Queens Series Release Notes¶

Repaired the “synchronous_reader” modifier of enginefacade so that it refers to the “writer” engine when set to True, thereby allowing “synchronous” behavior with the writer. When set to False, this is “asynchronous”, so this should be associated with the async engines. The flag had the reverse behavior previously.

PyMySQL is a default MySQL DB API driver for oslo.db, as well as for the whole OpenStack. So far it was possible to use MySQL-python as an alternative DB API driver. This driver is no longer being tested in this release, hence it should be considered unsupported. Please switch to PyMySQL, which is an adequate replacement. Refer to https://wiki.openstack.org/wiki/PyMySQL_evaluation for details.

The configuration option idle_timeout is now deprecated and has been renamed to connection_recycle_time, including within the main oslo.db options, as well as in the keyword arguments to engines.create_engine(), enginefacade.configure() and enginefacade.configure_defaults(). The new name more accurately describes what this option does, in that it is not directly related to the “idle” time of the connection itself, nor is the connection disconnected at any specific time. It refers to a rule stating that any connection which has been present more than N seconds as a member of the connection pool will be automatically discarded and replaced the next time it is checked out from the pool.