From 0676311d3830b74b84cf4c902dee3042a9bd43b0 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 13 Sep 2023 11:45:33 +0100
Subject: [PATCH 1/2] Don't schedule a async task on every sync
---
synapse/handlers/sync.py | 37 ++++++++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 0ccd7d250c4b..f1f19666d7cf 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -362,21 +362,36 @@ async def _wait_for_sync_for_user(
# (since we now know that the device has received them)
if since_token is not None:
since_stream_id = since_token.to_device_key
- # Delete device messages asynchronously and in batches using the task scheduler
- await self._task_scheduler.schedule_task(
- DELETE_DEVICE_MSGS_TASK_NAME,
- resource_id=sync_config.device_id,
- params={
- "user_id": sync_config.user.to_string(),
- "device_id": sync_config.device_id,
- "up_to_stream_id": since_stream_id,
- },
+ # Fast path: delete a limited number of to-device messages up front.
+ # We do this to avoid the overhead of scheduling a task for every
+ # sync.
+ device_deletion_limit = 100
+ deleted = await self.store.delete_messages_for_device(
+ sync_config.user.to_string(),
+ sync_config.device_id,
+ since_stream_id,
+ limit=device_deletion_limit,
)
logger.debug(
- "Deletion of to-device messages up to %d scheduled",
- since_stream_id,
+ "Deleted %d to-device messages up to %d", deleted, since_stream_id
)
+ # If we hit the limit, schedule a background task to delete the rest.
+ if deleted >= device_deletion_limit:
+ await self._task_scheduler.schedule_task(
+ DELETE_DEVICE_MSGS_TASK_NAME,
+ resource_id=sync_config.device_id,
+ params={
+ "user_id": sync_config.user.to_string(),
+ "device_id": sync_config.device_id,
+ "up_to_stream_id": since_stream_id,
+ },
+ )
+ logger.debug(
+ "Deletion of to-device messages up to %d scheduled",
+ since_stream_id,
+ )
+
if timeout == 0 or since_token is None or full_state:
# we are going to return immediately, so don't bother calling
# notifier.wait_for_events.
From 183e91b8ed216c7a7662a29c00c7bd71286a8fcb Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 13 Sep 2023 11:46:38 +0100
Subject: [PATCH 2/2] Newsfile
---
changelog.d/16312.misc | 1 +
1 file changed, 1 insertion(+)
create mode 100644 changelog.d/16312.misc
diff --git a/changelog.d/16312.misc b/changelog.d/16312.misc
new file mode 100644
index 000000000000..4f266c1fb029
--- /dev/null
+++ b/changelog.d/16312.misc
@@ -0,0 +1 @@
+Delete device messages asynchronously and in staged batches using the task scheduler.