From 2f5a77efae98cf5936d47473a31504f73d1d2315 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 1 Jul 2024 12:48:36 +0100 Subject: [PATCH] Limit size of presence EDUs (#17371) Otherwise they are unbounded. --------- Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com> --- changelog.d/17371.misc | 1 + .../sender/per_destination_queue.py | 31 +++-- tests/federation/test_federation_sender.py | 119 ++++++++++++++++++ 3 files changed, 140 insertions(+), 11 deletions(-) create mode 100644 changelog.d/17371.misc diff --git a/changelog.d/17371.misc b/changelog.d/17371.misc new file mode 100644 index 000000000..0fbf19f4f --- /dev/null +++ b/changelog.d/17371.misc @@ -0,0 +1 @@ +Limit size of presence EDUs to 50 entries. diff --git a/synapse/federation/sender/per_destination_queue.py b/synapse/federation/sender/per_destination_queue.py index d9f2f017e..9f1c2fe22 100644 --- a/synapse/federation/sender/per_destination_queue.py +++ b/synapse/federation/sender/per_destination_queue.py @@ -21,6 +21,7 @@ # import datetime import logging +from collections import OrderedDict from types import TracebackType from typing import TYPE_CHECKING, Dict, Hashable, Iterable, List, Optional, Tuple, Type @@ -68,6 +69,10 @@ sent_edus_by_type = Counter( # If the retry interval is larger than this then we enter "catchup" mode CATCHUP_RETRY_INTERVAL = 60 * 60 * 1000 +# Limit how many presence states we add to each presence EDU, to ensure that +# they are bounded in size. +MAX_PRESENCE_STATES_PER_EDU = 50 + class PerDestinationQueue: """ @@ -144,7 +149,7 @@ class PerDestinationQueue: # Map of user_id -> UserPresenceState of pending presence to be sent to this # destination - self._pending_presence: Dict[str, UserPresenceState] = {} + self._pending_presence: OrderedDict[str, UserPresenceState] = OrderedDict() # List of room_id -> receipt_type -> user_id -> receipt_dict, # @@ -399,7 +404,7 @@ class PerDestinationQueue: # through another mechanism, because this is all volatile! self._pending_edus = [] self._pending_edus_keyed = {} - self._pending_presence = {} + self._pending_presence.clear() self._pending_receipt_edus = [] self._start_catching_up() @@ -721,22 +726,26 @@ class _TransactionQueueManager: # Add presence EDU. if self.queue._pending_presence: + # Only send max 50 presence entries in the EDU, to bound the amount + # of data we're sending. + presence_to_add: List[JsonDict] = [] + while ( + self.queue._pending_presence + and len(presence_to_add) < MAX_PRESENCE_STATES_PER_EDU + ): + _, presence = self.queue._pending_presence.popitem(last=False) + presence_to_add.append( + format_user_presence_state(presence, self.queue._clock.time_msec()) + ) + pending_edus.append( Edu( origin=self.queue._server_name, destination=self.queue._destination, edu_type=EduTypes.PRESENCE, - content={ - "push": [ - format_user_presence_state( - presence, self.queue._clock.time_msec() - ) - for presence in self.queue._pending_presence.values() - ] - }, + content={"push": presence_to_add}, ) ) - self.queue._pending_presence = {} # Add read receipt EDUs. pending_edus.extend(self.queue._get_receipt_edus(force_flush=False, limit=5)) diff --git a/tests/federation/test_federation_sender.py b/tests/federation/test_federation_sender.py index 9073afc70..6a8887fe7 100644 --- a/tests/federation/test_federation_sender.py +++ b/tests/federation/test_federation_sender.py @@ -27,6 +27,8 @@ from twisted.internet import defer from twisted.test.proto_helpers import MemoryReactor from synapse.api.constants import EduTypes, RoomEncryptionAlgorithms +from synapse.api.presence import UserPresenceState +from synapse.federation.sender.per_destination_queue import MAX_PRESENCE_STATES_PER_EDU from synapse.federation.units import Transaction from synapse.handlers.device import DeviceHandler from synapse.rest import admin @@ -266,6 +268,123 @@ class FederationSenderReceiptsTestCases(HomeserverTestCase): ) +class FederationSenderPresenceTestCases(HomeserverTestCase): + """ + Test federation sending for presence updates. + """ + + def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer: + self.federation_transport_client = Mock(spec=["send_transaction"]) + self.federation_transport_client.send_transaction = AsyncMock() + hs = self.setup_test_homeserver( + federation_transport_client=self.federation_transport_client, + ) + + return hs + + def default_config(self) -> JsonDict: + config = super().default_config() + config["federation_sender_instances"] = None + return config + + def test_presence_simple(self) -> None: + "Test that sending a single presence update works" + + mock_send_transaction: AsyncMock = ( + self.federation_transport_client.send_transaction + ) + mock_send_transaction.return_value = {} + + sender = self.hs.get_federation_sender() + self.get_success( + sender.send_presence_to_destinations( + [UserPresenceState.default("@user:test")], + ["server"], + ) + ) + + self.pump() + + # expect a call to send_transaction + mock_send_transaction.assert_awaited_once() + + json_cb = mock_send_transaction.call_args[0][1] + data = json_cb() + self.assertEqual( + data["edus"], + [ + { + "edu_type": EduTypes.PRESENCE, + "content": { + "push": [ + { + "presence": "offline", + "user_id": "@user:test", + } + ] + }, + } + ], + ) + + def test_presence_batched(self) -> None: + """Test that sending lots of presence updates to a destination are + batched, rather than having them all sent in one EDU.""" + + mock_send_transaction: AsyncMock = ( + self.federation_transport_client.send_transaction + ) + mock_send_transaction.return_value = {} + + sender = self.hs.get_federation_sender() + + # We now send lots of presence updates to force the federation sender to + # batch the mup. + number_presence_updates_to_send = MAX_PRESENCE_STATES_PER_EDU * 2 + self.get_success( + sender.send_presence_to_destinations( + [ + UserPresenceState.default(f"@user{i}:test") + for i in range(number_presence_updates_to_send) + ], + ["server"], + ) + ) + + self.pump() + + # We should have seen at least one transcation be sent by now. + mock_send_transaction.assert_called() + + # We don't want to specify exactly how the presence EDUs get sent out, + # could be one per transaction or multiple per transaction. We just want + # to assert that a) each presence EDU has bounded number of updates, and + # b) that all updates get sent out. + presence_edus = [] + for transaction_call in mock_send_transaction.call_args_list: + json_cb = transaction_call[0][1] + data = json_cb() + + for edu in data["edus"]: + self.assertEqual(edu.get("edu_type"), EduTypes.PRESENCE) + presence_edus.append(edu) + + # A set of all user presence we see, this should end up matching the + # number we sent out above. + seen_users: Set[str] = set() + + for edu in presence_edus: + presence_states = edu["content"]["push"] + + # This is where we actually check that the number of presence + # updates is bounded. + self.assertLessEqual(len(presence_states), MAX_PRESENCE_STATES_PER_EDU) + + seen_users.update(p["user_id"] for p in presence_states) + + self.assertEqual(len(seen_users), number_presence_updates_to_send) + + class FederationSenderDevicesTestCases(HomeserverTestCase): """ Test federation sending to update devices.