openstack/glance
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Alembic migrations/rolling upgrades release note

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This releasenote describes the effect of the following changes:
  * Ie8594ff339a13bf190aefa308f54e97ee20ecfa2
  * I77921366a05ba6f9841143af89c1f4059d8454c6
  * Ie839e0f240436dce7b151de5b464373516ff5a64
  * I34f5623d6804e9fe594e6b5b196ea4a162578196

Change-Id: Iaa411c3f3bbe5397da239409f504dcb4d769b08b
This commit is contained in:
Brian Rosmaita 2017-02-01 18:29:01 -05:00
parent 3f98eb08fa
commit fb851b9ead
1 changed files with 38 additions and 0 deletions
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releasenotes/notes/alembic-migrations-902b31edae7a5d7d.yaml Normal file
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---
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