From b20057004be642ed2597eafbaf22793e32a9de99 Mon Sep 17 00:00:00 2001
From: Andrii Shvaika <ashvayka@thingsboard.io>
Date: Tue, 18 Apr 2023 17:09:34 +0300
Subject: [PATCH 01/11] Singleton rule node implementation

---
 .../actors/ruleChain/RuleChainActorMessageProcessor.java   | 1 +
 .../actors/ruleChain/RuleNodeActorMessageProcessor.java    | 7 ++++---
 .../org/thingsboard/server/common/data/rule/RuleNode.java  | 5 ++++-
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleChainActorMessageProcessor.java b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleChainActorMessageProcessor.java
index 0e1e25bd27..12ea2fd651 100644
--- a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleChainActorMessageProcessor.java
+++ b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleChainActorMessageProcessor.java
@@ -388,6 +388,7 @@ public class RuleChainActorMessageProcessor extends ComponentMsgProcessor<RuleCh
 
     private void pushMsgToNode(RuleNodeCtx nodeCtx, TbMsg msg, String fromRelationType) {
         if (nodeCtx != null) {
+            //TODO: analyze that singleton flag and execute putToQueue if needed.
             nodeCtx.getSelfActor().tell(new RuleChainToRuleNodeMsg(new DefaultTbContext(systemContext, ruleChainName, nodeCtx), msg, fromRelationType));
         } else {
             log.error("[{}][{}] RuleNodeCtx is empty", entityId, ruleChainName);
diff --git a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
index a6049ce8f2..6174027d38 100644
--- a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
+++ b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
@@ -39,11 +39,10 @@ import org.thingsboard.server.common.stats.TbApiUsageReportClient;
 public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNodeId> {
 
     private final String ruleChainName;
-    private final TbActorRef self;
     private final TbApiUsageReportClient apiUsageClient;
+    private final DefaultTbContext defaultCtx;
     private RuleNode ruleNode;
     private TbNode tbNode;
-    private DefaultTbContext defaultCtx;
     private RuleNodeInfo info;
 
     RuleNodeActorMessageProcessor(TenantId tenantId, String ruleChainName, RuleNodeId ruleNodeId, ActorSystemContext systemContext
@@ -51,7 +50,6 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
         super(systemContext, tenantId, ruleNodeId);
         this.apiUsageClient = systemContext.getApiUsageClient();
         this.ruleChainName = ruleChainName;
-        this.self = self;
         this.ruleNode = systemContext.getRuleChainService().findRuleNodeById(tenantId, entityId);
         this.defaultCtx = new DefaultTbContext(systemContext, ruleChainName, new RuleNodeCtx(tenantId, parent, self, ruleNode));
         this.info = new RuleNodeInfo(ruleNodeId, ruleChainName, ruleNode != null ? ruleNode.getName() : "Unknown");
@@ -59,6 +57,7 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
 
     @Override
     public void start(TbActorCtx context) throws Exception {
+        //TODO: do not start the node if singleton
         tbNode = initComponent(ruleNode);
         if (tbNode != null) {
             state = ComponentLifecycleState.ACTIVE;
@@ -95,12 +94,14 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
 
     @Override
     public void onPartitionChangeMsg(PartitionChangeMsg msg) {
+        //TODO: start the node
         if (tbNode != null) {
             tbNode.onPartitionChangeMsg(defaultCtx, msg);
         }
     }
 
     public void onRuleToSelfMsg(RuleNodeToSelfMsg msg) throws Exception {
+        // TODO: check that the rule node is singleton and use putToQueue
         checkComponentStateActive(msg.getMsg());
         TbMsg tbMsg = msg.getMsg();
         int ruleNodeCount = tbMsg.getAndIncrementRuleNodeCounter();
diff --git a/common/data/src/main/java/org/thingsboard/server/common/data/rule/RuleNode.java b/common/data/src/main/java/org/thingsboard/server/common/data/rule/RuleNode.java
index 32d396725b..e6041c94f7 100644
--- a/common/data/src/main/java/org/thingsboard/server/common/data/rule/RuleNode.java
+++ b/common/data/src/main/java/org/thingsboard/server/common/data/rule/RuleNode.java
@@ -48,7 +48,9 @@ public class RuleNode extends SearchTextBasedWithAdditionalInfo<RuleNodeId> impl
     private String name;
     @ApiModelProperty(position = 6, value = "Enable/disable debug. ", example = "false")
     private boolean debugMode;
-    @ApiModelProperty(position = 7, value = "JSON with the rule node configuration. Structure depends on the rule node implementation.", dataType = "com.fasterxml.jackson.databind.JsonNode")
+    @ApiModelProperty(position = 7, value = "Enable/disable singleton mode. ", example = "false")
+    private boolean singletonMode;
+    @ApiModelProperty(position = 8, value = "JSON with the rule node configuration. Structure depends on the rule node implementation.", dataType = "com.fasterxml.jackson.databind.JsonNode")
     private transient JsonNode configuration;
     @JsonIgnore
     private byte[] configurationBytes;
@@ -69,6 +71,7 @@ public class RuleNode extends SearchTextBasedWithAdditionalInfo<RuleNodeId> impl
         this.type = ruleNode.getType();
         this.name = ruleNode.getName();
         this.debugMode = ruleNode.isDebugMode();
+        this.singletonMode = ruleNode.isSingletonMode();
         this.setConfiguration(ruleNode.getConfiguration());
         this.externalId = ruleNode.getExternalId();
     }

