Comment 1 for bug 1430641

Some idea cross my mind, I saw a test case "test_graceful_fetch_on_non_rows" in sqlalchemy/test/sql/test_query.py as below,
I am guessing whether in your cinder db there are records in table "volumes". Logs you posted looks like querying volumes in volume_get_all, this happens when cinder audit running periodically. Maybe when there are no volumes, we will see such exception logs.

def test_graceful_fetch_on_non_rows(self):
"""test that calling fetchone() etc. on a result that doesn't
        return rows fails gracefully.
"""
        conn = testing.db.connect()
        for meth in ('fetchone', 'fetchall', 'first', 'scalar', 'fetchmany'):
            trans = conn.begin()
            result = conn.execute(users.insert(), user_id=1)
            assert_raises_message(
                exc.ResourceClosedError,
                "This result object does not return rows. "
                "It has been closed automatically.",
                getattr(result, meth),
            )
            trans.rollback()