The delete by query plugin adds support for deleting all of the documents (from one or more indices) which match the specified query. It is a replacement for the problematic delete-by-query functionality which has been removed from Elasticsearch core in 2.0. Internally, it uses the Scan/Scroll and Bulk APIs to delete documents in an efficient and safe manner. It is slower than the old delete-by-query functionality, but fixes the problems with the previous implementation.
Closes#7052