diff options
| -rw-r--r-- | changelog.d/16643.misc | 1 | ||||
| -rw-r--r-- | synapse/handlers/device.py | 8 | ||||
| -rw-r--r-- | synapse/storage/databases/main/deviceinbox.py | 106 | ||||
| -rw-r--r-- | synapse/util/task_scheduler.py | 2 |
4 files changed, 88 insertions, 29 deletions
diff --git a/changelog.d/16643.misc b/changelog.d/16643.misc new file mode 100644 index 0000000000..cc0cf0901f --- /dev/null +++ b/changelog.d/16643.misc @@ -0,0 +1 @@ +Speed up deleting of device messages when deleting a device. diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py index 93472d0117..1af6d77545 100644 --- a/synapse/handlers/device.py +++ b/synapse/handlers/device.py @@ -396,15 +396,17 @@ class DeviceWorkerHandler: up_to_stream_id = task.params["up_to_stream_id"] # Delete the messages in batches to avoid too much DB load. + from_stream_id = None while True: - res = await self.store.delete_messages_for_device( + from_stream_id, _ = await self.store.delete_messages_for_device_between( user_id=user_id, device_id=device_id, - up_to_stream_id=up_to_stream_id, + from_stream_id=from_stream_id, + to_stream_id=up_to_stream_id, limit=DeviceHandler.DEVICE_MSGS_DELETE_BATCH_LIMIT, ) - if res < DeviceHandler.DEVICE_MSGS_DELETE_BATCH_LIMIT: + if from_stream_id is None: return TaskStatus.COMPLETE, None, None await self.clock.sleep(DeviceHandler.DEVICE_MSGS_DELETE_SLEEP_MS / 1000.0) diff --git a/synapse/storage/databases/main/deviceinbox.py b/synapse/storage/databases/main/deviceinbox.py index 3e7425d4a6..02dddd1da4 100644 --- a/synapse/storage/databases/main/deviceinbox.py +++ b/synapse/storage/databases/main/deviceinbox.py @@ -450,14 +450,12 @@ class DeviceInboxWorkerStore(SQLBaseStore): user_id: str, device_id: Optional[str], up_to_stream_id: int, - limit: Optional[int] = None, ) -> int: """ Args: user_id: The recipient user_id. device_id: The recipient device_id. up_to_stream_id: Where to delete messages up to. - limit: maximum number of messages to delete Returns: The number of messages deleted. @@ -478,32 +476,22 @@ class DeviceInboxWorkerStore(SQLBaseStore): log_kv({"message": "No changes in cache since last check"}) return 0 - def delete_messages_for_device_txn(txn: LoggingTransaction) -> int: - limit_statement = "" if limit is None else f"LIMIT {limit}" - sql = f""" - DELETE FROM device_inbox WHERE user_id = ? AND device_id = ? AND stream_id <= ( - SELECT MAX(stream_id) FROM ( - SELECT stream_id FROM device_inbox - WHERE user_id = ? AND device_id = ? AND stream_id <= ? - ORDER BY stream_id - {limit_statement} - ) AS q1 - ) - """ - txn.execute(sql, (user_id, device_id, user_id, device_id, up_to_stream_id)) - return txn.rowcount - - count = await self.db_pool.runInteraction( - "delete_messages_for_device", delete_messages_for_device_txn - ) + from_stream_id = None + count = 0 + while True: + from_stream_id, loop_count = await self.delete_messages_for_device_between( + user_id, + device_id, + from_stream_id=from_stream_id, + to_stream_id=up_to_stream_id, + limit=1000, + ) + count += loop_count + if from_stream_id is None: + break log_kv({"message": f"deleted {count} messages for device", "count": count}) - # In this case we don't know if we hit the limit or the delete is complete - # so let's not update the cache. - if count == limit: - return count - # Update the cache, ensuring that we only ever increase the value updated_last_deleted_stream_id = self._last_device_delete_cache.get( (user_id, device_id), 0 @@ -515,6 +503,74 @@ class DeviceInboxWorkerStore(SQLBaseStore): return count @trace + async def delete_messages_for_device_between( + self, + user_id: str, + device_id: Optional[str], + from_stream_id: Optional[int], + to_stream_id: int, + limit: int, + ) -> Tuple[Optional[int], int]: + """Delete N device messages between the stream IDs, returning the + highest stream ID deleted (or None if all messages in the range have + been deleted) and the number of messages deleted. + + This is more efficient than `delete_messages_for_device` when calling in + a loop to batch delete messages. + """ + + # Keeping track of a lower bound of stream ID where we've deleted + # everything below makes the queries much faster. Otherwise, every time + # we scan for rows to delete we'd re-scan across all the rows that have + # previously deleted (until the next table VACUUM). + + if from_stream_id is None: + # Minimum device stream ID is 1. + from_stream_id = 0 + + def delete_messages_for_device_between_txn( + txn: LoggingTransaction, + ) -> Tuple[Optional[int], int]: + txn.execute( + """ + SELECT MAX(stream_id) FROM ( + SELECT stream_id FROM device_inbox + WHERE user_id = ? AND device_id = ? + AND ? < stream_id AND stream_id <= ? + ORDER BY stream_id + LIMIT ? + ) AS d + """, + (user_id, device_id, from_stream_id, to_stream_id, limit), + ) + row = txn.fetchone() + if row is None or row[0] is None: + return None, 0 + + (max_stream_id,) = row + + txn.execute( + """ + DELETE FROM device_inbox + WHERE user_id = ? AND device_id = ? + AND ? < stream_id AND stream_id <= ? + """, + (user_id, device_id, from_stream_id, max_stream_id), + ) + + num_deleted = txn.rowcount + if num_deleted < limit: + return None, num_deleted + + return max_stream_id, num_deleted + + return await self.db_pool.runInteraction( + "delete_messages_for_device_between", + delete_messages_for_device_between_txn, + db_autocommit=True, # We don't need to run in a transaction + ) + + @trace async def get_new_device_msgs_for_remote( self, destination: str, last_stream_id: int, current_stream_id: int, limit: int ) -> Tuple[List[JsonDict], int]: diff --git a/synapse/util/task_scheduler.py b/synapse/util/task_scheduler.py index caf13b3474..29c561e555 100644 --- a/synapse/util/task_scheduler.py +++ b/synapse/util/task_scheduler.py @@ -193,7 +193,7 @@ class TaskScheduler: result: Optional[JsonMapping] = None, error: Optional[str] = None, ) -> bool: - """Update some task associated values. This is exposed publically so it can + """Update some task associated values. This is exposed publicly so it can be used inside task functions, mainly to update the result and be able to resume a task at a specific step after a restart of synapse. |