With reference to T133120 :
I have a series of Mediawiki systems and have recently upgraded to the 1.27 series for the long term support.
Given the LTS status of 1.27 I would like to stay on this series until the next LTS, but Elasticsearch 2.* integration is a very attractive function.
Is there a chance this effort to upgrade ES on wmf and 1.28 can be backported to 1.27?