placement/releasenotes/notes/placement-database-2e087f379273535d.yaml
Matt Riedemann bd4ba8d12b Clarify placement DB schema migration
This just clarifies in the release note for the optional
placement database that the database itself is not created
when running "nova-manage api_db sync", but rather the
database schema is created. This is important since a
non-trivial number of people over the years have thought
that the db sync commands actually create a database, which
they do not.

Change-Id: Ie6c3a5dc61a288935829276cc72f7f7563e20420
2018-06-18 16:56:24 -04:00

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YAML

---
features:
- |
An optional configuration group ``placement_database`` can be used in
nova.conf to configure a separate database for use with the placement
API.
If ``placement_database.connection`` has a value then the
``placement_database`` configuration group will be used to configure a
separate placement database, including using ``connection`` to identify the
target database. That database will have a schema that is a replica of all
the tables used in the API database. The new database schema will be
created and synchronized when the ``nova-manage api_db sync`` command is
run.
When the ``placement_database.connection`` setting is omitted the existing
settings for the ``api_database`` will be used for hosting placement data.
Setting ``placement_database.connection`` and calling
``nova-manage api_db sync`` will only create tables. No data will be
migrated. In an existing OpenStack deployment, if there is existing
placement data in the ``nova_api`` database this will not be copied. It is
up to the deployment to manually replicate that data in a fashion that
works best for the environment.