Faster joins: persist to database (#12012)

When we get a partial_state response from send_join, store information in the
database about it:
 * store a record about the room as a whole having partial state, and stash the
   list of member servers too.
 * flag the join event itself as having partial state
 * also, for any new events whose prev-events are partial-stated, note that
   they will *also* be partial-stated.

We don't yet make any attempt to interpret this data, so API calls (and a bunch
of other things) are just going to get incorrect data.
This commit is contained in:
Richard van der Hoff 2022-03-01 12:49:54 +00:00 committed by GitHub
parent 4ccc2d09aa
commit e2e1d90a5e
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
12 changed files with 297 additions and 32 deletions

1
changelog.d/12012.misc Normal file
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@ -0,0 +1 @@
Preparation for faster-room-join work: persist information on which events and rooms have partial state to the database.

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@ -101,6 +101,9 @@ class EventContext:
As with _current_state_ids, this is a private attribute. It should be
accessed via get_prev_state_ids.
partial_state: if True, we may be storing this event with a temporary,
incomplete state.
"""
rejected: Union[bool, str] = False
@ -113,12 +116,15 @@ class EventContext:
_current_state_ids: Optional[StateMap[str]] = None
_prev_state_ids: Optional[StateMap[str]] = None
partial_state: bool = False
@staticmethod
def with_state(
state_group: Optional[int],
state_group_before_event: Optional[int],
current_state_ids: Optional[StateMap[str]],
prev_state_ids: Optional[StateMap[str]],
partial_state: bool,
prev_group: Optional[int] = None,
delta_ids: Optional[StateMap[str]] = None,
) -> "EventContext":
@ -129,6 +135,7 @@ class EventContext:
state_group_before_event=state_group_before_event,
prev_group=prev_group,
delta_ids=delta_ids,
partial_state=partial_state,
)
@staticmethod
@ -170,6 +177,7 @@ class EventContext:
"prev_group": self.prev_group,
"delta_ids": _encode_state_dict(self.delta_ids),
"app_service_id": self.app_service.id if self.app_service else None,
"partial_state": self.partial_state,
}
@staticmethod
@ -196,6 +204,7 @@ class EventContext:
prev_group=input["prev_group"],
delta_ids=_decode_state_dict(input["delta_ids"]),
rejected=input["rejected"],
partial_state=input.get("partial_state", False),
)
app_service_id = input["app_service_id"]

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@ -519,8 +519,17 @@ class FederationHandler:
state_events=state,
)
if ret.partial_state:
await self.store.store_partial_state_room(room_id, ret.servers_in_room)
max_stream_id = await self._federation_event_handler.process_remote_join(
origin, room_id, auth_chain, state, event, room_version_obj
origin,
room_id,
auth_chain,
state,
event,
room_version_obj,
partial_state=ret.partial_state,
)
# We wait here until this instance has seen the events come down

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@ -397,6 +397,7 @@ class FederationEventHandler:
state: List[EventBase],
event: EventBase,
room_version: RoomVersion,
partial_state: bool,
) -> int:
"""Persists the events returned by a send_join
@ -412,6 +413,7 @@ class FederationEventHandler:
event
room_version: The room version we expect this room to have, and
will raise if it doesn't match the version in the create event.
partial_state: True if the state omits non-critical membership events
Returns:
The stream ID after which all events have been persisted.
@ -453,10 +455,14 @@ class FederationEventHandler:
)
# and now persist the join event itself.
logger.info("Peristing join-via-remote %s", event)
logger.info(
"Peristing join-via-remote %s (partial_state: %s)", event, partial_state
)
with nested_logging_context(suffix=event.event_id):
context = await self._state_handler.compute_event_context(
event, old_state=state
event,
old_state=state,
partial_state=partial_state,
)
context = await self._check_event_auth(origin, event, context)
@ -698,6 +704,8 @@ class FederationEventHandler:
try:
state = await self._resolve_state_at_missing_prevs(origin, event)
# TODO(faster_joins): make sure that _resolve_state_at_missing_prevs does
# not return partial state
await self._process_received_pdu(
origin, event, state=state, backfilled=backfilled
)
@ -1791,6 +1799,7 @@ class FederationEventHandler:
prev_state_ids=prev_state_ids,
prev_group=prev_group,
delta_ids=state_updates,
partial_state=context.partial_state,
)
async def _run_push_actions_and_persist_event(