From 3261cf4fe3f80a2d3ce62c44d00ede72b9bd81ca Mon Sep 17 00:00:00 2001
From: YevhenBondarenko <ybondarenko@thingsboard.io>
Date: Thu, 20 Apr 2023 16:07:14 +0200
Subject: [PATCH 02/11] implemented rule node singleton mode

---
 .../main/data/upgrade/3.4.4/schema_update.sql |  13 ++
 .../server/actors/ActorSystemContext.java     |   5 +
 .../RuleNodeActorMessageProcessor.java        | 111 ++++++++++++------
 .../AnnotationComponentDiscoveryService.java  |   1 +
 .../data/plugin/ComponentDescriptor.java      |   2 +
 .../plugin/ComponentSingletonSupport.java     |  22 ++++
 .../server/dao/model/ModelConstants.java      |   2 +
 .../model/sql/ComponentDescriptorEntity.java  |   7 ++
 .../server/dao/model/sql/RuleNodeEntity.java  |   5 +
 .../thingsboard/rule/engine/api/RuleNode.java |   3 +
 .../rule/engine/mqtt/TbMqttNode.java          |   2 +
 .../engine/mqtt/azure/TbAzureIotHubNode.java  |   5 +-
 .../import-export/import-export.service.ts    |   1 +
 .../rule-node-details.component.html          |   3 +
 .../rulechain/rule-node-details.component.ts  |   6 +
 .../rulechain/rulechain-page.component.ts     |  11 +-
 .../models/component-descriptor.models.ts     |   7 ++
 .../app/shared/models/rule-chain.models.ts    |   4 +-
 .../src/app/shared/models/rule-node.models.ts |   2 +
 .../assets/locale/locale.constant-en_US.json  |   1 +
 20 files changed, 170 insertions(+), 43 deletions(-)
 create mode 100644 common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentSingletonSupport.java

diff --git a/application/src/main/data/upgrade/3.4.4/schema_update.sql b/application/src/main/data/upgrade/3.4.4/schema_update.sql
index 3776eebc12..e15a9fb9e9 100644
--- a/application/src/main/data/upgrade/3.4.4/schema_update.sql
+++ b/application/src/main/data/upgrade/3.4.4/schema_update.sql
@@ -610,3 +610,16 @@ END
 $$;
 
 -- TTL DROP PARTITIONS FUNCTIONS UPDATE END
+
+-- RULE NODE SINGLETON MODE SUPPORT
+
+ALTER TABLE rule_node ADD COLUMN IF NOT EXISTS singleton_mode bool DEFAULT false;
+
+UPDATE rule_node SET singleton_mode = true WHERE type IN ('org.thingsboard.rule.engine.mqtt.azure.TbAzureIotHubNode', 'org.thingsboard.rule.engine.mqtt.TbMqttNode');
+
+ALTER TABLE component_descriptor ADD COLUMN IF NOT EXISTS singleton varchar(255) DEFAULT 'NOT_SUPPORTED';
+
+UPDATE component_descriptor SET singleton = 'SUPPORTED' WHERE name = 'mqtt';
+
+UPDATE component_descriptor SET singleton = 'ONLY_SINGLETON' WHERE name = 'azure iot hub';
+
diff --git a/application/src/main/java/org/thingsboard/server/actors/ActorSystemContext.java b/application/src/main/java/org/thingsboard/server/actors/ActorSystemContext.java
index 26eab30d5d..1f0af4f1d1 100644
--- a/application/src/main/java/org/thingsboard/server/actors/ActorSystemContext.java
+++ b/application/src/main/java/org/thingsboard/server/actors/ActorSystemContext.java
@@ -87,6 +87,7 @@ import org.thingsboard.server.dao.timeseries.TimeseriesService;
 import org.thingsboard.server.dao.user.UserService;
 import org.thingsboard.server.dao.widget.WidgetTypeService;
 import org.thingsboard.server.dao.widget.WidgetsBundleService;
+import org.thingsboard.server.queue.discovery.DiscoveryService;
 import org.thingsboard.server.queue.discovery.PartitionService;
 import org.thingsboard.server.queue.discovery.TbServiceInfoProvider;
 import org.thingsboard.server.common.msg.notification.NotificationRuleProcessor;
@@ -179,6 +180,10 @@ public class ActorSystemContext {
     @Setter
     private ComponentDiscoveryService componentService;
 
+    @Autowired
+    @Getter
+    private DiscoveryService discoveryService;
+
     @Autowired
     @Getter
     private DataDecodingEncodingService encodingService;
diff --git a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
index 6174027d38..223dfa2de2 100644
--- a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
+++ b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
@@ -31,7 +31,10 @@ import org.thingsboard.server.common.msg.TbMsg;
 import org.thingsboard.server.common.msg.queue.PartitionChangeMsg;
 import org.thingsboard.server.common.msg.queue.RuleNodeException;
 import org.thingsboard.server.common.msg.queue.RuleNodeInfo;
+import org.thingsboard.server.common.msg.queue.ServiceType;
+import org.thingsboard.server.common.msg.queue.TopicPartitionInfo;
 import org.thingsboard.server.common.stats.TbApiUsageReportClient;
+import org.thingsboard.server.gen.transport.TransportProtos;
 
