[RollupV2] Move rollup metadata to field mappings (#69921)

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 and 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;
@@ -65,7 +64,6 @@
 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;
@@ -135,9 +133,6 @@ 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;
@@ -162,10 +157,6 @@ 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

@@ -570,6 +570,13 @@ 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);
+
     ImmutableOpenMap<String, DiffableStringMap> getCustomData() {
         return this.customData;
     }