Vector tile development is completed and this feature is ready to be released on 7.15. It is initially release as an experimental feature.
In particular this new feature introduces a new endpoint for generating vector tiles from geospatial data stored in Elasticsearch. This is a functionality that is interesting for any application that wants to render geospatial information stored in Elasticsearch on a map. The basic way to call this new end point looks like:
```
GET {index}/_mvt/{geo_field}/{z}/{x}/{y}
```
The return of this call is a vector tile as defined in the [MapBox vector tile specification](https://github.com/mapbox/vector-tile-spec/tree/master/2.1) so it can be easily render by any map supporting this format.
GeoFormatterFactory doesn't need to know that the extension points were created
specifically for the purpose of generating vector tiles. We can make it support
an arbitrary formats by moving all MVT-specific logic into formatter itself.
Follow up for #75367
In this commit we extend the Fields API formats for geo data in order to produce vector tiles features directly
on the data nodes. That helps the vector tile API to reduce the size of the data that needs to pull in order to
create the answer.
Following the same structure of the _search API, this changes makes possible to define some
body parameters as query parameters (e.g. defined as URL parameters)
In addition, a few things have been added:
* The API now handles cancellation which it turned to be a big performance booster.
* The API supports defining a sort field.
* RestVectorTileAction has been refactor to one class again.
* VectorTileRequest class has been extracted so it can be unit tested.
Ignacio Vera
Igor Motov
Rory Hunter