 /**
  * @author Andrew Shvayka
@@ -57,29 +60,37 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
 
     @Override
     public void start(TbActorCtx context) throws Exception {
-        //TODO: do not start the node if singleton
-        tbNode = initComponent(ruleNode);
-        if (tbNode != null) {
-            state = ComponentLifecycleState.ACTIVE;
+        if (isMyNode()) {
+            tbNode = initComponent(ruleNode);
+            if (tbNode != null) {
+                state = ComponentLifecycleState.ACTIVE;
+            }
         }
     }
 
     @Override
     public void onUpdate(TbActorCtx context) throws Exception {
-        RuleNode newRuleNode = systemContext.getRuleChainService().findRuleNodeById(tenantId, entityId);
-        this.info = new RuleNodeInfo(entityId, ruleChainName, newRuleNode != null ? newRuleNode.getName() : "Unknown");
-        boolean restartRequired = state != ComponentLifecycleState.ACTIVE ||
-                !(ruleNode.getType().equals(newRuleNode.getType()) && ruleNode.getConfiguration().equals(newRuleNode.getConfiguration()));
-        this.ruleNode = newRuleNode;
-        this.defaultCtx.updateSelf(newRuleNode);
-        if (restartRequired) {
+        if (isMyNode()) {
+            RuleNode newRuleNode = systemContext.getRuleChainService().findRuleNodeById(tenantId, entityId);
+            this.info = new RuleNodeInfo(entityId, ruleChainName, newRuleNode != null ? newRuleNode.getName() : "Unknown");
+            boolean restartRequired = state != ComponentLifecycleState.ACTIVE ||
+                    !(ruleNode.getType().equals(newRuleNode.getType()) && ruleNode.getConfiguration().equals(newRuleNode.getConfiguration()));
+            this.ruleNode = newRuleNode;
+            this.defaultCtx.updateSelf(newRuleNode);
+            if (restartRequired) {
+                if (tbNode != null) {
+                    tbNode.destroy();
+                }
+                try {
+                    start(context);
+                } catch (Exception e) {
+                    throw new TbRuleNodeUpdateException("Failed to update rule node", e);
+                }
+            }
+        } else {
             if (tbNode != null) {
                 tbNode.destroy();
-            }
-            try {
-                start(context);
-            } catch (Exception e) {
-                throw new TbRuleNodeUpdateException("Failed to update rule node", e);
+                tbNode = null;
             }
         }
     }
@@ -93,15 +104,20 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     }
 
     @Override
-    public void onPartitionChangeMsg(PartitionChangeMsg msg) {
-        //TODO: start the node
+    public void onPartitionChangeMsg(PartitionChangeMsg msg) throws Exception {
         if (tbNode != null) {
-            tbNode.onPartitionChangeMsg(defaultCtx, msg);
+            if (!isMyNode()) {
+                tbNode.destroy();
+                tbNode = null;
+            } else {
+                tbNode.onPartitionChangeMsg(defaultCtx, msg);
+            }
+        } else if (isMyNode()) {
+            start(null);
         }
     }
 
     public void onRuleToSelfMsg(RuleNodeToSelfMsg msg) throws Exception {
-        // TODO: check that the rule node is singleton and use putToQueue
         checkComponentStateActive(msg.getMsg());
         TbMsg tbMsg = msg.getMsg();
         int ruleNodeCount = tbMsg.getAndIncrementRuleNodeCounter();
@@ -122,23 +138,27 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     }
 
     void onRuleChainToRuleNodeMsg(RuleChainToRuleNodeMsg msg) throws Exception {
-        msg.getMsg().getCallback().onProcessingStart(info);
-        checkComponentStateActive(msg.getMsg());
-        TbMsg tbMsg = msg.getMsg();
-        int ruleNodeCount = tbMsg.getAndIncrementRuleNodeCounter();
-        int maxRuleNodeExecutionsPerMessage = getTenantProfileConfiguration().getMaxRuleNodeExecsPerMessage();
-        if (maxRuleNodeExecutionsPerMessage == 0 || ruleNodeCount < maxRuleNodeExecutionsPerMessage) {
-            apiUsageClient.report(tenantId, tbMsg.getCustomerId(), ApiUsageRecordKey.RE_EXEC_COUNT);
-            if (ruleNode.isDebugMode()) {
-                systemContext.persistDebugInput(tenantId, entityId, msg.getMsg(), msg.getFromRelationType());
-            }
-            try {
-                tbNode.onMsg(msg.getCtx(), msg.getMsg());
-            } catch (Exception e) {
-                msg.getCtx().tellFailure(msg.getMsg(), e);
-            }
+        if (!isMyNode()) {
+            putToQueue(msg.getMsg());
         } else {
-            tbMsg.getCallback().onFailure(new RuleNodeException("Message is processed by more then " + maxRuleNodeExecutionsPerMessage + " rule nodes!", ruleChainName, ruleNode));
+            msg.getMsg().getCallback().onProcessingStart(info);
+            checkComponentStateActive(msg.getMsg());
+            TbMsg tbMsg = msg.getMsg();
+            int ruleNodeCount = tbMsg.getAndIncrementRuleNodeCounter();
+            int maxRuleNodeExecutionsPerMessage = getTenantProfileConfiguration().getMaxRuleNodeExecsPerMessage();
+            if (maxRuleNodeExecutionsPerMessage == 0 || ruleNodeCount < maxRuleNodeExecutionsPerMessage) {
+                apiUsageClient.report(tenantId, tbMsg.getCustomerId(), ApiUsageRecordKey.RE_EXEC_COUNT);
+                if (ruleNode.isDebugMode()) {
+                    systemContext.persistDebugInput(tenantId, entityId, msg.getMsg(), msg.getFromRelationType());
+                }
+                try {
+                    tbNode.onMsg(msg.getCtx(), msg.getMsg());
+                } catch (Exception e) {
+                    msg.getCtx().tellFailure(msg.getMsg(), e);
+                }
+            } else {
+                tbMsg.getCallback().onFailure(new RuleNodeException("Message is processed by more then " + maxRuleNodeExecutionsPerMessage + " rule nodes!", ruleChainName, ruleNode));
+            }
         }
     }
 
