modify based on comments

Author: ruai0511

plugins/workload-management/src/main/java/org/opensearch/plugin/wlm/WlmModeManager.java

@@ -0,0 +1,63 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.plugin.wlm;
+
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.wlm.WlmMode;
+import org.opensearch.wlm.WorkloadManagementSettings;
+
+/**
+ * Central manager for maintaining the current WLM mode with updates from cluster settings.
+ */
+public class WlmModeManager {
+
+    private volatile WlmMode wlmMode;
+
+    /**
+     * Constructor to initialize and register listener for WLM mode changes.
+     * @param settings OpenSearch settings
+     * @param clusterSettings Cluster settings to register update listener
+     */
+    public WlmModeManager(Settings settings, ClusterSettings clusterSettings) {
+        this.wlmMode = WorkloadManagementSettings.WLM_MODE_SETTING.get(settings);
+        clusterSettings.addSettingsUpdateConsumer(WorkloadManagementSettings.WLM_MODE_SETTING, this::setWlmMode);
+    }
+
+    /**
+     * Check if WLM mode is ENABLED or MONITOR_ONLY.
+     * Throws an IllegalStateException if WLM mode is DISABLED.
+     * @param operationDescription A short text describing the operation, e.g. "create workload group".
+     */
+    public void verifyWlmNotDisabled(String operationDescription) {
+        if (wlmMode == WlmMode.DISABLED) {
+            throw new IllegalStateException(
+                "Cannot "
+                    + operationDescription
+                    + " because workload management mode is DISABLED. "
+                    + "To enable this feature, set [wlm.workload_group.mode] to ENABLED or MONITOR_ONLY in cluster settings."
+            );
+        }
+    }
+
+    /**
+     * Set the latest WLM mode.
+     * @param mode The wlm mode to set
+     */
+    void setWlmMode(WlmMode mode) {
+        this.wlmMode = mode;
+    }
+
+    /**
+     * Get the latest WLM mode.
+     */
+    public WlmMode getWlmMode() {
+        return wlmMode;
+    }
+}

plugins/workload-management/src/main/java/org/opensearch/plugin/wlm/WorkloadManagementPlugin.java

@@ -68,7 +68,6 @@
 import org.opensearch.transport.TransportService;
 import org.opensearch.transport.client.Client;
 import org.opensearch.watcher.ResourceWatcherService;
-import org.opensearch.wlm.WorkloadManagementSettings;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -92,7 +91,7 @@ public class WorkloadManagementPlugin extends Plugin implements ActionPlugin, Sy
     private static FeatureType featureType;
     private static RulePersistenceService rulePersistenceService;
     private static RuleRoutingService ruleRoutingService;
-    private WorkloadManagementSettings workloadManagementSettings;
+    private WlmModeManager wlmModeManager;
     private AutoTaggingActionFilter autoTaggingActionFilter;
 
     /**
@@ -114,7 +113,7 @@ public Collection<Object> createComponents(
         IndexNameExpressionResolver indexNameExpressionResolver,
         Supplier<RepositoriesService> repositoriesServiceSupplier
     ) {
-        workloadManagementSettings = new WorkloadManagementSettings(environment.settings(), clusterService.getClusterSettings());
+        wlmModeManager = new WlmModeManager(clusterService.getSettings(), clusterService.getClusterSettings());
         featureType = new WorkloadGroupFeatureType(new WorkloadGroupFeatureValueValidator(clusterService));
         RuleEntityParser parser = new XContentRuleParser(featureType);
         AttributeValueStoreFactory attributeValueStoreFactory = new AttributeValueStoreFactory(
@@ -135,16 +134,14 @@ public Collection<Object> createComponents(
         RefreshBasedSyncMechanism refreshMechanism = new RefreshBasedSyncMechanism(
             threadPool,
             clusterService.getSettings(),
-            clusterService.getClusterSettings(),
-            parser,
-            ruleProcessingService,
             featureType,
             rulePersistenceService,
-            new RuleEventClassifier(Collections.emptySet(), ruleProcessingService)
+            new RuleEventClassifier(Collections.emptySet(), ruleProcessingService),
+            wlmModeManager
         );
 
         autoTaggingActionFilter = new AutoTaggingActionFilter(ruleProcessingService, threadPool);
-        return List.of(refreshMechanism, workloadManagementSettings);
+        return List.of(refreshMechanism);
     }
 
