[7.x] [RollupV2] Move rollup metadata to field mappings (#70647)

Backports #69921 to 7.x

    This PR moves field related rollup metadata from the index metadata to the field mapping metadata.

    date_histogram fields is moved to the timestamp field (fields are fixed_interval or calendar_interval, time_zone)
    histogram fields are moved to the numeric field on which the the histogram is computed (the field is named interval)

    Also, the index uuid has been added to the index rollup settings as index.rollup.source.uuid and index.rollup.source.name

    The rest of the RollupMetadata has been removed. Finally, no rollup metadata exists in the global cluster state

Co-authored-by: Tal Levy <[email protected]>

Author: csoulios

server/src/main/java/org/elasticsearch/cluster/ClusterModule.java

@@ -23,7 +23,6 @@
 import org.elasticsearch.cluster.metadata.MetadataMappingService;
 import org.elasticsearch.cluster.metadata.MetadataUpdateSettingsService;
 import org.elasticsearch.cluster.metadata.RepositoriesMetadata;
-import org.elasticsearch.cluster.metadata.RollupMetadata;
 import org.elasticsearch.cluster.routing.DelayedAllocationService;
 import org.elasticsearch.cluster.routing.allocation.AllocationService;
 import org.elasticsearch.cluster.routing.allocation.ExistingShardsAllocator;
@@ -66,7 +65,6 @@
 import org.elasticsearch.persistent.PersistentTasksCustomMetadata;
 import org.elasticsearch.persistent.PersistentTasksNodeService;
 import org.elasticsearch.plugins.ClusterPlugin;
-import org.elasticsearch.rollup.RollupV2;
 import org.elasticsearch.script.ScriptMetadata;
 import org.elasticsearch.snapshots.SnapshotsInfoService;
 import org.elasticsearch.tasks.Task;
@@ -138,9 +136,6 @@ public static List<Entry> getNamedWriteables() {
             ComposableIndexTemplateMetadata::readDiffFrom);
         registerMetadataCustom(entries, DataStreamMetadata.TYPE, DataStreamMetadata::new, DataStreamMetadata::readDiffFrom);
 
-        if (RollupV2.isEnabled()) {
-            registerMetadataCustom(entries, RollupMetadata.TYPE, RollupMetadata::new, RollupMetadata::readDiffFrom);
-        }
         // Task Status (not Diffable)
         entries.add(new Entry(Task.Status.class, PersistentTasksNodeService.Status.NAME, PersistentTasksNodeService.Status::new));
         return entries;
@@ -194,10 +189,6 @@ public static List<NamedXContentRegistry.Entry> getNamedXWriteables() {
             ComposableIndexTemplateMetadata::fromXContent));
         entries.add(new NamedXContentRegistry.Entry(Metadata.Custom.class, new ParseField(DataStreamMetadata.TYPE),
             DataStreamMetadata::fromXContent));
-        if (RollupV2.isEnabled()) {
-            entries.add(new NamedXContentRegistry.Entry(Metadata.Custom.class, new ParseField(RollupMetadata.TYPE),
-                RollupMetadata::fromXContent));
-        }
         return entries;
     }
 

server/src/main/java/org/elasticsearch/cluster/metadata/IndexMetadata.java

@@ -146,6 +146,7 @@ static Setting<Integer> buildNumberOfShardsSetting() {
     public static final Setting<Integer> INDEX_ROUTING_PARTITION_SIZE_SETTING =
             Setting.intSetting(SETTING_ROUTING_PARTITION_SIZE, 1, 1, Property.IndexScope);
 
+    @SuppressWarnings("Convert2Diamond") // since some IntelliJs mysteriously report an error if an <Integer> is replaced with <> here:
     public static final Setting<Integer> INDEX_NUMBER_OF_ROUTING_SHARDS_SETTING = Setting.intSetting(
         "index.number_of_routing_shards",
         INDEX_NUMBER_OF_SHARDS_SETTING,
@@ -591,6 +592,13 @@ public Index getResizeSourceIndex() {
             INDEX_RESIZE_SOURCE_UUID.get(settings)) : null;
     }
 
+    public static final String INDEX_ROLLUP_SOURCE_UUID_KEY = "index.rollup.source.uuid";
+    public static final String INDEX_ROLLUP_SOURCE_NAME_KEY = "index.rollup.source.name";
+    public static final Setting<String> INDEX_ROLLUP_SOURCE_UUID = Setting.simpleString(INDEX_ROLLUP_SOURCE_UUID_KEY,
+        Property.IndexScope, Property.PrivateIndex);
+    public static final Setting<String> INDEX_ROLLUP_SOURCE_NAME = Setting.simpleString(INDEX_ROLLUP_SOURCE_NAME_KEY,
+        Property.IndexScope, Property.PrivateIndex);
+
     /**
      * Sometimes, the default mapping exists and an actual mapping is not created yet (introduced),
      * in this case, we want to return the default mapping in case it has some default mapping definitions.