@@ -161,4 +181,23 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     protected RuleNodeException getInactiveException() {
         return new RuleNodeException("Rule Node is not active! Failed to initialize.", ruleChainName, ruleNode);
     }
+
+    private boolean isMyNode() {
+        return systemContext.getDiscoveryService().isMonolith()
+                || !ruleNode.isSingletonMode()
+//                || !ruleNode.getName().equals("singleton")
+                || defaultCtx.isLocalEntity(ruleNode.getId());
+    }
+
+    private void putToQueue(TbMsg source) {
+        TbMsg tbMsg = TbMsg.newMsg(source, source.getQueueName(), source.getRuleChainId(), entityId);
+        TopicPartitionInfo tpi = systemContext.resolve(ServiceType.TB_RULE_ENGINE, tbMsg.getQueueName(), tenantId, entityId);
+        TransportProtos.ToRuleEngineMsg toQueueMsg = TransportProtos.ToRuleEngineMsg.newBuilder()
+                .setTenantIdMSB(tenantId.getId().getMostSignificantBits())
+                .setTenantIdLSB(tenantId.getId().getLeastSignificantBits())
+                .setTbMsg(TbMsg.toByteString(tbMsg))
+                .build();
+        systemContext.getClusterService().pushMsgToRuleEngine(tpi, tbMsg.getId(), toQueueMsg, null);
+        defaultCtx.ack(source);
+    }
 }
diff --git a/application/src/main/java/org/thingsboard/server/service/component/AnnotationComponentDiscoveryService.java b/application/src/main/java/org/thingsboard/server/service/component/AnnotationComponentDiscoveryService.java
index 732d8ce409..bb63f5da4c 100644
--- a/application/src/main/java/org/thingsboard/server/service/component/AnnotationComponentDiscoveryService.java
+++ b/application/src/main/java/org/thingsboard/server/service/component/AnnotationComponentDiscoveryService.java
@@ -155,6 +155,7 @@ public class AnnotationComponentDiscoveryService implements ComponentDiscoverySe
             RuleNode ruleNodeAnnotation = clazz.getAnnotation(RuleNode.class);
             scannedComponent.setName(ruleNodeAnnotation.name());
             scannedComponent.setScope(ruleNodeAnnotation.scope());
+            scannedComponent.setSingleton(ruleNodeAnnotation.singleton());
             NodeDefinition nodeDefinition = prepareNodeDefinition(ruleNodeAnnotation);
             ObjectNode configurationDescriptor = mapper.createObjectNode();
             JsonNode node = mapper.valueToTree(nodeDefinition);
diff --git a/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentDescriptor.java b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentDescriptor.java
index 288801b8d6..9839e34482 100644
--- a/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentDescriptor.java
+++ b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentDescriptor.java
@@ -36,6 +36,8 @@ public class ComponentDescriptor extends SearchTextBased<ComponentDescriptorId>
     @Getter @Setter private ComponentType type;
     @ApiModelProperty(position = 4, value = "Scope of the Rule Node. Always set to 'TENANT', since no rule chains on the 'SYSTEM' level yet.", accessMode = ApiModelProperty.AccessMode.READ_ONLY, allowableValues = "TENANT", example = "TENANT")
     @Getter @Setter private ComponentScope scope;
+    @ApiModelProperty(position = 4, value = "", accessMode = ApiModelProperty.AccessMode.READ_ONLY, allowableValues = "SUPPORTED, NOT_SUPPORTEd, ONLY_SINGLETON", example = "SUPPORTED")
+    @Getter @Setter private ComponentSingletonSupport singleton;
     @Length(fieldName = "name")
     @ApiModelProperty(position = 5, value = "Name of the Rule Node. Taken from the @RuleNode annotation.", accessMode = ApiModelProperty.AccessMode.READ_ONLY, example = "Custom Rule Node")
     @Getter @Setter private String name;
diff --git a/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentSingletonSupport.java b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentSingletonSupport.java
new file mode 100644
index 0000000000..0472f26808
--- /dev/null
+++ b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentSingletonSupport.java
@@ -0,0 +1,22 @@
+/**
+ * Copyright © 2016-2023 The Thingsboard Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.thingsboard.server.common.data.plugin;
+
+public enum ComponentSingletonSupport {
+    SUPPORTED,
+    NOT_SUPPORTED,
+    ONLY_SINGLETON
+}
diff --git a/dao/src/main/java/org/thingsboard/server/dao/model/ModelConstants.java b/dao/src/main/java/org/thingsboard/server/dao/model/ModelConstants.java
index 6197d8f908..7b1df3c4a9 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/model/ModelConstants.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/model/ModelConstants.java
@@ -403,6 +403,7 @@ public class ModelConstants {
     public static final String COMPONENT_DESCRIPTOR_COLUMN_FAMILY_NAME = "component_descriptor";
     public static final String COMPONENT_DESCRIPTOR_TYPE_PROPERTY = "type";
     public static final String COMPONENT_DESCRIPTOR_SCOPE_PROPERTY = "scope";
+    public static final String COMPONENT_DESCRIPTOR_SINGLETON_PROPERTY = "singleton";
     public static final String COMPONENT_DESCRIPTOR_NAME_PROPERTY = "name";
     public static final String COMPONENT_DESCRIPTOR_CLASS_PROPERTY = "clazz";
     public static final String COMPONENT_DESCRIPTOR_CONFIGURATION_DESCRIPTOR_PROPERTY = "configuration_descriptor";
@@ -446,6 +447,7 @@ public class ModelConstants {
     public static final String EVENT_MESSAGE_COLUMN_NAME = "e_message";
 
