Remove date histogram boolean support (elastic#118484)

This removes support for running date aggregations over boolean fields. This has never been useful, was deprecated in 7.x, and is finally being disabled for 9.0.

build-tools-internal/src/main/resources/changelog-schema.json

@@ -279,6 +279,7 @@
     "compatibilityChangeArea": {
       "type": "string",
       "enum": [
+        "Aggregations",
         "Analysis",
         "Authorization",
         "Cluster and node setting",

docs/changelog/118484.yaml

@@ -0,0 +1,14 @@
+pr: 118484
+summary: Remove date histogram boolean support
+area: Aggregations
+type: breaking
+issues: []
+breaking:
+  title: Remove date histogram boolean support
+  area: Aggregations
+  details: Elasticsearch no longer allows running Date Histogram aggregations
+           over boolean fields. Instead, use Terms aggregation for boolean
+           fields.
+  impact: We expect the impact to be minimal, as this never produced good
+          results, and has been deprecated for years.
+  notable: false

server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramAggregatorFactory.java

@@ -11,7 +11,6 @@
 
 import org.elasticsearch.ElasticsearchStatusException;
 import org.elasticsearch.common.Rounding;
-import org.elasticsearch.common.logging.DeprecationCategory;
 import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.rest.RestStatus;
 import org.elasticsearch.search.aggregations.Aggregator;
@@ -42,49 +41,6 @@ public static void registerAggregators(ValuesSourceRegistry.Builder builder) {
         );
 
         builder.register(DateHistogramAggregationBuilder.REGISTRY_KEY, CoreValuesSourceType.RANGE, DateRangeHistogramAggregator::new, true);
-
-        builder.register(
-            DateHistogramAggregationBuilder.REGISTRY_KEY,
-            CoreValuesSourceType.BOOLEAN,
-            (
-                name,
-                factories,
-                rounding,
-                order,
-                keyed,
-                minDocCount,
-                downsampledResultsOffset,
-                extendedBounds,
-                hardBounds,
-                valuesSourceConfig,
-                context,
-                parent,
-                cardinality,
-                metadata) -> {
-                DEPRECATION_LOGGER.warn(
-                    DeprecationCategory.AGGREGATIONS,
-                    "date-histogram-boolean",
-                    "Running DateHistogram aggregations on [boolean] fields is deprecated"
-                );
-                return DateHistogramAggregator.build(
-                    name,
-                    factories,
-                    rounding,
-                    order,
-                    keyed,
-                    minDocCount,
-                    downsampledResultsOffset,
-                    extendedBounds,
-                    hardBounds,
-                    valuesSourceConfig,
-                    context,
-                    parent,
-                    cardinality,
-                    metadata
-                );
-            },
-            true
-        );
     }
 
     private final DateHistogramAggregationSupplier aggregatorSupplier;

server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTests.java

@@ -83,9 +83,9 @@ public class DateHistogramAggregatorTests extends DateHistogramAggregatorTestCas
         "2017-12-12T22:55:46"
     );
 
-    public void testBooleanFieldDeprecated() throws IOException {
+    public void testBooleanFieldUnsupported() throws IOException {
         final String fieldName = "bogusBoolean";
-        testCase(iw -> {
+        IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> testCase(iw -> {
             Document d = new Document();
             d.add(new SortedNumericDocValuesField(fieldName, 0));
             iw.addDocument(d);
@@ -95,8 +95,8 @@ public void testBooleanFieldDeprecated() throws IOException {
                 new DateHistogramAggregationBuilder("name").calendarInterval(DateHistogramInterval.HOUR).field(fieldName),
                 new BooleanFieldMapper.BooleanFieldType(fieldName)
             )
-        );
-        assertWarnings("Running DateHistogram aggregations on [boolean] fields is deprecated");
+        ));
+        assertThat(e.getMessage(), equalTo("Field [bogusBoolean] of type [boolean] is not supported for aggregation [date_histogram]"));
     }
 
     public void testMatchNoDocs() throws IOException {