Bug Fixes¶

• In mysql 8.0.19, duplicate key error information is extended toinclude the table name of the key. Previously, duplicate key errorinformation included only the key value and key name.This extends capabilities to handle changes in duplicate key errorinformation with newer mysql version since 8.0.19.

Upgrade Notes¶

• Support for Python 2.7 has been dropped. The minimum version of Python nowsupported is Python 3.6.

Bug Fixes¶

• Removed deprecated database optionmin_pool_size.

  This option had no effect and was deprecated in Rocky. For moreinformation see bug1764786.

New Features¶

• Added new.is_started boolean flag to enginefacade context managerand factory objects, so that double-configure scenarios can be preventedby calling code. Additionally, theTypeError raised when configureis called after the factory is started is now a specific subclassenginefacade.AlreadyStartedError.

New Features¶

• Added new option connection_parameters which allows SQLAlchemy queryparameters to be stated separately from the URL itself, to allowURL-persistence schemes like Nova cells to use controller-localquery parameters that aren’t broadcast to all other servers.

Bug Fixes¶

• Repaired the “synchronous_reader” modifier of enginefacade so that itrefers 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.

Deprecation Notes¶

• PyMySQL is a default MySQL DB API driver for oslo.db, as well as for the wholeOpenStack. 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 consideredunsupported. Please switch to PyMySQL, which is an adequate replacement. Refer tohttps://wiki.openstack.org/wiki/PyMySQL_evaluation for details.

Deprecation Notes¶

• The configuration optionidle_timeout is now deprecated and has beenrenamed toconnection_recycle_time, including within the main oslo.dboptions, as well as in the keyword arguments toengines.create_engine(),enginefacade.configure() andenginefacade.configure_defaults(). The new name more accuratelydescribes what this option does, in that it is not directly related to the“idle” time of the connection itself, nor is the connection disconnected atany specific time. It refers to a rule stating that any connection whichhas been present more than N seconds as a member of the connection poolwill be automatically discarded and replaced the next time it is checkedout from the pool.

Upgrade Notes¶

• oslo.db now logs a warning when the connection URL does notexplicitly mention a driver. The default driver is still used, butin some cases, such as MySQL, the default is incompatible with theconcurrency library eventlet.

• It is strongly recommended to use thePyMySQL driver when connectingto a MySQL-compatible database to ensure the best compatibilitywith the concurrency library eventlet. To use PyMySQL, ensure theconnection URL is specified withmysql+pymysql:// as thescheme.

Upgrade Notes¶

• The configuration optionsqlite_db is removed. Pease use configuration optionconnection orslave_connection to connect to the database.

Deprecation Notes¶

• classInsertFromSelect from moduleoslo_db.sqlalchemy.utils is deprecated in favor ofsqlalchemy.sql.expression.Insert.from_select() method of Insert expression, that is available in SQLAlchemy versions 1.0.0 and newer

• base test classes fromoslo_db.sqlalchemy.test_base are deprecated in favor of new fixtures introduced inoslo_db.sqlalchemy.test_fixtures module

Bug Fixes¶

• Decoratoroslo_db.api.wrap_db_retry now defaults to 10 retries. Previously the number of attempts was 0, and users had to explicitly passmax_retry_interval value greater than 0 to actually enable retries on errors.

Upgrade Notes¶

• The allowed values for theconnection_debug option are now restricted to the range between 0 and 100 (inclusive). Previously a number lower than 0 or higher than 100 could be given without error. But now, aConfigFileValueError will be raised when the option value is outside this range.

New Features¶

• enginefacade decorators can now be used for class and instance methods, which implicitly receive the first positional argument. Previously, it was required that all decorated functions receive a context value as the first argument.

Deprecation Notes¶

• The configuration optionsqlite_db is now deprecated andwill be removed in the future. Please use configurationoptionconnection orslave_connection to connect to the database.

Upgrade Notes¶

• The default value ofmax_overflow config optionhas been increased from 10 to 50 in order to allowOpenStack services heavily using DBs to better handlespikes of concurrent requests and lower the probabilityof getting a pool timeout issue.

  This change potentially leads to increasing of the numberof open connections to an RDBMS server. Depending on theconfiguration, you may see “too many connections” errorsin logs of OpenStack services / RDBMS server. The max limit ofconnections can be set by the means of these config options:

  http://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_max_connectionshttp://www.postgresql.org/docs/current/static/runtime-config-connection.html#GUC-MAX-CONNECTIONS

  For details, please see the following LP:

  https://bugs.launchpad.net/oslo.db/+bug/1535375

  and the ML thread:

  http://lists.openstack.org/pipermail/openstack-dev/2015-December/082717.html

Other Notes¶

• Introduce reno for deployer release notes.