Hi, we are planning to upgrade the ICU library on MediaWiki app servers from version 67 to version 72. This is a prerequisite to upgrading the OS and other software on those machines, and allows developers to use new internationalization features including support for Unicode 15.
There will be one user-visible effect: Category lists will be displayed out of order during the transition. This time around, we are trying a new process that minimizes this disruption (created in T263437) on smaller wikis, but as it has not been done before, we will not use it for the largest wikis yet. Therefore:
- New process: the expected disruption is under 30 minutes.
- Old process: the expected disruption will be up to several days, and about a week for enwiki.
Also note that if something goes very wrong with the new process, we will revert to the old process (and thus to the longer disruption).
List of affected wikis
New process:
- mediawikiwiki
- arwiktionary
- azwiki
- azwikibooks
- azwikiquote
- azwikisource
- azwiktionary
- be_x_oldwiki
- bewiki
- bewikisource
- bswiki
- bswiktionary
- bswikiquote
- cswiktionary
- cywiki
- cywikibooks
- cywikiquote
- cywikisource
- cywiktionary
- dewikisource
- eswikiversity
- etwiki
- etwikibooks
- etwikimedia
- etwikiquote
- etwikisource
- etwiktionary
- fawikisource
- fawiktionary
- fawikibooks
- fawikinews
- fawikiquote
- fiwikibooks
- fiwikimedia
- fiwikinews
- fiwikiquote
- fiwikisource
- fiwikiversity
- fiwikivoyage
- frwikibooks
- frwikinews
- frwikiversity
- gawiki
- gdwiki
- gewikimedia
- glwiki
- grwikimedia
- hrwiki
- hsbwiki
- idwikimedia
- id_internalwikimedia
- ilowiki
- iswiki
- kkwiki
- kuwiki
- kuwiktionary
- kuwikibooks
- kuwikiquote
- lbwiki
- ltwiki
- lvwiki
- mkwiki
- napwikisource
- nnwiki
- nowikimedia
- olowiki
- plwikiquote
- plwikisource
- plwikivoyage
- plwiktionary
- ptwikibooks
- romdwikimedia
- rowikibooks
- rowikinews
- rowikiquote
- rowikisource
- rowikivoyage
- rowiktionary
- rswikimedia
- ruwikibooks
- ruwikiquote
- ruwikisource
- ruwikiversity
- ruwikivoyage
- ruwiktionary
- sewiki
- simplewiki
- slwiki
- slwikibooks
- slwikiquote
- slwikisource
- slwikiversity
- slwiktionary
- sqwiki
- sqwikibooks
- sqwikinews
- sqwikiquote
- srwikibooks
- srwikinews
- srwikiquote
- srwikisource
- srwiktionary
- skwiki
- svwikisource
- tawiki
- tawikibooks
- tawikinews
- tawikiquote
- tawikisource
- tawiktionary
- testwiki
- thwikibooks
- thwikinews
- thwikiquote
- thwikisource
- thwiktionary
- trwikiquote
- trwiktionary
- uawikimedia
- ukwikibooks
- ukwikinews
- ukwikiquote
- ukwikisource
- ukwikivoyage
- ukwiktionary
- viwikibooks
- viwikiquote
- viwikisource
- viwikivoyage
- viwiktionary
Old process:
- enwiki
- cswiki
- fiwiki
- itwiki
- nlwiki
- nowiki
- plwiki
- ptwiki
- svwiki
- thwiki
- trwiki
- azwikimedia
- cswikivoyage
- shwiki
- srwiki
- trwikivoyage
- frwiki
- ruwiki
- eswiki
- fawiki
- frwiktionary
- huwiki
- rowiki
- ukwiki
- viwiki
- ruwikinews
The reason for the category ordering disruption: ICU functionality is involved in multi-lingual sorting keys, among other things, and those sorting keys will change with the new version. Categories sorted with the old ICU, but displayed with the new one, will be shown out of order until they're updated. This means that:
- For the new process: We will pre-compute the updated sorting keys, and after deploying the new ICU version, we will swap the new keys in place. Thus the disruption time is only the time needed for us to roll out the ICU library upgrade and then do the database table swap.
- For the old process: We will deploy the new ICU version, and then run a maintenance script to update each page. Last time, it took about a week to get all the way through enwiki.
We expect to start the upgrade around Apr 7 (exact date to be confirmed with DBAs, I will update you).
There does not appear to be a CommRel support task for the previous upgrade (T345561), but there is one for the one before that: T267145 .
For your reference: More technical details about this upgrade are in the parent task T419049 and its subtasks. The development of the new process was tracked in T263437.