Ignore archived settings on update

CHANGELOG.md

@@ -94,6 +94,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Field-level ignore_malformed should override index-level setting ([#18706](https://github.com/opensearch-project/OpenSearch/pull/18706))
 - Fixed Staggered merge -  load average replace with AverageTrackers, some Default thresholds modified ([#18666](https://github.com/opensearch-project/OpenSearch/pull/18666))
 - Use `new SecureRandom()` to avoid blocking ([18729](https://github.com/opensearch-project/OpenSearch/issues/18729))
+- Ignore archived settings on update ([#8714](https://github.com/opensearch-project/OpenSearch/issues/8714))
 - Ignore awareness attributes when a custom preference string is included with a search request ([#18848](https://github.com/opensearch-project/OpenSearch/pull/18848))
 - Use ScoreDoc instead of FieldDoc when creating TopScoreDocCollectorManager to avoid unnecessary conversion ([#18802](https://github.com/opensearch-project/OpenSearch/pull/18802))
 - Fix leafSorter optimization for ReadOnlyEngine and NRTReplicationEngine ([#18639](https://github.com/opensearch-project/OpenSearch/pull/18639))

server/src/internalClusterTest/java/org/opensearch/indices/settings/ArchivedIndexSettingsIT.java

@@ -88,6 +88,14 @@ public void testArchiveSettings() throws Exception {
             startsWith("Can't update non dynamic settings [[archived.index.dummy]] for open indices [[test")
         );
 
+        // Verify that a random unrelated setting can be updated when archived settings are present.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("test")
+            .setSettings(Settings.builder().put("index.max_terms_count", 1024).build())
+            .execute()
+            .actionGet();
+
         // close the index.
         client().admin().indices().prepareClose("test").get();
 

server/src/main/java/org/opensearch/cluster/metadata/MetadataUpdateSettingsService.java

@@ -357,7 +357,9 @@ public ClusterState execute(ClusterState currentState) {
                                 Settings finalSettings = indexSettings.build();
                                 indexScopedSettings.validate(
                                     finalSettings.filter(k -> indexScopedSettings.isPrivateSetting(k) == false),
-                                    true
+                                    true, // validateDependencies
+                                    false, // ignorePrivateSettings
+                                    true  // ignoreArchivedSettings
                                 );
                                 metadataBuilder.put(IndexMetadata.builder(indexMetadata).settings(finalSettings));
                             }
@@ -389,9 +391,9 @@ public ClusterState execute(ClusterState currentState) {
                                 Settings finalSettings = indexSettings.build();
                                 indexScopedSettings.validate(
                                     finalSettings.filter(k -> indexScopedSettings.isPrivateSetting(k) == false),
-                                    true,
-                                    false,
-                                    true
+                                    true, // validateDependencies
+                                    false, // ignorePrivateSettings
+                                    true  // ignoreArchivedSettings
                                 );
                                 metadataBuilder.put(IndexMetadata.builder(indexMetadata).settings(finalSettings));
                             }