Wiki Migration

In advance

• Add wiki role to target machine
• Do initial rsync of /srv/wiki.openstreetmap.org [can repeat as needed]
• Stop chef on target machine
• Remove /etc/cron.d/mediawiki-wiki_openstreetmap_org on target machine
• Remove /etc/cron.daily/mediawiki-wiki_openstreetmap_org-backup on target machine

On the day

• Stop apache on target machine
• Stop chef on source machine
• Set $wgReadOnly in LocalSettings.php on source machine
• Remove /etc/cron.d/mediawiki-wiki_openstreetmap_org on source machine
• Remove /etc/cron.daily/mediawiki-wiki_openstreetmap_org-backup on source machine
• Make mysql read only on source machine
  • FLUSH TABLES WITH READ LOCK;
  • SET GLOBAL read_only = 1;
• Do final rsync of /srv/wiki.openstreetmap.org [can repeat as needed]
• Dump database on source machine
  • mysqldump --opt --skip-lock-tables --single-transaction --user=wiki-user --password "wiki" | lz4 -9 > wiki.sql.lz4
• Copy database dump to target machine
• Restore database dump on target machine
  • lz4cat wiki.sql.lz4 | mysql --user=wiki-user --password wiki
• Run chef on target machines
• Switch DNS over
• Make mysql read/write on source machine
  • SET GLOBAL read_only = 0;
  • UNLOCK TABLES;
• Remove wiki role from source machine
• Run chef on source machine
• Rebuild indexes on target machine
  • sudo -u www-data php /srv/wiki.openstreetmap.org/w/extensions/CirrusSearch/maintenance/updateSearchIndexConfig.php --reindexAndRemoveOk --indexIdentifier now
  • sudo -u www-data php /srv/wiki.openstreetmap.org/w/extensions/CirrusSearch/maintenance/forceSearchIndex.php --skipLinks --indexOnSkip
  • sudo -u www-data php /srv/wiki.openstreetmap.org/w/extensions/CirrusSearch/maintenance/forceSearchIndex.php --skipParse