synapse/tests/util/test_retryutils.py
Patrick Cloke 77dfc1f939
Fix a bug where servers could be marked as up when they were failing (#16506)
After this change a server will only be reported as back online
if they were previously having requests fail.
2023-10-17 07:32:40 -04:00

236 lines
8.4 KiB
Python

# Copyright 2019 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from unittest import mock
from synapse.notifier import Notifier
from synapse.replication.tcp.handler import ReplicationCommandHandler
from synapse.util.retryutils import NotRetryingDestination, get_retry_limiter
from tests.unittest import HomeserverTestCase
class RetryLimiterTestCase(HomeserverTestCase):
def test_new_destination(self) -> None:
"""A happy-path case with a new destination and a successful operation"""
store = self.hs.get_datastores().main
limiter = self.get_success(get_retry_limiter("test_dest", self.clock, store))
# advance the clock a bit before making the request
self.pump(1)
with limiter:
pass
new_timings = self.get_success(store.get_destination_retry_timings("test_dest"))
self.assertIsNone(new_timings)
def test_limiter(self) -> None:
"""General test case which walks through the process of a failing request"""
store = self.hs.get_datastores().main
limiter = self.get_success(get_retry_limiter("test_dest", self.clock, store))
min_retry_interval_ms = (
self.hs.config.federation.destination_min_retry_interval_ms
)
retry_multiplier = self.hs.config.federation.destination_retry_multiplier
self.pump(1)
try:
with limiter:
self.pump(1)
failure_ts = self.clock.time_msec()
raise AssertionError("argh")
except AssertionError:
pass
self.pump()
new_timings = self.get_success(store.get_destination_retry_timings("test_dest"))
assert new_timings is not None
self.assertEqual(new_timings.failure_ts, failure_ts)
self.assertEqual(new_timings.retry_last_ts, failure_ts)
self.assertEqual(new_timings.retry_interval, min_retry_interval_ms)
# now if we try again we should get a failure
self.get_failure(
get_retry_limiter("test_dest", self.clock, store), NotRetryingDestination
)
#
# advance the clock and try again
#
self.pump(min_retry_interval_ms)
limiter = self.get_success(get_retry_limiter("test_dest", self.clock, store))
self.pump(1)
try:
with limiter:
self.pump(1)
retry_ts = self.clock.time_msec()
raise AssertionError("argh")
except AssertionError:
pass
self.pump()
new_timings = self.get_success(store.get_destination_retry_timings("test_dest"))
assert new_timings is not None
self.assertEqual(new_timings.failure_ts, failure_ts)
self.assertEqual(new_timings.retry_last_ts, retry_ts)
self.assertGreaterEqual(
new_timings.retry_interval, min_retry_interval_ms * retry_multiplier * 0.5
)
self.assertLessEqual(
new_timings.retry_interval, min_retry_interval_ms * retry_multiplier * 2.0
)
#
# one more go, with success
#
self.reactor.advance(min_retry_interval_ms * retry_multiplier * 2.0)
limiter = self.get_success(get_retry_limiter("test_dest", self.clock, store))
self.pump(1)
with limiter:
self.pump(1)
# wait for the update to land
self.pump()
new_timings = self.get_success(store.get_destination_retry_timings("test_dest"))
self.assertIsNone(new_timings)
def test_notifier_replication(self) -> None:
"""Ensure the notifier/replication client is called only when expected."""
store = self.hs.get_datastores().main
notifier = mock.Mock(spec=Notifier)
replication_client = mock.Mock(spec=ReplicationCommandHandler)
limiter = self.get_success(
get_retry_limiter(
"test_dest",
self.clock,
store,
notifier=notifier,
replication_client=replication_client,
)
)
# The server is already up, nothing should occur.
self.pump(1)
with limiter:
pass
self.pump()
new_timings = self.get_success(store.get_destination_retry_timings("test_dest"))
self.assertIsNone(new_timings)
notifier.notify_remote_server_up.assert_not_called()
replication_client.send_remote_server_up.assert_not_called()
# Attempt again, but return an error. This will cause new retry timings, but
# should not trigger server up notifications.
self.pump(1)
try:
with limiter:
raise AssertionError("argh")
except AssertionError:
pass
self.pump()
new_timings = self.get_success(store.get_destination_retry_timings("test_dest"))
# The exact retry timings are tested separately.
self.assertIsNotNone(new_timings)
notifier.notify_remote_server_up.assert_not_called()
replication_client.send_remote_server_up.assert_not_called()
# A second failing request should be treated as the above.
self.pump(1)
try:
with limiter:
raise AssertionError("argh")
except AssertionError:
pass
self.pump()
new_timings = self.get_success(store.get_destination_retry_timings("test_dest"))
# The exact retry timings are tested separately.
self.assertIsNotNone(new_timings)
notifier.notify_remote_server_up.assert_not_called()
replication_client.send_remote_server_up.assert_not_called()
# A final successful attempt should generate a server up notification.
self.pump(1)
with limiter:
pass
self.pump()
new_timings = self.get_success(store.get_destination_retry_timings("test_dest"))
# The exact retry timings are tested separately.
self.assertIsNone(new_timings)
notifier.notify_remote_server_up.assert_called_once_with("test_dest")
replication_client.send_remote_server_up.assert_called_once_with("test_dest")
def test_max_retry_interval(self) -> None:
"""Test that `destination_max_retry_interval` setting works as expected"""
store = self.hs.get_datastores().main
destination_max_retry_interval_ms = (
self.hs.config.federation.destination_max_retry_interval_ms
)
self.get_success(get_retry_limiter("test_dest", self.clock, store))
self.pump(1)
failure_ts = self.clock.time_msec()
# Simulate reaching destination_max_retry_interval
self.get_success(
store.set_destination_retry_timings(
"test_dest",
failure_ts=failure_ts,
retry_last_ts=failure_ts,
retry_interval=destination_max_retry_interval_ms,
)
)
# Check it fails
self.get_failure(
get_retry_limiter("test_dest", self.clock, store), NotRetryingDestination
)
# Get past retry_interval and we can try again, and still throw an error to continue the backoff
self.reactor.advance(destination_max_retry_interval_ms / 1000 + 1)
limiter = self.get_success(get_retry_limiter("test_dest", self.clock, store))
self.pump(1)
try:
with limiter:
self.pump(1)
raise AssertionError("argh")
except AssertionError:
pass
self.pump()
# retry_interval does not increase and stays at destination_max_retry_interval_ms
new_timings = self.get_success(store.get_destination_retry_timings("test_dest"))
assert new_timings is not None
self.assertEqual(new_timings.retry_interval, destination_max_retry_interval_ms)
# Check it fails
self.get_failure(
get_retry_limiter("test_dest", self.clock, store), NotRetryingDestination
)