Speed up get_unread_event_push_actions_by_room (#13005)

Fixes #11887 hopefully.

The core change here is that `event_push_summary` now holds a summary of counts up until a much more recent point, meaning that the range of rows we need to count in `event_push_actions` is much smaller.

This needs two major changes:
1. When we get a receipt we need to recalculate `event_push_summary` rather than just delete it
2. The logic for deleting `event_push_actions` is now divorced from calculating `event_push_summary`.

In future it would be good to calculate `event_push_summary` while we persist a new event (it should just be a case of adding one to the relevant rows in `event_push_summary`), as that will further simplify the get counts logic and remove the need for us to periodically update `event_push_summary` in a background job.

changelog.d/13005.misc

@@ -0,0 +1 @@
+Reduce DB usage of `/sync` when a large number of unread messages have recently been sent in a room.

synapse/_scripts/synapse_port_db.py

@@ -58,6 +58,9 @@
 from synapse.storage.databases.main.deviceinbox import DeviceInboxBackgroundUpdateStore
 from synapse.storage.databases.main.devices import DeviceBackgroundUpdateStore
 from synapse.storage.databases.main.end_to_end_keys import EndToEndKeyBackgroundStore
+from synapse.storage.databases.main.event_push_actions import (
+    EventPushActionsWorkerStore,
+)
 from synapse.storage.databases.main.events_bg_updates import (
     EventsBackgroundUpdatesStore,
 )
@@ -199,6 +202,7 @@
 
 
 class Store(
+    EventPushActionsWorkerStore,
     ClientIpBackgroundUpdateStore,
     DeviceInboxBackgroundUpdateStore,
     DeviceBackgroundUpdateStore,

synapse/handlers/sync.py

@@ -18,7 +18,7 @@
 import attr
 from prometheus_client import Counter
 
-from synapse.api.constants import EventTypes, Membership, ReceiptTypes
+from synapse.api.constants import EventTypes, Membership
 from synapse.api.filtering import FilterCollection
 from synapse.api.presence import UserPresenceState
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
@@ -1054,14 +1054,10 @@ async def unread_notifs_for_room_id(
         self, room_id: str, sync_config: SyncConfig
     ) -> NotifCounts:
         with Measure(self.clock, "unread_notifs_for_room_id"):
-            last_unread_event_id = await self.store.get_last_receipt_event_id_for_user(
-                user_id=sync_config.user.to_string(),
-                room_id=room_id,
-                receipt_types=(ReceiptTypes.READ, ReceiptTypes.READ_PRIVATE),
-            )
 
             return await self.store.get_unread_event_push_actions_by_room_for_user(
-                room_id, sync_config.user.to_string(), last_unread_event_id
+                room_id,
+                sync_config.user.to_string(),
             )
 
     async def generate_sync_result(

synapse/push/push_tools.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 from typing import Dict
 
-from synapse.api.constants import ReceiptTypes
 from synapse.events import EventBase
 from synapse.push.presentable_names import calculate_room_name, name_from_member_event
 from synapse.storage.controllers import StorageControllers
@@ -24,30 +23,24 @@ async def get_badge_count(store: DataStore, user_id: str, group_by_room: bool) -
     invites = await store.get_invited_rooms_for_local_user(user_id)
     joins = await store.get_rooms_for_user(user_id)
 
-    my_receipts_by_room = await store.get_receipts_for_user(
-        user_id, (ReceiptTypes.READ, ReceiptTypes.READ_PRIVATE)
-    )
-
     badge = len(invites)
 
     for room_id in joins:
-        if room_id in my_receipts_by_room:
-            last_unread_event_id = my_receipts_by_room[room_id]
-
-            notifs = await (
-                store.get_unread_event_push_actions_by_room_for_user(
-                    room_id, user_id, last_unread_event_id
-                )
+        notifs = await (
+            store.get_unread_event_push_actions_by_room_for_user(
+                room_id,
+                user_id,
             )
-            if notifs.notify_count == 0:
-                continue
+        )
+        if notifs.notify_count == 0:
+            continue
 
-            if group_by_room:
-                # return one badge count per conversation
-                badge += 1
-            else:
-                # increment the badge count by the number of unread messages in the room
-                badge += notifs.notify_count
+        if group_by_room:
+            # return one badge count per conversation
+            badge += 1
+        else:
+            # increment the badge count by the number of unread messages in the room
+            badge += notifs.notify_count
     return badge
 
 

synapse/storage/database.py

@@ -92,6 +92,7 @@
     "event_search": "event_search_event_id_idx",
     "local_media_repository_thumbnails": "local_media_repository_thumbnails_method_idx",
     "remote_media_cache_thumbnails": "remote_media_repository_thumbnails_method_idx",
+    "event_push_summary": "event_push_summary_unique_index",
 }
 
 

synapse/storage/databases/main/__init__.py

@@ -104,13 +104,14 @@ class DataStore(
     PusherStore,
     PushRuleStore,
     ApplicationServiceTransactionStore,
+    EventPushActionsStore,
+    ServerMetricsStore,
     ReceiptsStore,
     EndToEndKeyStore,
     EndToEndRoomKeyStore,
     SearchStore,
     TagsStore,
     AccountDataStore,
-    EventPushActionsStore,
     OpenIdStore,
     ClientIpWorkerStore,
     DeviceStore,
@@ -124,7 +125,6 @@ class DataStore(
     UIAuthStore,
     EventForwardExtremitiesStore,
     CacheInvalidationWorkerStore,
-    ServerMetricsStore,
     LockStore,
     SessionStore,
 ):