Elasticsearch, Kibana and duplicate keys in JSON

JSON has been the lingua franca of data exchange for many years. It's human-readable, lightweight and widely supported. However, the JSON spec does not define what parsers should do when they encounter a duplicate key in an object, e.g.:

  "foo": "spam",
  "foo": "eggs",
Implementations are free to interpret this how they like. When different systems have different interpretations this can cause problems. We recently encounter...Continue reading