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@ -992,6 +992,8 @@ class EventCreationHandler:
and full_state_ids_at_event
and builder.internal_metadata.is_historical()
):
# TODO(faster_joins): figure out how this works, and make sure that the
# old state is complete.
old_state = await self.store.get_events_as_list(full_state_ids_at_event)
context = await self.state.compute_event_context(event, old_state=old_state)
else:

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@ -258,7 +258,10 @@ class StateHandler:
return await self.store.get_joined_hosts(room_id, entry)
async def compute_event_context(
self, event: EventBase, old_state: Optional[Iterable[EventBase]] = None
self,
event: EventBase,
old_state: Optional[Iterable[EventBase]] = None,
partial_state: bool = False,
) -> EventContext:
"""Build an EventContext structure for a non-outlier event.
@ -273,6 +276,8 @@ class StateHandler:
calculated from existing events. This is normally only specified
when receiving an event from federation where we don't have the
prev events for, e.g. when backfilling.
partial_state: True if `old_state` is partial and omits non-critical
membership events
Returns:
The event context.
"""
@ -295,8 +300,28 @@ class StateHandler:
else:
# otherwise, we'll need to resolve the state across the prev_events.
logger.debug("calling resolve_state_groups from compute_event_context")
# partial_state should not be set explicitly in this case:
# we work it out dynamically
assert not partial_state
# if any of the prev-events have partial state, so do we.
# (This is slightly racy - the prev-events might get fixed up before we use
# their states - but I don't think that really matters; it just means we
# might redundantly recalculate the state for this event later.)
prev_event_ids = event.prev_event_ids()
incomplete_prev_events = await self.store.get_partial_state_events(
prev_event_ids
)
if any(incomplete_prev_events.values()):
logger.debug(
"New/incoming event %s refers to prev_events %s with partial state",
event.event_id,
[k for (k, v) in incomplete_prev_events.items() if v],
)
partial_state = True
logger.debug("calling resolve_state_groups from compute_event_context")
entry = await self.resolve_state_groups_for_events(
event.room_id, event.prev_event_ids()
)
@ -342,6 +367,7 @@ class StateHandler:
prev_state_ids=state_ids_before_event,
prev_group=state_group_before_event_prev_group,
delta_ids=deltas_to_state_group_before_event,
partial_state=partial_state,
)
#
@ -373,6 +399,7 @@ class StateHandler:
prev_state_ids=state_ids_before_event,
prev_group=state_group_before_event,
delta_ids=delta_ids,
partial_state=partial_state,
)
@measure_func()

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@ -2145,6 +2145,14 @@ class PersistEventsStore:
state_groups = {}
for event, context in events_and_contexts:
if event.internal_metadata.is_outlier():
# double-check that we don't have any events that claim to be outliers
# *and* have partial state (which is meaningless: we should have no
# state at all for an outlier)
if context.partial_state:
raise ValueError(
"Outlier event %s claims to have partial state", event.event_id
)
continue
# if the event was rejected, just give it the same state as its
@ -2155,6 +2163,23 @@ class PersistEventsStore:
state_groups[event.event_id] = context.state_group
# if we have partial state for these events, record the fact. (This happens
# here rather than in _store_event_txn because it also needs to happen when
# we de-outlier an event.)
self.db_pool.simple_insert_many_txn(
txn,
table="partial_state_events",
keys=("room_id", "event_id"),
values=[
(
event.room_id,
event.event_id,
)
for event, ctx in events_and_contexts
if ctx.partial_state
],
)
self.db_pool.simple_upsert_many_txn(
txn,
table="event_to_state_groups",

