Improve TbMsgGeneratorNode to be executed in singleton mode

@@ -57,6 +57,7 @@ import org.thingsboard.server.service.script.RuleNodeJsScriptEngine;
 import scala.concurrent.duration.Duration;
 
 import java.util.Collections;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
@@ -102,6 +103,12 @@ class DefaultTbContext implements TbContext {
         scheduleMsgWithDelay(new RuleNodeToSelfMsg(msg), delayMs, nodeCtx.getSelfActor());
     }
 
+    @Override
+    public boolean isLocalEntity(EntityId entityId) {
+        Optional<ServerAddress> address = mainCtx.getRoutingService().resolveById(entityId);
+        return !address.isPresent();
+    }
+
     private void scheduleMsgWithDelay(Object msg, long delayInMs, ActorRef target) {
         mainCtx.getScheduler().scheduleOnce(Duration.create(delayInMs, TimeUnit.MILLISECONDS), target, msg, mainCtx.getActorSystem().dispatcher(), nodeCtx.getSelfActor());
     }

@@ -83,7 +83,9 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
 
     @Override
     public void onClusterEventMsg(ClusterEventMsg msg) {
-
+        if (tbNode != null) {
+            tbNode.onClusterEventMsg(defaultCtx, msg);
+        }
     }
 
     public void onRuleToSelfMsg(RuleNodeToSelfMsg msg) throws Exception {

@@ -51,6 +51,8 @@ public interface TbContext {
 
     void tellSelf(TbMsg msg, long delayMs);
 
+    boolean isLocalEntity(EntityId entityId);
+
     void tellFailure(TbMsg msg, Throwable th);
 
     void updateSelf(RuleNode self);

@@ -16,6 +16,7 @@
 package org.thingsboard.rule.engine.api;
 
 import org.thingsboard.server.common.msg.TbMsg;
+import org.thingsboard.server.common.msg.cluster.ClusterEventMsg;
 
 import java.util.concurrent.ExecutionException;
 
@@ -30,4 +31,6 @@ public interface TbNode {
 
     void destroy();
 
+    default void onClusterEventMsg(TbContext ctx, ClusterEventMsg msg) {}
+
 }

@@ -25,6 +25,7 @@ import org.thingsboard.server.common.data.id.EntityIdFactory;
 import org.thingsboard.server.common.data.plugin.ComponentType;
 import org.thingsboard.server.common.msg.TbMsg;
 import org.thingsboard.server.common.msg.TbMsgMetaData;
+import org.thingsboard.server.common.msg.cluster.ClusterEventMsg;
 
 import java.util.UUID;
 import java.util.concurrent.TimeUnit;
@@ -56,6 +57,7 @@ public class TbMsgGeneratorNode implements TbNode {
     private EntityId originatorId;
     private UUID nextTickId;
     private TbMsg prevMsg;
+    private volatile boolean initialized;
 
     @Override
     public void init(TbContext ctx, TbNodeConfiguration configuration) throws TbNodeException {
@@ -66,21 +68,42 @@ public class TbMsgGeneratorNode implements TbNode {
         } else {
             originatorId = ctx.getSelfId();
         }
-        this.jsEngine = ctx.createJsScriptEngine(config.getJsScript(), "prevMsg", "prevMetadata", "prevMsgType");
-        scheduleTickMsg(ctx);
+        updateGeneratorState(ctx);
+    }
+
+    @Override
+    public void onClusterEventMsg(TbContext ctx, ClusterEventMsg msg) {
+        updateGeneratorState(ctx);
+    }
+
+    private void updateGeneratorState(TbContext ctx) {
+        if (ctx.isLocalEntity(originatorId)) {
+            if (!initialized) {
+                initialized = true;
+                this.jsEngine = ctx.createJsScriptEngine(config.getJsScript(), "prevMsg", "prevMetadata", "prevMsgType");
+                scheduleTickMsg(ctx);
+            }
+        } else if (initialized) {
+            initialized = false;
+            destroy();
+        }
     }
 
     @Override
     public void onMsg(TbContext ctx, TbMsg msg) {
-        if (msg.getType().equals(TB_MSG_GENERATOR_NODE_MSG) && msg.getId().equals(nextTickId)) {
+        if (initialized && msg.getType().equals(TB_MSG_GENERATOR_NODE_MSG) && msg.getId().equals(nextTickId)) {
             withCallback(generate(ctx),
                     m -> {
-                        ctx.tellNext(m, SUCCESS);
-                        scheduleTickMsg(ctx);
+                        if (initialized) {
+                            ctx.tellNext(m, SUCCESS);
+                            scheduleTickMsg(ctx);
+                        }
                     },
                     t -> {
-                        ctx.tellFailure(msg, t);
-                        scheduleTickMsg(ctx);
+                        if (initialized) {
+                            ctx.tellFailure(msg, t);
+                            scheduleTickMsg(ctx);
+                        }
                     });
         }
     }
@@ -102,8 +125,10 @@ public class TbMsgGeneratorNode implements TbNode {
             if (prevMsg == null) {
                 prevMsg = ctx.newMsg("", originatorId, new TbMsgMetaData(), "{}");
             }
-            TbMsg generated = jsEngine.executeGenerate(prevMsg);
-            prevMsg = ctx.newMsg(generated.getType(), originatorId, generated.getMetaData(), generated.getData());
+            if (initialized) {
+                TbMsg generated = jsEngine.executeGenerate(prevMsg);
+                prevMsg = ctx.newMsg(generated.getType(), originatorId, generated.getMetaData(), generated.getData());
+            }
             return prevMsg;
         });
     }
@@ -113,6 +138,7 @@ public class TbMsgGeneratorNode implements TbNode {
         prevMsg = null;
         if (jsEngine != null) {
             jsEngine.destroy();
+            jsEngine = null;
         }
     }
 }