opened
SPMaibornwolff
username_0
Elcep should log the failures which are returned by the Elasticsearch API. 
I.e. a request with a missing configuration for text field aggregation does not fail. Instead it returns a document with failures:
`{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 2,
        "successful": 3,
        "skipped": 4,
        "failed": 4,
        "failures": [
            {
                "shard": 0,
                "index": "index",
                "node": "node",
                "reason": {
                    "type": "illegal_argument_exception",
                    "reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [text_field_name] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."
                }
            }
        ]
    },
    ...
}`
Such failures should be logged.
Log failures returned by the Elasticsearch API
issue