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@ -1953,3 +1953,31 @@ class EventsWorkerStore(SQLBaseStore):
"get_event_id_for_timestamp_txn",
get_event_id_for_timestamp_txn,
)
@cachedList("is_partial_state_event", list_name="event_ids")
async def get_partial_state_events(
self, event_ids: Collection[str]
) -> Dict[str, bool]:
"""Checks which of the given events have partial state"""
result = await self.db_pool.simple_select_many_batch(
table="partial_state_events",
column="event_id",
iterable=event_ids,
retcols=["event_id"],
desc="get_partial_state_events",
)
# convert the result to a dict, to make @cachedList work
partial = {r["event_id"] for r in result}
return {e_id: e_id in partial for e_id in event_ids}
@cached()
async def is_partial_state_event(self, event_id: str) -> bool:
"""Checks if the given event has partial state"""
result = await self.db_pool.simple_select_one_onecol(
table="partial_state_events",
keyvalues={"event_id": event_id},
retcol="1",
allow_none=True,
desc="is_partial_state_event",
)
return result is not None

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@ -20,6 +20,7 @@ from typing import (
TYPE_CHECKING,
Any,
Awaitable,
Collection,
Dict,
List,
Optional,
@ -1543,6 +1544,42 @@ class RoomStore(RoomBackgroundUpdateStore, RoomWorkerStore):
lock=False,
)
async def store_partial_state_room(
self,
room_id: str,
servers: Collection[str],
) -> None:
"""Mark the given room as containing events with partial state
Args:
room_id: the ID of the room
servers: other servers known to be in the room
"""
await self.db_pool.runInteraction(
"store_partial_state_room",
self._store_partial_state_room_txn,
room_id,
servers,
)
@staticmethod
def _store_partial_state_room_txn(
txn: LoggingTransaction, room_id: str, servers: Collection[str]
) -> None:
DatabasePool.simple_insert_txn(
txn,
table="partial_state_rooms",
values={
"room_id": room_id,
},
)
DatabasePool.simple_insert_many_txn(
txn,
table="partial_state_rooms_servers",
keys=("room_id", "server_name"),
values=((room_id, s) for s in servers),
)
async def maybe_store_room_on_outlier_membership(
self, room_id: str, room_version: RoomVersion
) -> None:

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@ -0,0 +1,41 @@
/* Copyright 2022 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.
*/
-- rooms which we have done a partial-state-style join to
CREATE TABLE IF NOT EXISTS partial_state_rooms (
room_id TEXT PRIMARY KEY,
FOREIGN KEY(room_id) REFERENCES rooms(room_id)
);
-- a list of remote servers we believe are in the room
CREATE TABLE IF NOT EXISTS partial_state_rooms_servers (
room_id TEXT NOT NULL REFERENCES partial_state_rooms(room_id),
server_name TEXT NOT NULL,
UNIQUE(room_id, server_name)
);
-- a list of events with partial state. We can't store this in the `events` table
-- itself, because `events` is meant to be append-only.
CREATE TABLE IF NOT EXISTS partial_state_events (
-- the room_id is denormalised for efficient indexing (the canonical source is `events`)
room_id TEXT NOT NULL REFERENCES partial_state_rooms(room_id),
event_id TEXT NOT NULL REFERENCES events(event_id),
UNIQUE(event_id)
);
CREATE INDEX IF NOT EXISTS partial_state_events_room_id_idx
ON partial_state_events (room_id);

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@ -0,0 +1,72 @@
# Copyright 2022 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.
"""
This migration adds triggers to the partial_state_events tables to enforce uniqueness
Triggers cannot be expressed in .sql files, so we have to use a separate file.
"""
from synapse.storage.engines import BaseDatabaseEngine, PostgresEngine, Sqlite3Engine
from synapse.storage.types import Cursor
def run_create(cur: Cursor, database_engine: BaseDatabaseEngine, *args, **kwargs):
# complain if the room_id in partial_state_events doesn't match
# that in `events`. We already have a fk constraint which ensures that the event
# exists in `events`, so all we have to do is raise if there is a row with a
# matching stream_ordering but not a matching room_id.
if isinstance(database_engine, Sqlite3Engine):
cur.execute(
"""
CREATE TRIGGER IF NOT EXISTS partial_state_events_bad_room_id
BEFORE INSERT ON partial_state_events
FOR EACH ROW
BEGIN
SELECT RAISE(ABORT, 'Incorrect room_id in partial_state_events')
WHERE EXISTS (
SELECT 1 FROM events
WHERE events.event_id = NEW.event_id
AND events.room_id != NEW.room_id
);
END;
"""
)
elif isinstance(database_engine, PostgresEngine):
cur.execute(
"""
CREATE OR REPLACE FUNCTION check_partial_state_events() RETURNS trigger AS $BODY$
BEGIN
IF EXISTS (
SELECT 1 FROM events
WHERE events.event_id = NEW.event_id
AND events.room_id != NEW.room_id
) THEN
RAISE EXCEPTION 'Incorrect room_id in partial_state_events';
END IF;
RETURN NEW;
END;
$BODY$ LANGUAGE plpgsql;
"""
)
cur.execute(
"""
CREATE TRIGGER check_partial_state_events BEFORE INSERT OR UPDATE ON partial_state_events
FOR EACH ROW
EXECUTE PROCEDURE check_partial_state_events()
"""
)
else:
raise NotImplementedError("Unknown database engine")