     @Override
@@ -184,10 +181,10 @@ public List<RestHandler> getRestHandlers(
         Supplier<DiscoveryNodes> nodesInCluster
     ) {
         return List.of(
-            new RestCreateWorkloadGroupAction(workloadManagementSettings),
+            new RestCreateWorkloadGroupAction(wlmModeManager),
             new RestGetWorkloadGroupAction(),
-            new RestDeleteWorkloadGroupAction(workloadManagementSettings),
-            new RestUpdateWorkloadGroupAction(workloadManagementSettings)
+            new RestDeleteWorkloadGroupAction(wlmModeManager),
+            new RestUpdateWorkloadGroupAction(wlmModeManager)
         );
     }
 

plugins/workload-management/src/main/java/org/opensearch/plugin/wlm/rest/RestCreateWorkloadGroupAction.java

@@ -11,6 +11,7 @@
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentParser;
+import org.opensearch.plugin.wlm.WlmModeManager;
 import org.opensearch.plugin.wlm.action.CreateWorkloadGroupAction;
 import org.opensearch.plugin.wlm.action.CreateWorkloadGroupRequest;
 import org.opensearch.plugin.wlm.action.CreateWorkloadGroupResponse;
@@ -21,8 +22,6 @@
 import org.opensearch.rest.RestResponse;
 import org.opensearch.rest.action.RestResponseListener;
 import org.opensearch.transport.client.node.NodeClient;
-import org.opensearch.wlm.WlmMode;
-import org.opensearch.wlm.WorkloadManagementSettings;
 
 import java.io.IOException;
 import java.util.List;
@@ -37,14 +36,14 @@
  */
 public class RestCreateWorkloadGroupAction extends BaseRestHandler {
 
-    private final WorkloadManagementSettings workloadManagementSettings;
+    private final WlmModeManager wlmModeManager;
 
     /**
      * Constructor for RestCreateWorkloadGroupAction
-     * @param workloadManagementSettings the WorkloadManagementSettings instance to access the current WLM mode
+     * @param wlmModeManager the WlmModeManager to access the current WLM mode
      */
-    public RestCreateWorkloadGroupAction(WorkloadManagementSettings workloadManagementSettings) {
-        this.workloadManagementSettings = workloadManagementSettings;
+    public RestCreateWorkloadGroupAction(WlmModeManager wlmModeManager) {
+        this.wlmModeManager = wlmModeManager;
     }
 
     @Override
@@ -62,9 +61,7 @@ public List<Route> routes() {
 
     @Override
     protected RestChannelConsumer prepareRequest(RestRequest request, NodeClient client) throws IOException {
-        if (workloadManagementSettings.getWlmMode() == WlmMode.DISABLED) {
-            throw new IllegalStateException("Workload management mode is DISABLED. Cannot create workload group.");
-        }
+        wlmModeManager.verifyWlmNotDisabled("create workload group");
         try (XContentParser parser = request.contentParser()) {
             CreateWorkloadGroupRequest createWorkloadGroupRequest = CreateWorkloadGroupRequest.fromXContent(parser);
             return channel -> client.execute(

plugins/workload-management/src/main/java/org/opensearch/plugin/wlm/rest/RestDeleteWorkloadGroupAction.java

@@ -8,14 +8,13 @@
 
 package org.opensearch.plugin.wlm.rest;
 
+import org.opensearch.plugin.wlm.WlmModeManager;
 import org.opensearch.plugin.wlm.action.DeleteWorkloadGroupAction;
 import org.opensearch.plugin.wlm.action.DeleteWorkloadGroupRequest;
 import org.opensearch.rest.BaseRestHandler;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.rest.action.RestToXContentListener;
 import org.opensearch.transport.client.node.NodeClient;
-import org.opensearch.wlm.WlmMode;
-import org.opensearch.wlm.WorkloadManagementSettings;
 
 import java.io.IOException;
 import java.util.List;
@@ -29,14 +28,14 @@
  */
 public class RestDeleteWorkloadGroupAction extends BaseRestHandler {
 