     public static final String DEBUG_MODE = "debug_mode";
+    public static final String SINGLETON_MODE = "singleton_mode";
 
     /**
      * Cassandra rule chain constants.
diff --git a/dao/src/main/java/org/thingsboard/server/dao/model/sql/ComponentDescriptorEntity.java b/dao/src/main/java/org/thingsboard/server/dao/model/sql/ComponentDescriptorEntity.java
index 10e8bb59d5..47c34e0d58 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/model/sql/ComponentDescriptorEntity.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/model/sql/ComponentDescriptorEntity.java
@@ -23,6 +23,7 @@ import org.hibernate.annotations.TypeDef;
 import org.thingsboard.server.common.data.id.ComponentDescriptorId;
 import org.thingsboard.server.common.data.plugin.ComponentDescriptor;
 import org.thingsboard.server.common.data.plugin.ComponentScope;
+import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
 import org.thingsboard.server.common.data.plugin.ComponentType;
 import org.thingsboard.server.dao.model.BaseSqlEntity;
 import org.thingsboard.server.dao.model.ModelConstants;
@@ -50,6 +51,10 @@ public class ComponentDescriptorEntity extends BaseSqlEntity<ComponentDescriptor
     @Column(name = ModelConstants.COMPONENT_DESCRIPTOR_SCOPE_PROPERTY)
     private ComponentScope scope;
 
+    @Enumerated(EnumType.STRING)
+    @Column(name = ModelConstants.COMPONENT_DESCRIPTOR_SINGLETON_PROPERTY)
+    private ComponentSingletonSupport singleton;
+
     @Column(name = ModelConstants.COMPONENT_DESCRIPTOR_NAME_PROPERTY)
     private String name;
 
@@ -77,6 +82,7 @@ public class ComponentDescriptorEntity extends BaseSqlEntity<ComponentDescriptor
         this.actions = component.getActions();
         this.type = component.getType();
         this.scope = component.getScope();
+        this.singleton = component.getSingleton();
         this.name = component.getName();
         this.clazz = component.getClazz();
         this.configurationDescriptor = component.getConfigurationDescriptor();
@@ -89,6 +95,7 @@ public class ComponentDescriptorEntity extends BaseSqlEntity<ComponentDescriptor
         data.setCreatedTime(createdTime);
         data.setType(type);
         data.setScope(scope);
+        data.setSingleton(singleton);
         data.setName(this.getName());
         data.setClazz(this.getClazz());
         data.setActions(this.getActions());
diff --git a/dao/src/main/java/org/thingsboard/server/dao/model/sql/RuleNodeEntity.java b/dao/src/main/java/org/thingsboard/server/dao/model/sql/RuleNodeEntity.java
index 6ce0e45e21..2dce9fb305 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/model/sql/RuleNodeEntity.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/model/sql/RuleNodeEntity.java
@@ -64,6 +64,9 @@ public class RuleNodeEntity extends BaseSqlEntity<RuleNode> implements SearchTex
     @Column(name = ModelConstants.DEBUG_MODE)
     private boolean debugMode;
 
+    @Column(name = ModelConstants.SINGLETON_MODE)
+    private boolean singletonMode;
+
     @Column(name = ModelConstants.EXTERNAL_ID_PROPERTY)
     private UUID externalId;
 
