{
    "settings": {
        "index": {
            "number_of_shards": 3,
            "number_of_replicas": 1,
            "sort.field": "topic",
            "sort.order": "asc"
        }
    },
    "mappings": {
        "properties": {
            "topic": {
                "type": "keyword"
            }
        }
    }
}