Bonjour

Starting on November 16, 2020 the Wikimedia Foundation Operations team will migrate the servers running the MediaWiki application servers to a new release of the ICU https://en.wikipedia.org/wiki/International_Components_for_Unicode Unicode library (from version 57 to 63).

This unblocks some future work on upgrading the servers to a new Operating System release and will also allow the use of improved internationalisation in the future (as wikis will then be able to use features introduced by the new ICU release such as new collation definitions, and allows us to use a more recent version of Unicode in MediaWiki).

This migration will cause some unavoidable temporary user-visible impact: *The sorting of some category pages will be distorted* – all pages which have been updated with the new software version will use the new sorting while untouched pages still use the old sorting. As such, Ops need to run a maintenance script to update the sorting for old entries.

*The distortions may last from a few hours* (on medium-sized wikis), up to *a day* (on the largest wikis), and *a few days* on English Wikipedia. The start-time will depend upon when the migration script reaches each wiki.

The detailed list and the task for the technical implementation is at *T264991* https://phabricator.wikimedia.org/T264991.

This operation is announced in the next issues of Tech News https://meta.wikimedia.org/wiki/Tech/News. Please share this message where it needs to be posted!

Thank you,

Benoît