The template in Compass for Faceted search uses outdated datatypes - stringFacet, numberFacet, dateFacet. 

{
  "mappings": {
    "dynamic": true,
    "fields": {
      <number field name for faceting>: [
        {
          "type": "numberFacet"
        },
        {
          "type": "number"
        },
      ],
      <date field name for faceting>: [
        {
            "type": "dateFacet"
        }
        {
            "type": "date"
        }
      ],
      <string field name for faceting>: [
        {
          "type": "stringFacet"
        },
        {
          "type": "string",
          "analyzer": "lucene.keyword"
        },
      ],
    } 
  }
} 

Instead, we could use recommended field mappings 

{
  "mappings": {
    "dynamic": true,
    "fields": {
      <number field name for faceting>: [
  
        {
          "type": "number"
        },
      ],
      <date field name for faceting>: [
     
        {
            "type": "date"
        }
      ],
      <string field name for faceting>: [
     
        {
          "type": "token"
        },
      ],
    } 
  }
} 

cc amy.jian@mongodb.com