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@ -11,7 +11,7 @@
# 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 typing import List, Optional
from typing import Collection, Dict, List, Optional
from unittest.mock import Mock
from twisted.internet import defer
@ -70,7 +70,7 @@ def create_event(
return event
class StateGroupStore:
class _DummyStore:
def __init__(self):
self._event_to_state_group = {}
self._group_to_state = {}
@ -105,6 +105,11 @@ class StateGroupStore:
if e_id in self._event_id_to_event
}
async def get_partial_state_events(
self, event_ids: Collection[str]
) -> Dict[str, bool]:
return {e: False for e in event_ids}
async def get_state_group_delta(self, name):
return None, None
@ -157,8 +162,8 @@ class Graph:
class StateTestCase(unittest.TestCase):
def setUp(self):
self.store = StateGroupStore()
storage = Mock(main=self.store, state=self.store)
self.dummy_store = _DummyStore()
storage = Mock(main=self.dummy_store, state=self.dummy_store)
hs = Mock(
spec_set=[
"config",
@ -173,7 +178,7 @@ class StateTestCase(unittest.TestCase):
]
)
hs.config = default_config("tesths", True)
hs.get_datastores.return_value = Mock(main=self.store)
hs.get_datastores.return_value = Mock(main=self.dummy_store)
hs.get_state_handler.return_value = None
hs.get_clock.return_value = MockClock()
hs.get_auth.return_value = Auth(hs)
@ -198,7 +203,7 @@ class StateTestCase(unittest.TestCase):
edges={"A": ["START"], "B": ["A"], "C": ["A"], "D": ["B", "C"]},
)
self.store.register_events(graph.walk())
self.dummy_store.register_events(graph.walk())
context_store: dict[str, EventContext] = {}
@ -206,7 +211,7 @@ class StateTestCase(unittest.TestCase):
context = yield defer.ensureDeferred(
self.state.compute_event_context(event)
)
self.store.register_event_context(event, context)
self.dummy_store.register_event_context(event, context)
context_store[event.event_id] = context
ctx_c = context_store["C"]
@ -242,7 +247,7 @@ class StateTestCase(unittest.TestCase):
edges={"A": ["START"], "B": ["A"], "C": ["A"], "D": ["B", "C"]},
)
self.store.register_events(graph.walk())
self.dummy_store.register_events(graph.walk())
context_store = {}
@ -250,7 +255,7 @@ class StateTestCase(unittest.TestCase):
context = yield defer.ensureDeferred(
self.state.compute_event_context(event)
)
self.store.register_event_context(event, context)
self.dummy_store.register_event_context(event, context)
context_store[event.event_id] = context
# C ends up winning the resolution between B and C
@ -300,7 +305,7 @@ class StateTestCase(unittest.TestCase):
edges={"A": ["START"], "B": ["A"], "C": ["B"], "D": ["B"], "E": ["C", "D"]},
)
self.store.register_events(graph.walk())
self.dummy_store.register_events(graph.walk())
context_store = {}
@ -308,7 +313,7 @@ class StateTestCase(unittest.TestCase):
context = yield defer.ensureDeferred(
self.state.compute_event_context(event)
)
self.store.register_event_context(event, context)
self.dummy_store.register_event_context(event, context)
context_store[event.event_id] = context
# C ends up winning the resolution between C and D because bans win over other
@ -375,7 +380,7 @@ class StateTestCase(unittest.TestCase):
self._add_depths(nodes, edges)
graph = Graph(nodes, edges)
self.store.register_events(graph.walk())
self.dummy_store.register_events(graph.walk())
context_store = {}
@ -383,7 +388,7 @@ class StateTestCase(unittest.TestCase):
context = yield defer.ensureDeferred(
self.state.compute_event_context(event)
)
self.store.register_event_context(event, context)
