Control storing array source with index setting

docs/changelog/112397.yaml

@@ -0,0 +1,5 @@
+pr: 112397
+summary: Control storing array source with index setting
+area: Mapping
+type: enhancement
+issues: []

modules/data-streams/src/javaRestTest/java/org/elasticsearch/datastreams/logsdb/qa/StandardVersusLogsIndexModeRandomDataChallengeRestIT.java

@@ -8,9 +8,11 @@
 
 package org.elasticsearch.datastreams.logsdb.qa;
 
+import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.time.DateFormatter;
 import org.elasticsearch.common.time.FormatNames;
 import org.elasticsearch.core.CheckedConsumer;
+import org.elasticsearch.index.mapper.Mapper;
 import org.elasticsearch.index.mapper.ObjectMapper;
 import org.elasticsearch.logsdb.datageneration.DataGenerator;
 import org.elasticsearch.logsdb.datageneration.DataGeneratorSpecification;
@@ -36,12 +38,14 @@
  */
 public class StandardVersusLogsIndexModeRandomDataChallengeRestIT extends StandardVersusLogsIndexModeChallengeRestIT {
     private final ObjectMapper.Subobjects subobjects;
+    private final boolean keepArraySource;
 
     private final DataGenerator dataGenerator;
 
     public StandardVersusLogsIndexModeRandomDataChallengeRestIT() {
         super();
         this.subobjects = randomFrom(ObjectMapper.Subobjects.values());
+        this.keepArraySource = randomBoolean();
 
         var specificationBuilder = DataGeneratorSpecification.builder().withFullyDynamicMapping(randomBoolean());
         if (subobjects != ObjectMapper.Subobjects.ENABLED) {
@@ -120,6 +124,13 @@ public void contenderMappings(XContentBuilder builder) throws IOException {
         }
     }
 
+    @Override
+    public void contenderSettings(Settings.Builder builder) {
+        if (keepArraySource) {
+            builder.put(Mapper.SYNTHETIC_SOURCE_KEEP_INDEX_SETTING.getKey(), "arrays");
+        }
+    }
+
     @Override
     protected XContentBuilder generateDocument(final Instant timestamp) throws IOException {
         var document = XContentFactory.jsonBuilder();