(queue_d2.called)
self.assertFalse(queue_d3.called)
self._assert_metrics(queued=2, keys=1, in_flight=2)
# We should now see a second call to `_process_queue`
self.clock.pump([0])
self.assertEqual(len(self._pending_calls), 1)
self.assertEqual(self._pending_calls[0][0], ["foo2", "foo3"])
self.assertFalse(queue_d2.called)
self.assertFalse(queue_d3.called)
self._assert_metrics(queued=0, keys=0, in_flight=2)
# Return value of the `_process_queue` should be propagated back to the
# second.
self._pending_calls.pop()[1].callback("bar2")
self.assertEqual(self.successResultOf(queue_d2), "bar2")
self.assertEqual(self.successResultOf(queue_d3), "bar2")
self._assert_metrics(queued=0, keys=0, in_flight=0)
def test_different_keys(self) -> None:
"""Test that calls to different keys get processed in parallel."""
self.assertFalse(self._pending_calls)
queue_d1 = defer.ensureDeferred(self.queue.add_to_queue("foo1", key=1))
self.clock.pump([0])
queue_d2 = defer.ensureDeferred(self.queue.add_to_queue("foo2", key=2))
self.clock.pump([0])
# We queue up another item with key=2 to check that we will keep taking
# things off the queue.
queue_d3 = defer.ensureDeferred(self.queue.add_to_queue("foo3", key=2))
# We should see two calls to `_process_queue`
self.assertEqual(len(self._pending_calls), 2)
self.assertEqual(self._pending_calls[0][0], ["foo1"])
self.assertEqual(self._pending_calls[1][0], ["foo2"])
self.assertFalse(queue_d1.called)
self.assertFalse(queue_d2.called)
self.assertFalse(queue_d3.called)
self._assert_metrics(queued=1, keys=1, in_flight=3)
# Return value of the `_process_queue` should be propagated back to the
# first.
self._pending_calls.pop(0)[1].callback("bar1")
self.assertEqual(self.successResultOf(queue_d1), "bar1")
self.assertFalse(queue_d2.called)
self.assertFalse(queue_d3.called)
self._assert_metrics(queued=1, keys=1, in_flight=2)
# Return value of the `_process_queue` should be propagated back to the
# second.
self._pending_calls.pop()[1].callback("bar2")
self.assertEqual(self.successResultOf(queue_d2), "bar2")
self.assertFalse(queue_d3.called)
# We should now see a call `_pending_calls` for `foo3`
self.clock.pump([0])
self.assertEqual(len(self._pending_calls), 1)
self.assertEqual(self._pending_calls[0][0], ["foo3"])
self.assertFalse(queue_d3.called)
self._assert_metrics(queued=0, keys=0, in_flight=1)
# Return value of the `_process_queue` should be propagated back to the
# third deferred.
self._pending_calls.pop()[1].callback("bar4")
self.assertEqual(self.successResultOf(queue_d3), "bar4")
self._assert_metrics(queued=0, keys=0, in_flight=0)