Automatically apply SQL for inconsistent sequence (#17305)
Rather than forcing the server operator to apply the SQL manually.
This should be safe, as there should be only one writer for these
sequences.
1 files changed, 15 insertions, 22 deletions
diff --git a/synapse/storage/util/sequence.py b/synapse/storage/util/sequence.py
index f57e7ec41c..c4c0602b28 100644
--- a/synapse/storage/util/sequence.py
+++ b/synapse/storage/util/sequence.py
@@ -36,21 +36,6 @@ if TYPE_CHECKING:
logger = logging.getLogger(__name__)
-_INCONSISTENT_SEQUENCE_ERROR = """
-Postgres sequence '%(seq)s' is inconsistent with associated
-table '%(table)s'. This can happen if Synapse has been downgraded and
-then upgraded again, or due to a bad migration.
-
-To fix this error, shut down Synapse (including any and all workers)
-and run the following SQL:
-
- SELECT setval('%(seq)s', (
- %(max_id_sql)s
- ));
-
-See docs/postgres.md for more information.
-"""
-
_INCONSISTENT_STREAM_ERROR = """
Postgres sequence '%(seq)s' is inconsistent with associated stream position
of '%(stream_name)s' in the 'stream_positions' table.
@@ -169,25 +154,33 @@ class PostgresSequenceGenerator(SequenceGenerator):
if row:
max_in_stream_positions = row[0]
- txn.close()
-
# If `is_called` is False then `last_value` is actually the value that
# will be generated next, so we decrement to get the true "last value".
if not is_called:
last_value -= 1
if max_stream_id > last_value:
+ # The sequence is lagging behind the tables. This is probably due to
+ # rolling back to a version before the sequence was used and then
+ # forwards again. We resolve this by setting the sequence to the
+ # right value.
logger.warning(
- "Postgres sequence %s is behind table %s: %d < %d",
+ "Postgres sequence %s is behind table %s: %d < %d. Updating sequence.",
self._sequence_name,
table,
last_value,
max_stream_id,
)
- raise IncorrectDatabaseSetup(
- _INCONSISTENT_SEQUENCE_ERROR
- % {"seq": self._sequence_name, "table": table, "max_id_sql": table_sql}
- )
+
+ sql = f"""
+ SELECT setval('{self._sequence_name}', GREATEST(
+ (SELECT last_value FROM {self._sequence_name}),
+ ({table_sql})
+ ));
+ """
+ txn.execute(sql)
+
+ txn.close()
# If we have values in the stream positions table then they have to be
# less than or equal to `last_value`
|
