Manual:Upgrading to 1.9



The MediaWiki team kicks off 2007 with the release of 1.9, and as ever, a whole host of new features and fixes. This guide will help users of older versions upgrade in a smooth fashion. The information here should be valid for MediaWiki 1.5 upwards.

Overview
First, read the UPGRADE text file included in MediaWiki 1.9.

As with all MediaWiki upgrades, the basic premise is the same:
 * 1) Check the requirements
 * 2) Read the release notes
 * 3) Back up existing files and the database
 * 4) Unpack the new files
 * 5) Run the update script to check the database
 * 6) Upgrade extensions
 * 7) Test the update

Check requirements
MediaWiki 1.9 requires:


 * PHP 5.0 or later (5.1 recommended)
 * PHP 4 has not been supported since 1.7
 * Note: PHP 5.0 has bugs on 64-bit systems which cause fundamental problems with MediaWiki. If you are running on an x86_64 (AMD64, EMT64) or other affected 64-bit platform, you must run PHP 5.1 or higher.


 * MySQL 4.0 or later
 * MySQL 3.x has not been supported since 1.6

Read the release notes
Within the distribution tarball, or within the files checked out/exported from SVN, there are a number of files with capitalised filenames, one of which contains the RELEASE-NOTES. Now's the time to open it up and find out what's been changed in 1.9.

Back up existing files and the database
While the upgrade scripts are well-maintained and robust, things could still go pear-shaped. Before proceeding to update the database schema, make a full backup of the wiki, including both the database and the files.

Database
Make a full backup of the wiki database before attempting to run update scripts on it. This serves as a basic precaution should the schema updates fail, leaving records in a broken or corrupt state. There are a number of utilities to do this, such as MySQL dump, which is supplied with the MySQL software.

Settings
Make a copy of your LocalSettings.php file, which contains both the basic configuration details, and also any customisations you may have made to change the behaviour of MediaWiki.

Uploaded files
If uploads are enabled in the wiki, then you will also need to back up the upload directory. By default, this is the images directory, although the path to this may have been changed in LocalSettings.php.

Extensions and custom skins
Make copies of the extensions directory, and any files or directories containing skin customisations.

Unpack the new files
If using a tarball package downloaded from SourceForge, decompress it; if using Subversion, export the files into a clean location. Replace all existing files with the new versions from 1.9, preserving the directory structure. The core code is now up to date.

Run the update script
Note: Make sure there's an AdminSettings.php file in the wiki root, and it's got up to date information in it. The user needs full permissions on the database.

The preferred method of performing the update is using the command-line maintenance script, however, it is also possible to re-run the web-based installer.

Shell
From the command line, or an SSH shell or similar, change to the maintenance directory and execute the update script:

$ php update.php

MediaWiki will inspect the existing schema and update it to work with the new code, adding tables and columns as needed. If upgrading from 1.5.x, once this is complete, you are advised to run the refreshLinks.php script to update the link tables.

Alternative 1: phpShell
If shell access is not available, look at options such as phpShell, which emulates a command prompt using PHP functions. This might not work on some locked-down hosting setups.

When using such a solution, it is often desirable to skip the countdown period at the start of the script. Pass the --quick</tt> option to the update script to do so:

$ php update.php --quick

Alternative 2: Re-run the installer
An alternative to running the update script from the shell is to re-run the web installer. To do this:


 * 1) Rename LocalSettings.php</tt> to LocalSettings.old.php</tt>
 * 2) Make the config</tt> directory writable by the web server
 * 3) Browse to the wiki and start the installer

Fill in the form fields with the same values as was done during the previous version's installation. When the installation process starts, the script will detect existing MediaWiki tables, and upgrade their schema. When this is complete, a new LocalSettings.php</tt> will be generated.


 * 1) Delete the new configuration file
 * 2) Rename LocalSettings.old.php</tt> back to LocalSettings.php</tt>
 * 3) Restore permissions on the config</tt> directory

Upgrade extensions
Certain extensions have been updated in order to work with MediaWiki 1.9. Be sure to upgrade to the latest versions of such extensions. You might need to perform manual updates to custom extensions.

Test the update
Once the upgrade has completed, browse to the wiki and check basics such as viewing and editing pages to ensure things still work as expected.

Visit Special:Version and check that the version shown is correct.