In 2.x, all fields must adhere to the same data type or you will get a failure [1]. To quote: Fields with the same name, in the same index, in different typ

In 2.x, all fields must adhere to the same data type or you will get a failure [1]. To quote: Fields with the same name, in the same index, in different types, must have the same mapping So hopefully this isn't an issue anymore! I do strongly suggest (and we've done this from the beginning) that no one rely on elasticsearch's auto mapping and that you should explicitly map your fields. [1] -- https://www.elastic.co/guide/en/elasticsearch/reference/current/breaking_20_mapping_changes.html https://www.elastic.co/guide/en/elasticsearch/reference/curr...