diff --git a/synapse/storage/stats.py b/synapse/storage/stats.py
index a372f35eae..cebe4cbc57 100644
--- a/synapse/storage/stats.py
+++ b/synapse/storage/stats.py
@@ -183,6 +183,14 @@ class StatsStore(StateDeltasStore):
field_sqls.append("completed_delta_stream_id = ?")
field_values.append(complete_with_stream_id)
+ # update current row, but only if it is either:
+ # - dirty and complete but not old
+ # If it is old, we should old-collect it first and retry.
+ # - dirty and incomplete
+ # Incomplete rows can't be old-collected (as this would commit
+ # false statistics into the _historical table).
+ # Instead, their `end_ts` is extended, whilst we wait for them to
+ # become complete at the hand of the stats regenerator.
sql = (
"UPDATE %s_current SET end_ts = ?, %s"
" WHERE (end_ts IS NOT NULL AND (end_ts >= ? OR completed_delta_stream_id IS NULL))"
@@ -209,6 +217,8 @@ class StatsStore(StateDeltasStore):
)
if current_row is None:
+ # Failure reason: There is no row.
+ # Solution:
# we need to insert a row! (insert a dirty, incomplete row)
insertee = {
id_col: stats_id,
@@ -234,7 +244,9 @@ class StatsStore(StateDeltasStore):
self._simple_insert_txn(txn, table + "_current", insertee)
elif current_row["end_ts"] is None:
- # update the row, including start_ts
+ # Failure reason: The row is not dirty.
+ # Solution:
+ # update the row, including `start_ts`, to make it dirty.
sql = (
"UPDATE %s_current SET start_ts = ?, end_ts = ?, %s"
" WHERE end_ts IS NULL AND %s = ?"
@@ -254,5 +266,6 @@ class StatsStore(StateDeltasStore):
)
elif current_row["end_ts"] < end_ts:
- # we need to perform old collection first
+ # Failure reason: The row is complete and old.
+ # Solution: We need to perform old collection first
raise OldCollectionRequired()
|
