Reduce DB load of /sync when using presence (#12885)

While the query was fast, we were calling it *a lot*.
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Erik Johnston 2022-05-31 14:01:05 +01:00 committed by GitHub
parent 5e17922ef7
commit c8684e6792
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2 changed files with 49 additions and 27 deletions

1
changelog.d/12885.misc Normal file
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@ -0,0 +1 @@
Reduce database load of `/sync` when presence is enabled.

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@ -12,7 +12,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Tuple, cast
from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Optional, Tuple, cast
from synapse.api.presence import PresenceState, UserPresenceState
from synapse.replication.tcp.streams import PresenceStream
@ -22,6 +22,7 @@ from synapse.storage.database import (
LoggingDatabaseConnection,
LoggingTransaction,
)
from synapse.storage.databases.main.cache import CacheInvalidationWorkerStore
from synapse.storage.engines import PostgresEngine
from synapse.storage.types import Connection
from synapse.storage.util.id_generators import (
@ -56,7 +57,7 @@ class PresenceBackgroundUpdateStore(SQLBaseStore):
)
class PresenceStore(PresenceBackgroundUpdateStore):
class PresenceStore(PresenceBackgroundUpdateStore, CacheInvalidationWorkerStore):
def __init__(
self,
database: DatabasePool,
@ -281,20 +282,30 @@ class PresenceStore(PresenceBackgroundUpdateStore):
True if the user should have full presence sent to them, False otherwise.
"""
def _should_user_receive_full_presence_with_token_txn(
txn: LoggingTransaction,
) -> bool:
sql = """
SELECT 1 FROM users_to_send_full_presence_to
WHERE user_id = ?
AND presence_stream_id >= ?
"""
txn.execute(sql, (user_id, from_token))
return bool(txn.fetchone())
token = await self._get_full_presence_stream_token_for_user(user_id)
if token is None:
return False
return await self.db_pool.runInteraction(
"should_user_receive_full_presence_with_token",
_should_user_receive_full_presence_with_token_txn,
return from_token <= token
@cached()
async def _get_full_presence_stream_token_for_user(
self, user_id: str
) -> Optional[int]:
"""Get the presence token corresponding to the last full presence update
for this user.
If the user presents a sync token with a presence stream token at least
as old as the result, then we need to send them a full presence update.
If this user has never needed a full presence update, returns `None`.
"""
return await self.db_pool.simple_select_one_onecol(
table="users_to_send_full_presence_to",
keyvalues={"user_id": user_id},
retcol="presence_stream_id",
allow_none=True,
desc="_get_full_presence_stream_token_for_user",
)
async def add_users_to_send_full_presence_to(self, user_ids: Iterable[str]) -> None:
@ -307,18 +318,28 @@ class PresenceStore(PresenceBackgroundUpdateStore):
# Add user entries to the table, updating the presence_stream_id column if the user already
# exists in the table.
presence_stream_id = self._presence_id_gen.get_current_token()
await self.db_pool.simple_upsert_many(
table="users_to_send_full_presence_to",
key_names=("user_id",),
key_values=[(user_id,) for user_id in user_ids],
value_names=("presence_stream_id",),
# We save the current presence stream ID token along with the user ID entry so
# that when a user /sync's, even if they syncing multiple times across separate
# devices at different times, each device will receive full presence once - when
# the presence stream ID in their sync token is less than the one in the table
# for their user ID.
value_values=[(presence_stream_id,) for _ in user_ids],
desc="add_users_to_send_full_presence_to",
def _add_users_to_send_full_presence_to(txn: LoggingTransaction) -> None:
self.db_pool.simple_upsert_many_txn(
txn,
table="users_to_send_full_presence_to",
key_names=("user_id",),
key_values=[(user_id,) for user_id in user_ids],
value_names=("presence_stream_id",),
# We save the current presence stream ID token along with the user ID entry so
# that when a user /sync's, even if they syncing multiple times across separate
# devices at different times, each device will receive full presence once - when
# the presence stream ID in their sync token is less than the one in the table
# for their user ID.
value_values=[(presence_stream_id,) for _ in user_ids],
)
for user_id in user_ids:
self._invalidate_cache_and_stream(
txn, self._get_full_presence_stream_token_for_user, (user_id,)
)
return await self.db_pool.runInteraction(
"add_users_to_send_full_presence_to", _add_users_to_send_full_presence_to
)
async def get_presence_for_all_users(