Unreleased Release Notes

17.4.0-8

New Features

• Add a new parameter named synchronous_reader for sqlalchemy backend so an operator can choose from configuration file if reader context should be synchronous or not. When synchronous_reader is set to True (the default), a database reader context will guarantee it can read data from a writer context by reusing the same connection parameter, thus ignoring the slave_connection parameter. When synchronous_reader is set to False, a database reader context works the same as an async_reader and will select the slave_connection parameter to connect to the database if present. When setting this parameter to False, make sure your cluster lag is not a problem or set mysql_wsrep_sync_wait accordingly.

Upgrade Notes

• The oslo_db.sqlalchemy.enginefacade.LegacyEngineFacade class and related helpers, namely _TransactionFactory.get_legacy_facade, _TransactionContextManager.get_legacy_facade and get_legacy_facade from the same module, have all been removed. The LegacyEngineFacade class has been deprecated since 1.12.0 in favour of using the oslo_db.sqlalchemy.enginefacade module directly.

• Support for Python 3.9 has been removed. Now the minimum python version supported is 3.10.