-    private final WorkloadManagementSettings workloadManagementSettings;
+    private final WlmModeManager wlmModeManager;
 
     /**
      * Constructor for RestDeleteWorkloadGroupAction
-     * @param workloadManagementSettings the WorkloadManagementSettings instance to access the current WLM mode
+     * @param wlmModeManager the WlmModeManager to access the current WLM mode
      */
-    public RestDeleteWorkloadGroupAction(WorkloadManagementSettings workloadManagementSettings) {
-        this.workloadManagementSettings = workloadManagementSettings;
+    public RestDeleteWorkloadGroupAction(WlmModeManager wlmModeManager) {
+        this.wlmModeManager = wlmModeManager;
     }
 
     @Override
@@ -54,10 +53,7 @@ public List<Route> routes() {
 
     @Override
     protected RestChannelConsumer prepareRequest(RestRequest request, NodeClient client) throws IOException {
-        if (workloadManagementSettings.getWlmMode() == WlmMode.DISABLED) {
-            throw new IllegalStateException("Workload management mode is DISABLED. Cannot delete workload group.");
-        }
-
+        wlmModeManager.verifyWlmNotDisabled("delete workload group");
         DeleteWorkloadGroupRequest deleteWorkloadGroupRequest = new DeleteWorkloadGroupRequest(request.param("name"));
         deleteWorkloadGroupRequest.clusterManagerNodeTimeout(
             request.paramAsTime("cluster_manager_timeout", deleteWorkloadGroupRequest.clusterManagerNodeTimeout())

plugins/workload-management/src/main/java/org/opensearch/plugin/wlm/rest/RestUpdateWorkloadGroupAction.java

@@ -8,10 +8,10 @@
 
 package org.opensearch.plugin.wlm.rest;
 
-import org.opensearch.common.inject.Inject;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentParser;
+import org.opensearch.plugin.wlm.WlmModeManager;
 import org.opensearch.plugin.wlm.action.UpdateWorkloadGroupAction;
 import org.opensearch.plugin.wlm.action.UpdateWorkloadGroupRequest;
 import org.opensearch.plugin.wlm.action.UpdateWorkloadGroupResponse;
@@ -22,8 +22,6 @@
 import org.opensearch.rest.RestResponse;
 import org.opensearch.rest.action.RestResponseListener;
 import org.opensearch.transport.client.node.NodeClient;
-import org.opensearch.wlm.WlmMode;
-import org.opensearch.wlm.WorkloadManagementSettings;
 
 import java.io.IOException;
 import java.util.List;
@@ -38,15 +36,14 @@
  */
 public class RestUpdateWorkloadGroupAction extends BaseRestHandler {
 
-    private final WorkloadManagementSettings workloadManagementSettings;
+    private final WlmModeManager wlmModeManager;
 
     /**
      * Constructor for RestUpdateWorkloadGroupAction
-     * @param workloadManagementSettings the WorkloadManagementSettings instance to access the current WLM mode
+     * @param wlmModeManager the WlmModeManager to access the current WLM mode
      */
-    @Inject
-    public RestUpdateWorkloadGroupAction(WorkloadManagementSettings workloadManagementSettings) {
-        this.workloadManagementSettings = workloadManagementSettings;
+    public RestUpdateWorkloadGroupAction(WlmModeManager wlmModeManager) {
+        this.wlmModeManager = wlmModeManager;
     }
 
     @Override
@@ -64,9 +61,7 @@ public List<Route> routes() {
 
     @Override
     protected RestChannelConsumer prepareRequest(RestRequest request, NodeClient client) throws IOException {
-        if (workloadManagementSettings.getWlmMode() == WlmMode.DISABLED) {
-            throw new IllegalStateException("Workload management mode is DISABLED. Cannot update workload group.");
-        }
+        wlmModeManager.verifyWlmNotDisabled("update workload group");
         try (XContentParser parser = request.contentParser()) {
             UpdateWorkloadGroupRequest updateWorkloadGroupRequest = UpdateWorkloadGroupRequest.fromXContent(parser, request.param("name"));
             return channel -> client.execute(

plugins/workload-management/src/main/java/org/opensearch/plugin/wlm/rule/sync/RefreshBasedSyncMechanism.java

