39 lines
1.9 KiB
YAML
39 lines
1.9 KiB
YAML
---
|
|
prelude: >
|
|
- **Experimental** zero-downtime database upgrade using an
|
|
expand-migrate-contract series of operations is available.
|
|
upgrade:
|
|
- |
|
|
The database migration engine used by Glance for database upgrades has been
|
|
changed from *SQLAlchemy Migrate* to *Alembic* in this release.
|
|
|
|
* This has necessitated a change in the location and naming convention for
|
|
migration scripts. Developers, operators, and DevOps are strongly
|
|
encouraged to read through the `Database Management`_ section of the
|
|
Glance documentation for details of the changes introduced in the Ocata
|
|
release. Here's a brief summary of the changes:
|
|
|
|
- All the ``glance manage db`` commands are changed appropriately to use
|
|
Alembic to perform operations such as ``version``, ``upgrade``,
|
|
``sync`` and ``version_control``. Hence, the "old-style" migration
|
|
scripts will no longer work with the Ocata glance manage db commands.
|
|
|
|
- Database versions are no longer numerical. Instead, they are the
|
|
*revision ID* of the last migration applied on the database.
|
|
|
|
* For example, the Liberty migration, which was version ``42`` under
|
|
the old system, will now appear as ``liberty``. The Mitaka
|
|
migrations ``43`` and ``44`` appear as ``mitaka01`` and ``mitaka02``,
|
|
respectively.
|
|
|
|
* The change in migration engine has been undertaken in order to enable
|
|
zero-downtime database upgrades, which are part of the effort to
|
|
implement rolling upgrades for Glance (scheduled for the Pike release).
|
|
|
|
- A preview of zero-downtime database upgrades is available in this
|
|
release, but it is **experimental** and **not supported for production
|
|
systems**. Please consult the `Database Management`_ section of the
|
|
Glance documentation for details.
|
|
|
|
.. _`Database Management`: http://docs.openstack.org/developer/glance/db.html
|