Avoid warnings for non-system indexes using `fast_refresh` (#124294)

* Update LogsdbIndexModeSettingsProvider.java

* add test

x-pack/plugin/logsdb/src/main/java/org/elasticsearch/xpack/logsdb/LogsdbIndexModeSettingsProvider.java

@@ -309,7 +309,8 @@ final class LogsdbIndexModeSettingsProvider implements IndexSettingProvider {
             .put(indexTemplateAndCreateRequestSettings)
             .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, dummyShards)
             .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, shardReplicas)
-            .put(IndexMetadata.SETTING_INDEX_UUID, UUIDs.randomBase64UUID());
+            .put(IndexMetadata.SETTING_INDEX_UUID, UUIDs.randomBase64UUID())
+            .put(IndexSettings.INDEX_FAST_REFRESH_SETTING.getKey(), false);  // Avoid warnings for non-system indexes.
 
         if (templateIndexMode == IndexMode.TIME_SERIES) {
             finalResolvedSettings.put(IndexSettings.MODE.getKey(), IndexMode.TIME_SERIES);

x-pack/plugin/logsdb/src/test/java/org/elasticsearch/xpack/logsdb/LogsdbIndexModeSettingsProviderTests.java

@@ -1114,7 +1114,10 @@ public class LogsdbIndexModeSettingsProviderTests extends ESTestCase {
     }
 
     public void testSortAndHostNameObject() throws Exception {
-        var settings = Settings.builder().put(IndexSettings.MODE.getKey(), IndexMode.LOGSDB).build();
+        var settings = Settings.builder()
+            .put(IndexSettings.MODE.getKey(), IndexMode.LOGSDB)
+            .put(IndexSettings.INDEX_FAST_REFRESH_SETTING.getKey(), true)
+            .build();
         var mappings = """
             {
                 "_doc": {
@@ -1134,4 +1137,48 @@ public class LogsdbIndexModeSettingsProviderTests extends ESTestCase {
         assertFalse(IndexSettings.LOGSDB_ADD_HOST_NAME_FIELD.get(result));
         assertEquals(1, newMapperServiceCounter.get());
     }
+
+    public void testSortFastRefresh() throws Exception {
+        var settings = Settings.builder()
+            .put(IndexSettings.MODE.getKey(), IndexMode.LOGSDB)
+            .put(IndexSettings.INDEX_FAST_REFRESH_SETTING.getKey(), true)
+            .build();
+        var mappings = """
+            {
+                "_doc": {
+                    "properties": {
+                        "@timestamp": {
+                            "type": "date"
+                        }
+                    }
+                }
+            }
+            """;
+
+        String systemIndex = ".security-profile";
+        Metadata metadata = Metadata.EMPTY_METADATA;
+        var provider = new LogsdbIndexModeSettingsProvider(
+            logsdbLicenseService,
+            Settings.builder().put("cluster.logsdb.enabled", true).build()
+        );
+        provider.init(
+            im -> MapperTestUtils.newMapperService(xContentRegistry(), createTempDir(), im.getSettings(), im.getIndex().getName()),
+            IndexVersion::current,
+            () -> Version.CURRENT,
+            true,
+            true
+        );
+        var additionalIndexSettings = provider.getAdditionalIndexSettings(
+            DataStream.getDefaultBackingIndexName(systemIndex, 0),
+            systemIndex,
+            IndexMode.LOGSDB,
+            metadata.getProject(),
+            Instant.now(),
+            settings,
+            List.of(new CompressedXContent(mappings))
+        );
+
+        Settings result = builder().put(additionalIndexSettings).build();
+        assertTrue(IndexSettings.LOGSDB_SORT_ON_HOST_NAME.get(result));
+    }
 }