@@ -81,6 +84,7 @@ public class RuleNodeEntity extends BaseSqlEntity<RuleNode> implements SearchTex
         this.type = ruleNode.getType();
         this.name = ruleNode.getName();
         this.debugMode = ruleNode.isDebugMode();
+        this.singletonMode = ruleNode.isSingletonMode();
         this.searchText = ruleNode.getName();
         this.configuration = ruleNode.getConfiguration();
         this.additionalInfo = ruleNode.getAdditionalInfo();
@@ -109,6 +113,7 @@ public class RuleNodeEntity extends BaseSqlEntity<RuleNode> implements SearchTex
         ruleNode.setType(type);
         ruleNode.setName(name);
         ruleNode.setDebugMode(debugMode);
+        ruleNode.setSingletonMode(singletonMode);
         ruleNode.setConfiguration(configuration);
         ruleNode.setAdditionalInfo(additionalInfo);
         if (externalId != null) {
diff --git a/rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/RuleNode.java b/rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/RuleNode.java
index 5fbd65e711..9fb8bb66c0 100644
--- a/rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/RuleNode.java
+++ b/rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/RuleNode.java
@@ -16,6 +16,7 @@
 package org.thingsboard.rule.engine.api;
 
 import org.thingsboard.server.common.data.plugin.ComponentScope;
+import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
 import org.thingsboard.server.common.data.plugin.ComponentType;
 import org.thingsboard.server.common.data.rule.RuleChainType;
 
@@ -38,6 +39,8 @@ public @interface RuleNode {
 
     Class<? extends NodeConfiguration> configClazz();
 
+    ComponentSingletonSupport singleton() default ComponentSingletonSupport.NOT_SUPPORTED;
+
     boolean inEnabled() default true;
 
     boolean outEnabled() default true;
diff --git a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/TbMqttNode.java b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/TbMqttNode.java
index d1feae6271..95ba04d687 100644
--- a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/TbMqttNode.java
+++ b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/TbMqttNode.java
@@ -33,6 +33,7 @@ import org.thingsboard.rule.engine.api.util.TbNodeUtils;
 import org.thingsboard.rule.engine.credentials.BasicCredentials;
 import org.thingsboard.rule.engine.credentials.ClientCredentials;
 import org.thingsboard.rule.engine.credentials.CredentialsType;
+import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
 import org.thingsboard.server.common.data.plugin.ComponentType;
 import org.thingsboard.server.common.msg.TbMsg;
 import org.thingsboard.server.common.msg.TbMsgMetaData;
@@ -47,6 +48,7 @@ import java.util.concurrent.TimeoutException;
         type = ComponentType.EXTERNAL,
         name = "mqtt",
         configClazz = TbMqttNodeConfiguration.class,
+        singleton = ComponentSingletonSupport.SUPPORTED,
         nodeDescription = "Publish messages to the MQTT broker",
         nodeDetails = "Will publish message payload to the MQTT broker with QoS <b>AT_LEAST_ONCE</b>.",
         uiResources = {"static/rulenode/rulenode-core-config.js"},
diff --git a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/azure/TbAzureIotHubNode.java b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/azure/TbAzureIotHubNode.java
index 34c26d820d..0b3d8f36ad 100644
--- a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/azure/TbAzureIotHubNode.java
+++ b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/azure/TbAzureIotHubNode.java
@@ -16,9 +16,7 @@
 package org.thingsboard.rule.engine.mqtt.azure;
 
 import io.netty.handler.codec.mqtt.MqttVersion;
-import io.netty.handler.ssl.SslContext;
 import lombok.extern.slf4j.Slf4j;
-import org.thingsboard.server.common.data.StringUtils;
 import org.thingsboard.common.util.AzureIotHubUtil;
 import org.thingsboard.mqtt.MqttClientConfig;
 import org.thingsboard.rule.engine.api.RuleNode;
@@ -26,12 +24,12 @@ import org.thingsboard.rule.engine.api.TbContext;
 import org.thingsboard.rule.engine.api.TbNodeConfiguration;
 import org.thingsboard.rule.engine.api.TbNodeException;
 import org.thingsboard.rule.engine.api.util.TbNodeUtils;
-import org.thingsboard.rule.engine.credentials.BasicCredentials;
 import org.thingsboard.rule.engine.credentials.CertPemCredentials;
 import org.thingsboard.rule.engine.credentials.ClientCredentials;
 import org.thingsboard.rule.engine.credentials.CredentialsType;
 import org.thingsboard.rule.engine.mqtt.TbMqttNode;
 import org.thingsboard.rule.engine.mqtt.TbMqttNodeConfiguration;
+import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
 import org.thingsboard.server.common.data.plugin.ComponentType;
 
 import javax.net.ssl.SSLException;
@@ -41,6 +39,7 @@ import javax.net.ssl.SSLException;
         type = ComponentType.EXTERNAL,
         name = "azure iot hub",
         configClazz = TbAzureIotHubNodeConfiguration.class,
+        singleton = ComponentSingletonSupport.ONLY_SINGLETON,
         nodeDescription = "Publish messages to the Azure IoT Hub",
         nodeDetails = "Will publish message payload to the Azure IoT Hub with QoS <b>AT_LEAST_ONCE</b>.",
         uiResources = {"static/rulenode/rulenode-core-config.js"},
diff --git a/ui-ngx/src/app/modules/home/components/import-export/import-export.service.ts b/ui-ngx/src/app/modules/home/components/import-export/import-export.service.ts
index a4b3a1d4de..a6e7e7f89e 100644
--- a/ui-ngx/src/app/modules/home/components/import-export/import-export.service.ts
+++ b/ui-ngx/src/app/modules/home/components/import-export/import-export.service.ts
@@ -467,6 +467,7 @@ export class ImportExportService {
           const ruleChainNode: RuleNode = {
             name: '',
             debugMode: false,
+            singletonMode: false,
             type: 'org.thingsboard.rule.engine.flow.TbRuleChainInputNode',
             configuration: {
               ruleChainId: ruleChainConnection.targetRuleChainId.id
diff --git a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.html b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.html
index b6912f0b00..4a237663b9 100644
--- a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.html
+++ b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.html
@@ -39,6 +39,9 @@
         <mat-checkbox formControlName="debugMode">
           {{ 'rulenode.debug-mode' | translate }}
         </mat-checkbox>
+        <mat-checkbox *ngIf="isSingletonEditAllowed()" formControlName="singletonMode">
+          {{ 'rulenode.singleton-mode' | translate }}
+        </mat-checkbox>
       </section>
       <tb-rule-node-config #ruleNodeConfigComponent
         formControlName="configuration"
diff --git a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts
index a0df64cd0e..dd21990c1e 100644
--- a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts
+++ b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts
@@ -26,6 +26,7 @@ import { RuleChainService } from '@core/http/rule-chain.service';
 import { RuleNodeConfigComponent } from './rule-node-config.component';
 import { Router } from '@angular/router';
 import { RuleChainType } from '@app/shared/models/rule-chain.models';
+import { ComponentSingletonSupport } from "@shared/models/component-descriptor.models";
 