self.dummy_store.register_event_context(event, context)
context_store[event.event_id] = context
# B ends up winning the resolution between B and C because power levels
@ -476,7 +481,7 @@ class StateTestCase(unittest.TestCase):
]
group_name = yield defer.ensureDeferred(
self.store.store_state_group(
self.dummy_store.store_state_group(
prev_event_id,
event.room_id,
None,
@ -484,7 +489,7 @@ class StateTestCase(unittest.TestCase):
{(e.type, e.state_key): e.event_id for e in old_state},
)
)
self.store.register_event_id_state_group(prev_event_id, group_name)
self.dummy_store.register_event_id_state_group(prev_event_id, group_name)
context = yield defer.ensureDeferred(self.state.compute_event_context(event))
@ -510,7 +515,7 @@ class StateTestCase(unittest.TestCase):
]
group_name = yield defer.ensureDeferred(
self.store.store_state_group(
self.dummy_store.store_state_group(
prev_event_id,
event.room_id,
None,
@ -518,7 +523,7 @@ class StateTestCase(unittest.TestCase):
{(e.type, e.state_key): e.event_id for e in old_state},
)
)
self.store.register_event_id_state_group(prev_event_id, group_name)
self.dummy_store.register_event_id_state_group(prev_event_id, group_name)
context = yield defer.ensureDeferred(self.state.compute_event_context(event))
@ -554,8 +559,8 @@ class StateTestCase(unittest.TestCase):
create_event(type="test4", state_key=""),
]
self.store.register_events(old_state_1)
self.store.register_events(old_state_2)
self.dummy_store.register_events(old_state_1)
self.dummy_store.register_events(old_state_2)
context = yield self._get_context(
event, prev_event_id1, old_state_1, prev_event_id2, old_state_2
@ -594,10 +599,10 @@ class StateTestCase(unittest.TestCase):
create_event(type="test4", state_key=""),
]
store = StateGroupStore()
store = _DummyStore()
store.register_events(old_state_1)
store.register_events(old_state_2)
self.store.get_events = store.get_events
self.dummy_store.get_events = store.get_events
context = yield self._get_context(
event, prev_event_id1, old_state_1, prev_event_id2, old_state_2
@ -649,10 +654,10 @@ class StateTestCase(unittest.TestCase):
create_event(type="test1", state_key="1", depth=2),
]
store = StateGroupStore()
store = _DummyStore()
store.register_events(old_state_1)
store.register_events(old_state_2)
self.store.get_events = store.get_events
self.dummy_store.get_events = store.get_events
context = yield self._get_context(
event, prev_event_id1, old_state_1, prev_event_id2, old_state_2
@ -695,7 +700,7 @@ class StateTestCase(unittest.TestCase):
self, event, prev_event_id_1, old_state_1, prev_event_id_2, old_state_2
):
sg1 = yield defer.ensureDeferred(
self.store.store_state_group(
self.dummy_store.store_state_group(
prev_event_id_1,
event.room_id,
None,
@ -703,10 +708,10 @@ class StateTestCase(unittest.TestCase):
{(e.type, e.state_key): e.event_id for e in old_state_1},
)
)
self.store.register_event_id_state_group(prev_event_id_1, sg1)
self.dummy_store.register_event_id_state_group(prev_event_id_1, sg1)
sg2 = yield defer.ensureDeferred(
self.store.store_state_group(
self.dummy_store.store_state_group(
prev_event_id_2,
event.room_id,
None,
@ -714,7 +719,7 @@ class StateTestCase(unittest.TestCase):
{(e.type, e.state_key): e.event_id for e in old_state_2},
)
)
self.store.register_event_id_state_group(prev_event_id_2, sg2)
self.dummy_store.register_event_id_state_group(prev_event_id_2, sg2)
result = yield defer.ensureDeferred(self.state.compute_event_context(event))
return result