Defunct functions in elasticSource:
mlt(): The MLT API has been removed, use More Like This Query via
nodes_shutdown(): The _shutdown API has been removed. Instead, setup Elasticsearch to run as a service (see Running as a Service on Linux (https://www.elastic.co/guide/en/elasticsearch/reference/2.0/setup-service.html) or Running as a Service on Windows (https://www.elastic.co/guide/en/elasticsearch/reference/2.0/setup-service-win.html)) or use the -p command line option to write the PID to a file.
index_status(): _status route for the index API has been removed. Replaced with the Indices Stats and Indices Recovery APIs.
mapping_delete(): Elasticsearch dropped this route in their API. Instead of deleting a mapping, delete the index and recreate with a new mapping.