Add option to disable closing indices

Closed indices are currently out of scope for snapshots and shard migration,
and can cause issues in managed environments – where closing an index does
not necessarily make sense, as it still consumes the managed environment's storage quota.

This commit adds an option to dynamically disable closing indices via node or cluster settings.

Closes #14168

core/src/main/java/org/elasticsearch/action/admin/indices/close/TransportCloseIndexAction.java

@@ -36,15 +36,15 @@ import org.elasticsearch.node.settings.NodeSettingsService;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 
-import java.util.Arrays;
-
 /**
  * Close index action
  */
-public class TransportCloseIndexAction extends TransportMasterNodeAction<CloseIndexRequest, CloseIndexResponse> {
+public class TransportCloseIndexAction extends TransportMasterNodeAction<CloseIndexRequest, CloseIndexResponse> implements NodeSettingsService.Listener {
 
     private final MetaDataIndexStateService indexStateService;
     private final DestructiveOperations destructiveOperations;
+    private volatile boolean closeIndexEnabled;
+    public static final String SETTING_CLUSTER_INDICES_CLOSE_ENABLE = "cluster.indices.close.enable";
 
     @Inject
     public TransportCloseIndexAction(Settings settings, TransportService transportService, ClusterService clusterService,
@@ -54,6 +54,8 @@ public class TransportCloseIndexAction extends TransportMasterNodeAction<CloseIn
         super(settings, CloseIndexAction.NAME, transportService, clusterService, threadPool, actionFilters, indexNameExpressionResolver, CloseIndexRequest::new);
         this.indexStateService = indexStateService;
         this.destructiveOperations = destructiveOperations;
+        this.closeIndexEnabled = settings.getAsBoolean(SETTING_CLUSTER_INDICES_CLOSE_ENABLE, true);
+        nodeSettingsService.addListener(this);
     }
 
     @Override
@@ -70,6 +72,9 @@ public class TransportCloseIndexAction extends TransportMasterNodeAction<CloseIn
     @Override
     protected void doExecute(CloseIndexRequest request, ActionListener<CloseIndexResponse> listener) {
         destructiveOperations.failDestructive(request.indices());
+        if (closeIndexEnabled == false) {
+            throw new IllegalStateException("closing indices is disabled - set [" + SETTING_CLUSTER_INDICES_CLOSE_ENABLE + ": true] to enable it. NOTE: closed indices consume a significant amount of diskspace");
+        }
         super.doExecute(request, listener);
     }
 
@@ -99,4 +104,13 @@ public class TransportCloseIndexAction extends TransportMasterNodeAction<CloseIn
             }
         });
     }
+
+    @Override
+    public void onRefreshSettings(Settings settings) {
+        final boolean enable = settings.getAsBoolean(SETTING_CLUSTER_INDICES_CLOSE_ENABLE, this.closeIndexEnabled);
+        if (enable != this.closeIndexEnabled) {
+            logger.info("updating [{}] from [{}] to [{}]", SETTING_CLUSTER_INDICES_CLOSE_ENABLE, this.closeIndexEnabled, enable);
+            this.closeIndexEnabled = enable;
+        }
+    }
 }

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

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.cluster;
 
+import org.elasticsearch.action.admin.indices.close.TransportCloseIndexAction;
 import org.elasticsearch.action.support.DestructiveOperations;
 import org.elasticsearch.cluster.action.index.MappingUpdatedAction;
 import org.elasticsearch.cluster.action.index.NodeIndexDeletedAction;
@@ -203,6 +204,7 @@ public class ClusterModule extends AbstractModule {
         registerClusterDynamicSetting(TransportService.SETTING_TRACE_LOG_INCLUDE + ".*", Validator.EMPTY);
         registerClusterDynamicSetting(TransportService.SETTING_TRACE_LOG_EXCLUDE, Validator.EMPTY);
         registerClusterDynamicSetting(TransportService.SETTING_TRACE_LOG_EXCLUDE + ".*", Validator.EMPTY);
+        registerClusterDynamicSetting(TransportCloseIndexAction.SETTING_CLUSTER_INDICES_CLOSE_ENABLE, Validator.BOOLEAN);
     }
 
     private void registerBuiltinIndexSettings() {

core/src/test/java/org/elasticsearch/indices/state/CloseIndexDisableCloseAllIT.java

@@ -21,7 +21,9 @@ package org.elasticsearch.indices.state;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
 import org.elasticsearch.action.admin.cluster.state.ClusterStateResponse;
 import org.elasticsearch.action.admin.indices.close.CloseIndexResponse;
+import org.elasticsearch.action.admin.indices.close.TransportCloseIndexAction;
 import org.elasticsearch.action.support.DestructiveOperations;
+import org.elasticsearch.client.Client;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.test.ESIntegTestCase;
@@ -86,6 +88,20 @@ public class CloseIndexDisableCloseAllIT extends ESIntegTestCase {
         CloseIndexResponse closeIndexResponse = client().admin().indices().prepareClose("test3", "test2").execute().actionGet();
         assertThat(closeIndexResponse.isAcknowledged(), equalTo(true));
         assertIndexIsClosed("test2", "test3");
+
+        // disable closing
+        Client client = client();
+        createIndex("test_no_close");
+        healthResponse = client.admin().cluster().prepareHealth().setWaitForGreenStatus().execute().actionGet();
+        assertThat(healthResponse.isTimedOut(), equalTo(false));
+        client().admin().cluster().prepareUpdateSettings().setTransientSettings(Settings.builder().put(TransportCloseIndexAction.SETTING_CLUSTER_INDICES_CLOSE_ENABLE, false)).get();
+
+        try {
+            client.admin().indices().prepareClose("test_no_close").execute().actionGet();
+            fail("exception expected");
+        } catch (IllegalStateException ex) {
+            assertEquals(ex.getMessage(), "closing indices is disabled - set [cluster.indices.close.enable: true] to enable it. NOTE: closed indices consume a significant amount of diskspace");
+        }
     }
 
     private void assertIndexIsClosed(String... indices) {

docs/reference/indices/open-close.asciidoc

@@ -26,4 +26,8 @@ or specifying patterns that identify them all (e.g. `*`).
 
 Identifying indices via wildcards or `_all` can be disabled by setting the
 `action.destructive_requires_name` flag in the config file to `true`.
-This setting can also be changed via the cluster update settings api.
+This setting can also be changed via the cluster update settings api.
+
+Closed indices consume a significant amount of disk-space which can cause problems
+issues in managed environments. Closing indices can be disabled via the cluster settings
+API by setting `cluster.indices.close.enable` to `false`. The default is `true`.