 @Component({
   selector: 'tb-rule-node',
@@ -78,6 +79,7 @@ export class RuleNodeDetailsComponent extends PageComponent implements OnInit, O
       this.ruleNodeFormGroup = this.fb.group({
         name: [this.ruleNode.name, [Validators.required, Validators.pattern('(.|\\s)*\\S(.|\\s)*'), Validators.maxLength(255)]],
         debugMode: [this.ruleNode.debugMode, []],
+        singletonMode: [this.ruleNode.singletonMode, []],
         configuration: [this.ruleNode.configuration, [Validators.required]],
         additionalInfo: this.fb.group(
           {
@@ -130,4 +132,8 @@ export class RuleNodeDetailsComponent extends PageComponent implements OnInit, O
       }
     }
   }
+
+  isSingletonEditAllowed() {
+    return this.ruleNode.component.singleton === ComponentSingletonSupport.SUPPORTED;
+  }
 }
diff --git a/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts b/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts
index ab553793fc..72dd1415ee 100644
--- a/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts
+++ b/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts
@@ -554,6 +554,7 @@ export class RuleChainPageComponent extends PageComponent
         additionalInfo: ruleNode.additionalInfo,
         configuration: ruleNode.configuration,
         debugMode: ruleNode.debugMode,
+        singletonMode: ruleNode.singletonMode,
         x: Math.round(ruleNode.additionalInfo.layoutX),
         y: Math.round(ruleNode.additionalInfo.layoutY),
         component,
@@ -912,7 +913,8 @@ export class RuleChainPageComponent extends PageComponent
             name: node.name,
             configuration: deepClone(node.configuration),
             additionalInfo: node.additionalInfo ? deepClone(node.additionalInfo) : {},
-            debugMode: node.debugMode
+            debugMode: node.debugMode,
+            singletonMode: node.singletonMode
           };
           if (minX === null) {
             minX = node.x;
@@ -983,7 +985,8 @@ export class RuleChainPageComponent extends PageComponent
             name: outputEdge.label,
             configuration: {},
             additionalInfo: {},
-            debugMode: false
+            debugMode: false,
+            singletonMode: false
           };
           outputNode.additionalInfo.layoutX = Math.round(destNode.x);
           outputNode.additionalInfo.layoutY = Math.round(destNode.y);
@@ -1029,6 +1032,7 @@ export class RuleChainPageComponent extends PageComponent
               ruleChainId: ruleChain.id.id
             },
             debugMode: false,
+            singletonMode: false,
             x: Math.round(ruleChainNodeX),
             y: Math.round(ruleChainNodeY),
             nodeClass: descriptor.nodeClass,
@@ -1420,7 +1424,8 @@ export class RuleChainPageComponent extends PageComponent
             name: node.name,
             configuration: node.configuration,
             additionalInfo: node.additionalInfo ? node.additionalInfo : {},
-            debugMode: node.debugMode
+            debugMode: node.debugMode,
+            singletonMode: node.singletonMode
           };
           ruleNode.additionalInfo.layoutX = Math.round(node.x);
           ruleNode.additionalInfo.layoutY = Math.round(node.y);
diff --git a/ui-ngx/src/app/shared/models/component-descriptor.models.ts b/ui-ngx/src/app/shared/models/component-descriptor.models.ts
index 56dd29cb4e..d8e4aba2aa 100644
--- a/ui-ngx/src/app/shared/models/component-descriptor.models.ts
+++ b/ui-ngx/src/app/shared/models/component-descriptor.models.ts
@@ -30,9 +30,16 @@ export enum ComponentScope {
   TENANT = 'TENANT'
 }
 