@@ -11,15 +11,13 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.opensearch.common.lifecycle.AbstractLifecycleComponent;
-import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.core.action.ActionListener;
+import org.opensearch.plugin.wlm.WlmModeManager;
 import org.opensearch.plugin.wlm.rule.sync.detect.RuleEvent;
 import org.opensearch.plugin.wlm.rule.sync.detect.RuleEventClassifier;
-import org.opensearch.rule.InMemoryRuleProcessingService;
-import org.opensearch.rule.RuleEntityParser;
 import org.opensearch.rule.RulePersistenceService;
 import org.opensearch.rule.action.GetRuleRequest;
 import org.opensearch.rule.action.GetRuleResponse;
@@ -28,7 +26,6 @@
 import org.opensearch.threadpool.Scheduler;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.wlm.WlmMode;
-import org.opensearch.wlm.WorkloadManagementSettings;
 
 import java.io.IOException;
 import java.util.Collections;
@@ -65,12 +62,10 @@ public class RefreshBasedSyncMechanism extends AbstractLifecycleComponent {
     private final ThreadPool threadPool;
     private long refreshInterval;
     private volatile Scheduler.Cancellable scheduledFuture;
-    private final RuleEntityParser parser;
-    private final InMemoryRuleProcessingService ruleProcessingService;
     private final RulePersistenceService rulePersistenceService;
     private final RuleEventClassifier ruleEventClassifier;
     private final FeatureType featureType;
-    private WlmMode wlmMode;
+    private final WlmModeManager wlmModeManager;
     // This var keeps the Rules which were present during last run of this service
     private Set<Rule> lastRunIndexedRules;
     private static final Logger logger = LogManager.getLogger(RefreshBasedSyncMechanism.class);
@@ -80,41 +75,34 @@ public class RefreshBasedSyncMechanism extends AbstractLifecycleComponent {
      *
      * @param threadPool
      * @param settings
-     * @param clusterSettings
-     * @param parser
-     * @param ruleProcessingService
      * @param featureType
      * @param rulePersistenceService
      * @param ruleEventClassifier
+     * @param wlmModeManager
      */
     public RefreshBasedSyncMechanism(
         ThreadPool threadPool,
         Settings settings,
-        ClusterSettings clusterSettings,
-        RuleEntityParser parser,
-        InMemoryRuleProcessingService ruleProcessingService,
         FeatureType featureType,
         RulePersistenceService rulePersistenceService,
-        RuleEventClassifier ruleEventClassifier
+        RuleEventClassifier ruleEventClassifier,
+        WlmModeManager wlmModeManager
     ) {
         this.threadPool = threadPool;
         refreshInterval = RULE_SYNC_REFRESH_INTERVAL_SETTING.get(settings);
-        this.parser = parser;
-        this.ruleProcessingService = ruleProcessingService;
         this.featureType = featureType;
         this.rulePersistenceService = rulePersistenceService;
         this.lastRunIndexedRules = new HashSet<>();
         this.ruleEventClassifier = ruleEventClassifier;
-        wlmMode = WorkloadManagementSettings.WLM_MODE_SETTING.get(settings);
-        clusterSettings.addSettingsUpdateConsumer(WorkloadManagementSettings.WLM_MODE_SETTING, this::setWlmMode);
+        this.wlmModeManager = wlmModeManager;
     }
 
     /**
      * synchronized check is needed in case two scheduled runs happen concurrently though highly improbable
      * but theoretically possible
      */
     synchronized void doRun() {
-        if (wlmMode != WlmMode.ENABLED) {
+        if (wlmModeManager.getWlmMode() != WlmMode.ENABLED) {
             return;
         }
 
@@ -161,8 +149,4 @@ protected void doClose() throws IOException {
             scheduledFuture.cancel();
         }
     }
-
-    void setWlmMode(WlmMode mode) {
-        this.wlmMode = mode;
-    }
 }