How to fix ElasticSearch ‘Root mapping definition has unsupported parameters’

Problem:

You want to create an ElasticSearch index with a custom mapping or update the mapping of an existing ElasticSearch index but you see an error message like

elasticsearch.exceptions.RequestError: RequestError(400, 'mapper_parsing_exception', 'Root mapping definition has unsupported parameters:  [mappings : {properties={num_total={type=integer}, approved={type=integer}, num_translated={type=integer}, pattern_length={type=integer}, num_unapproved={type=integer}, pattern={type=keyword}, num_approved={type=integer}, translated={type=integer}, untranslated={type=integer}, num_untranslated={type=integer}, group={type=keyword}}}]')

Solution:

This can point to multiple issues. Essentially, ElasticSearch is trying to tell you that the structure of your JSON is not correct.

Often this error is misinterpreted as individual field definitions being wrong, but this is rarely the issue (and only if an individual field definition is completely malformed).

If your message is structured like

... unsupported parameters:  [mappings : ...

then the most likely root cause is that you have mappings nested inside mappings in your JSON. This also applies if you update a mapping (put_mapping) – in this case the outer mapping is implicit!

Example: Your code looks like this:

es.indices.put_mapping(index='my_index, doc_type='_doc', body={
    "mappings": {
        "properties": {
            "pattern": {
                "type":  "keyword"
            }
        }
    }
})

ElasticSearch will internally create a JSON like this internally:

{
    "mappings": {
        "mappings": {
            "properties": {
                "pattern": {
                    "type":  "keyword"
                }
            }
        }
    }
}

See that there are two mappings inside each other? ElasticSearch does not view this as a correctly structured JSON, therefore you need to remove the "mapping": {...} from your code, resulting in

es.indices.put_mapping(index='my_index, doc_type='_doc', body={
    "properties": {
        "pattern": {
            "type":  "keyword"
        }
    }
})