openstack/ironic
Code Issues Proposed changes

Document caveats of running with SQLite

Browse Source 
Change-Id: I5d182814b07a2d50345ee365c56a0f00724f6e47
This commit is contained in:
Dmitry Tantsur 2023-07-14 11:24:22 +02:00
parent 54da324900
commit 267e61bbc7
1 changed files with 44 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
doc/source/install/include/common-prerequisites.inc
View File

@ -16,17 +16,17 @@ Set up the database for Bare Metal
The Bare Metal service stores information in a database. This guide uses the The Bare Metal service stores information in a database. This guide uses the
MySQL database that is used by other OpenStack services. MySQL database that is used by other OpenStack services.
#. In MySQL, create an ``ironic`` database that is accessible by the In MySQL, create an ``ironic`` database that is accessible by the
``ironic`` user. Replace ``IRONIC_DBPASSWORD`` with a suitable password: ``ironic`` user. Replace ``IRONIC_DBPASSWORD`` with a suitable password:
.. code-block:: console .. code-block:: console
# mysql -u root -p # mysql -u root -p
mysql> CREATE DATABASE ironic CHARACTER SET utf8mb3; mysql> CREATE DATABASE ironic CHARACTER SET utf8mb3;
mysql> GRANT ALL PRIVILEGES ON ironic.* TO 'ironic'@'localhost' \ mysql> GRANT ALL PRIVILEGES ON ironic.* TO 'ironic'@'localhost' \
IDENTIFIED BY 'IRONIC_DBPASSWORD'; IDENTIFIED BY 'IRONIC_DBPASSWORD';
mysql> GRANT ALL PRIVILEGES ON ironic.* TO 'ironic'@'%' \ mysql> GRANT ALL PRIVILEGES ON ironic.* TO 'ironic'@'%' \
IDENTIFIED BY 'IRONIC_DBPASSWORD'; IDENTIFIED BY 'IRONIC_DBPASSWORD';
.. note:: .. note::
When creating the database to house Ironic, specifically on MySQL/MariaDB, When creating the database to house Ironic, specifically on MySQL/MariaDB,
@ -35,3 +35,38 @@ MySQL database that is used by other OpenStack services.
has traditionally meant ``utf8mb3``, short for "UTF-8, 3 byte encoding", has traditionally meant ``utf8mb3``, short for "UTF-8, 3 byte encoding",
however the platforms are expected to move to ``utf8mb4`` which is however the platforms are expected to move to ``utf8mb4`` which is
incompatible with Ironic. incompatible with Ironic.
Running on SQLite
^^^^^^^^^^^^^^^^^
It is possible to run the Bare Metal service with SQLite_ as the database
backend. However, take into account the following limitations:
* You have to run Ironic in the all-in-one mode (see `configuring
single-process ironic`_). You cannot have multiple conductors this way.
* You should use `WAL mode`_ for the database. Ironic will try to enable
it for you, but it can only be done for a fresh database.
* Even in the WAL mode, SQLite has limited write concurrency. If you
experience "database is locked" errors, try reducing the frequency
of periodic tasks. If that still does not help, you may need to use
a server-based database.
* Not all database migrations are supported on SQLite. You may need
to re-create the database on upgrades.
To use SQLite, configure your connection like this:
.. code-block:: ini
[database]
connection = sqlite:////full/path/to/ironic.sqlite
.. note::
This is not a typo! A full path requires 4 slashes.
If in doubt, use MySQL/MariaDB instead.
.. _sqlite: https://www.sqlite.org
.. _WAL mode: https://www.sqlite.org/wal.html