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MySQL backend fixes for Python 3.
With Python 2, text sent to and from MySQL is treated as bytes in
Python. The database may be recorded by MySQL as having some other
encoding (latin1 being the default in some MySQL versions - Roundup
does not set an encoding explicitly, unlike in back_postgresql), but
as long as MySQL's notion of the connection encoding agrees with its
notion of the database encoding, no conversions actually take place
and the bytes are stored and returned as-is.
With Python 3, text sent to and from MySQL is treated as Python
Unicode strings. When the database and connection encoding is latin1,
that means the bytes stored in the database under Python 2 are
interpreted as latin1 and converted from that to Unicode, producing
incorrect results for any non-ASCII characters; furthermore, if trying
to store new non-ASCII data in the database under Python 3, any
non-latin1 characters produce errors.
This patch arranges for both the connection and database character
sets to be UTF-8 when using Python 3, and documents a need to export
and import the database when moving from Python 2 to Python 3 with
this backend.
| author | Joseph Myers <jsm@polyomino.org.uk> |
|---|---|
| date | Sun, 16 Sep 2018 16:19:20 +0000 |
| parents | e2978ed3b550 |
| children | 0df5f9eeefd4 |
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============= MySQL Backend ============= This notes detail the MySQL backend for the Roundup issue tracker. Prerequisites ============= To use MySQL as the backend for storing roundup data, you also need to install: 1. MySQL RDBMS 4.0.18 or higher - http://www.mysql.com. Your MySQL installation MUST support InnoDB tables (or Berkeley DB (BDB) tables if you have no other choice). If you're running < 4.0.18 (but not <4.0) then you'll need to use BDB to pass all unit tests. Edit the ``roundup/backends/back_mysql.py`` file to enable DBD instead of InnoDB. 2. Python MySQL interface - https://pypi.org/project/mysqlclient/ Other Configuration =================== If you are indexing large documents (e.g attached file contents) using MySQL, you may need to increase the max_allowed_packet size. If you don't you can see the error:: 'MySql Server has gone away (2006)' To do this edit /etc/my.conf and change:: [mysqld] max_allowed_packet = 1M the 'max_allowed_packet' value from '1M' to '64M' or larger. Alternatively you can install an alternate indexer (whoosh, xapian etc.) and force the tracker to use it by setting the ``indexer`` setting in the tracker's ``config.ini``. This fix was supplied by telsch. See issue http://issues.roundup-tracker.org/issue2550743 for further info or if you are interested in developing a patch to roundup to help work around this issue. Running the MySQL tests ======================= Roundup tests expect an empty MySQL database. Two alternate ways to provide this: 1. If you have root permissions on the MySQL server, you can create the necessary database entries using the follwing SQL sequence. Use ``mysql`` on the command line to enter:: CREATE DATABASE rounduptest; USE rounduptest; GRANT ALL PRIVILEGES ON rounduptest.* TO rounduptest@localhost IDENTIFIED BY 'rounduptest'; FLUSH PRIVILEGES; 2. If your administrator has provided you with database connection info, see the config values in 'test/db_test_base.py' about which database connection, name and user will be used. The MySQL database should not contain any tables. Tests will not drop the database with existing data. Showing MySQL who's boss ======================== If things ever get to the point where that test database is totally hosed, just:: $ su - # /etc/init.d/mysql stop # rm -rf /var/lib/mysql/rounduptest # /etc/init.d/mysql start and all will be better (note that on some systems, ``mysql`` is spelt ``mysqld``).