Vector tiles buffer is used to include data that is just outside of the tile. This data is used to prevent border effects when rendering the geometries. It is currently [hardcoded to 5 pixels](https://github.com/elastic/elasticsearch/blob/de2781f98696c1e6cfad2b5bf46fe752a5e3edbb/x-pack/plugin/vector-tile/src/main/java/org/elasticsearch/xpack/vectortile/feature/FeatureFactory.java#L63) but it should probably need to be user configurable by adding a new property on the vector tiles API which can change the value.




x-pack/plugin/vector-tile/src/main/java/org/elasticsearch/xpack/vectortile/rest/RestVectorTileAction.java
: null;
                    final Aggregations aggsWithoutGridAndBounds = searchResponse.getAggregations() == null
                        ? null
                        : new Aggregations(
                            searchResponse.getAggregations()
                                .asList()
                                .stream()
                                .filter(a -> GRID_FIELD.equals(a.getName()) == false && BOUNDS_FIELD.equals(a.getName()) == false)
                                .collect(Collectors.toList())
                        );
                    final SearchResponse meta = new SearchResponse(
                        new SearchResponseSections(
                            new SearchHits(
                                SearchHits.EMPTY,
                                searchResponse.getHits().getTotalHits(),
                                searchResponse.getHits().getMaxScore()
                            ), 
                            aggsWithoutGridAndBounds,
                            searchResponse.getSuggest(),
                            searchResponse.isTimedOut(),
                            searchResponse.isTerminatedEarly(),
                            searchResponse.getProfileResults() == null
                                ? null
                                : new SearchProfileResults(searchResponse.getProfileResults()),
                            searchResponse.getNumReducePhases()
                        ),
                        searchResponse.getScrollId(),
                        searchResponse.getTotalShards(),
                        searchResponse.getSuccessfulShards(),
                        searchResponse.getSkippedShards(),