Hello and welcome to the latest edition of the WMF Engineering Roadmap and Deployment update.

The full log of planned deployments next week can be found at: https://wikitech.wikimedia.org/wiki/Deployments#Week_of_September_15th

A quick list of notable items...

== Monday == * Revert Wikidata to a known-good version due to issues that were found on Thursday's deploy

* Update CentralNotice to remove dependency on jquery.json ** https://gerrit.wikimedia.org/r/158103

* Japanese Wikipedia to get Cirrus Search as the primary search experience

== Tuesday == * Commons to will get the new CirrusSearch as the primary search engine

* MediaWiki deploy ** group1 to 1.24wmf21: All non-Wikipedia sites (Wiktionary, Wikisource, Wikinews, Wikibooks, Wikiquote, Wikiversity, and a few other sites) ** https://www.mediawiki.org/wiki/MediaWiki_1.24/wmf21

== Wednesday == * Russian Wikipedia to get Cirrus Search as the primary search experience

== Thursday == * MediaWiki deploy ** group2 to 1.24wmf21 (all Wikipedias) ** group0 to 1.24wmf22 (test/test2/testwikidata/mediawiki)

* There will be a method to opt-in to using the new HHVM-powered backend for all WMF wikis. It'll be implemented via a BetaFeature to make it as easy as possible for people to participate. There should be no noticeable negative impact and hopefully only positive impacts.

Thanks and as always, questions and comments welcome,

Greg