synapse/tests/util/test_retryutils.py
Eric Eastwood b7e7f537f1
Refactor background process metrics to be homeserver-scoped (#18670)
Part of https://github.com/element-hq/synapse/issues/18592

Separated out of https://github.com/element-hq/synapse/pull/18656
because it's a bigger, unique piece of the refactor


### Testing strategy

 1. Add the `metrics` listener in your `homeserver.yaml`
    ```yaml
    listeners:
      # This is just showing how to configure metrics either way
      #
      # `http` `metrics` resource
      - port: 9322
        type: http
        bind_addresses: ['127.0.0.1']
        resources:
          - names: [metrics]
            compress: false
      # `metrics` listener
      - port: 9323
        type: metrics
        bind_addresses: ['127.0.0.1']
    ```
1. Start the homeserver: `poetry run synapse_homeserver --config-path
homeserver.yaml`
1. Fetch `http://localhost:9322/_synapse/metrics` and/or
`http://localhost:9323/metrics`
1. Observe response includes the background processs metrics
(`synapse_background_process_start_count`,
`synapse_background_process_db_txn_count_total`, etc) with the
`server_name` label
2025-07-23 13:28:17 -05:00

305 lines
9.9 KiB
Python

#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright 2019 The 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 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(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=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(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=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(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=store,
),
NotRetryingDestination,
)
#
# advance the clock and try again
#
self.pump(min_retry_interval_ms)
limiter = self.get_success(
get_retry_limiter(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=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(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=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(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=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(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=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(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=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(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=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(
destination="test_dest",
our_server_name=self.hs.hostname,
clock=self.clock,
store=store,
),
NotRetryingDestination,
)