After several months of hard work by the Discovery Search
<https://www.mediawiki.org/wiki/Wikimedia_Discovery/Search> team, we're
happy to announce that the CirrusSearch
<https://www.mediawiki.org/wiki/Extension:CirrusSearch> backend has been
upgraded to ElasticSearch
5. This update was bit tedious and difficult for the team; you can browse
the various tickets <https://phabricator.wikimedia.org/T154501> in
Phabricator if you'd like to know more.
This upgrade to ES5 is great, because we now have a new Ukrainian analyzer
to experiment with, a new reindexing API and soon, we’ll have an updated
completion suggester - all of which makes our backend more standard and
reduced a significant amount of technical debt.
Cheers from the Discovery Search Team!
Product Manager, Discovery