From https://bugzilla.redhat.com/show_bug.cgi?id=2280606:

Description of problem:
One of our customers faced upstream bug https://bugs.launchpad.net/nova/+bug/1983188 in his RHOSP 16.2 deployment when running the following command against nova DB with 18 GBs of records in shadow_instances table:

1. podman exec -it nova_api_cron bash -c "nova-manage db purge --verbose --all --all-cells"
   An error has occurred:
   Traceback (most recent call last):
   File "/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 761, in _commit_impl
   self.engine.dialect.do_commit(self.connection)
   File "/usr/lib64/python3.6/site-packages/sqlalchemy/dialects/mysql/base.py", line 2215, in do_commit
   dbapi_connection.commit()
   File "/usr/lib/python3.6/site-packages/pymysql/connections.py", line 422, in commit
   self._read_ok_packet()
   File "/usr/lib/python3.6/site-packages/pymysql/connections.py", line 396, in _read_ok_packet
   pkt = self._read_packet()
   File "/usr/lib/python3.6/site-packages/pymysql/connections.py", line 676, in _read_packet
   packet.raise_for_error()
   File "/usr/lib/python3.6/site-packages/pymysql/protocol.py", line 223, in raise_for_error
   err.raise_mysql_exception(self._data)
   File "/usr/lib/python3.6/site-packages/pymysql/err.py", line 107, in raise_mysql_exception
   raise errorclass(errno, errval)
   pymysql.err.OperationalError: (1180, 'Got error 90 "Message too long" during COMMIT')

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/lib/python3.6/site-packages/nova/cmd/manage.py", line 3314, in main
ret = fn(*fn_args, **fn_kwargs)
File "/usr/lib/python3.6/site-packages/nova/cmd/manage.py", line 747, in purge
status_fn=status)
File "/usr/lib/python3.6/site-packages/nova/db/sqlalchemy/api.py", line 5817, in purge_shadow_tables
deleted = conn.execute(delete)
File "/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 988, in execute
return meth(self, multiparams, params)
File "/usr/lib64/python3.6/site-packages/sqlalchemy/sql/elements.py", line 287, in _execute_on_connection
return connection._execute_clauseelement(self, multiparams, params)
File "/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 1107, in _execute_clauseelement
distilled_params,
File "/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 1272, in _execute_context
self._root._commit_impl(autocommit=True)
File "/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 763, in _commit_impl
self._handle_dbapi_exception(e, None, None, None, None)
File "/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 1464, in _handle_dbapi_exception
util.raise_from_cause(newraise, exc_info)
File "/usr/lib64/python3.6/site-packages/sqlalchemy/util/compat.py", line 383, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb, cause=cause)
File "/usr/lib64/python3.6/site-packages/sqlalchemy/util/compat.py", line 128, in reraise
raise value.with_traceback(tb)
File "/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 761, in _commit_impl
self.engine.dialect.do_commit(self.connection)
File "/usr/lib64/python3.6/site-packages/sqlalchemy/dialects/mysql/base.py", line 2215, in do_commit
dbapi_connection.commit()
File "/usr/lib/python3.6/site-packages/pymysql/connections.py", line 422, in commit
self._read_ok_packet()
File "/usr/lib/python3.6/site-packages/pymysql/connections.py", line 396, in _read_ok_packet
pkt = self._read_packet()
File "/usr/lib/python3.6/site-packages/pymysql/connections.py", line 676, in _read_packet
packet.raise_for_error()
File "/usr/lib/python3.6/site-packages/pymysql/protocol.py", line 223, in raise_for_error
err.raise_mysql_exception(self._data)
File "/usr/lib/python3.6/site-packages/pymysql/err.py", line 107, in raise_mysql_exception
raise errorclass(errno, errval)
sqlalchemy.exc.OperationalError: (pymysql.err.OperationalError) (1180, 'Got error 90 "Message too long" during COMMIT')
(Background on this error at: http://sqlalche.me/e/e3q8)

I understand that it is not going to be fixed in RHOSP 16.2, but kindly ask engineering to consider fixing it in RHOSP 17.1.

Version-Release number of selected component (if applicable):
RHOSP 16.2 +

How reproducible: see description

Actual results: nova-manage fails to purge archived entries if their number is too big

Expected results: nova-manage successfully drops archived entries no matter how big their number is