In https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/381257, removed usage of FuzzyLikeThis in favor of simple fuzzy match but this caused T177727: Translation memory not working for anything longer and hence the change was reverted.
In https://phabricator.wikimedia.org/T177727#3668337, https://github.com/codelibs/elasticsearch-minhash was suggested as a replacement.
Documentation on top of FuzzyLikeThis class:
/** * NOTE: the following class has been copied from elastica 2.3.1 : * https://github.com/ruflin/Elastica/blob/2.3.1/lib/Elastica/Query/FuzzyLikeThis.php * (few modifications have been made to comply with phpcs rules used by this extension) * It is intended to be used as a temporary workaround with the wmf extra * elasticsearch plugin with elasticsearch 2.x. */