+export enum ComponentSingletonSupport {
+  SUPPORTED = 'SUPPORTED',
+  NOT_SUPPORTED = 'NOT_SUPPORTED',
+  ONLY_SINGLETON = 'ONLY_SINGLETON'
+}
+
 export interface ComponentDescriptor {
   type: ComponentType | RuleNodeType;
   scope?: ComponentScope;
+  singleton: ComponentSingletonSupport;
   name: string;
   clazz: string;
   configurationDescriptor?: any;
diff --git a/ui-ngx/src/app/shared/models/rule-chain.models.ts b/ui-ngx/src/app/shared/models/rule-chain.models.ts
index 20086ca21b..57a58ba110 100644
--- a/ui-ngx/src/app/shared/models/rule-chain.models.ts
+++ b/ui-ngx/src/app/shared/models/rule-chain.models.ts
@@ -19,7 +19,7 @@ import { TenantId } from '@shared/models/id/tenant-id';
 import { RuleChainId } from '@shared/models/id/rule-chain-id';
 import { RuleNodeId } from '@shared/models/id/rule-node-id';
 import { RuleNode, RuleNodeComponentDescriptor, RuleNodeType } from '@shared/models/rule-node.models';
-import { ComponentType } from '@shared/models/component-descriptor.models';
+import { ComponentSingletonSupport, ComponentType } from '@shared/models/component-descriptor.models';
 
 export interface RuleChain extends BaseData<RuleChainId>, ExportableEntity<RuleChainId> {
   tenantId: TenantId;
@@ -64,6 +64,7 @@ export const ruleNodeTypeComponentTypes: ComponentType[] =
 export const unknownNodeComponent: RuleNodeComponentDescriptor = {
   type: RuleNodeType.UNKNOWN,
   name: 'unknown',
+  singleton: ComponentSingletonSupport.NOT_SUPPORTED,
   clazz: 'tb.internal.Unknown',
   configurationDescriptor: {
     nodeDefinition: {
@@ -80,6 +81,7 @@ export const unknownNodeComponent: RuleNodeComponentDescriptor = {
 
 export const inputNodeComponent: RuleNodeComponentDescriptor = {
   type: RuleNodeType.INPUT,
+  singleton: ComponentSingletonSupport.NOT_SUPPORTED,
   name: 'Input',
   clazz: 'tb.internal.Input'
 };
diff --git a/ui-ngx/src/app/shared/models/rule-node.models.ts b/ui-ngx/src/app/shared/models/rule-node.models.ts
index 9d78a5ced8..8ad24b795b 100644
--- a/ui-ngx/src/app/shared/models/rule-node.models.ts
+++ b/ui-ngx/src/app/shared/models/rule-node.models.ts
@@ -36,6 +36,7 @@ export interface RuleNode extends BaseData<RuleNodeId> {
   type: string;
   name: string;
   debugMode: boolean;
+  singletonMode: boolean;
   configuration: RuleNodeConfiguration;
   additionalInfo?: any;
 }
@@ -318,6 +319,7 @@ export interface FcRuleNode extends FcRuleNodeType {
   additionalInfo?: any;
   configuration?: RuleNodeConfiguration;
   debugMode?: boolean;
+  singletonMode?: boolean;
   error?: string;
   highlighted?: boolean;
   componentClazz?: string;
diff --git a/ui-ngx/src/assets/locale/locale.constant-en_US.json b/ui-ngx/src/assets/locale/locale.constant-en_US.json
index 8c664e48f5..73687635db 100644
--- a/ui-ngx/src/assets/locale/locale.constant-en_US.json
+++ b/ui-ngx/src/assets/locale/locale.constant-en_US.json
@@ -3304,6 +3304,7 @@
         "deselect-all": "Deselect all",
         "rulenode-details": "Rule node details",
         "debug-mode": "Debug mode",
+        "singleton-mode": "Singleton mode",
         "configuration": "Configuration",
         "link": "Link",
         "link-details": "Rule node link details",

From 527e39caaf25b3e6d717610a027d508251c17865 Mon Sep 17 00:00:00 2001
From: YevhenBondarenko <ybondarenko@thingsboard.io>
Date: Fri, 21 Apr 2023 09:57:41 +0200
Subject: [PATCH 03/11] minor improvements

---
 .../actors/ruleChain/RuleNodeActorMessageProcessor.java      | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
index 223dfa2de2..1694008da6 100644
--- a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
+++ b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
@@ -89,7 +89,7 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
             }
         } else {
             if (tbNode != null) {
-                tbNode.destroy();
+                stop(null);
                 tbNode = null;
             }
         }
@@ -107,7 +107,7 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     public void onPartitionChangeMsg(PartitionChangeMsg msg) throws Exception {
         if (tbNode != null) {
             if (!isMyNode()) {
-                tbNode.destroy();
+                stop(null);
                 tbNode = null;
             } else {
                 tbNode.onPartitionChangeMsg(defaultCtx, msg);
@@ -185,7 +185,6 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     private boolean isMyNode() {
         return systemContext.getDiscoveryService().isMonolith()
                 || !ruleNode.isSingletonMode()
-//                || !ruleNode.getName().equals("singleton")
                 || defaultCtx.isLocalEntity(ruleNode.getId());
     }
 

From c3fd37553683ea8c86ac6fdc9814619831565fb5 Mon Sep 17 00:00:00 2001
From: YevhenBondarenko <ybondarenko@thingsboard.io>
Date: Fri, 21 Apr 2023 10:32:56 +0200
Subject: [PATCH 04/11] Component desctiptor repository improvements

---
 .../AbstractComponentDescriptorInsertRepository.java          | 3 ++-
 .../sql/component/SqlComponentDescriptorInsertRepository.java | 4 ++--
 dao/src/main/resources/sql/schema-entities.sql                | 4 +++-
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/dao/src/main/java/org/thingsboard/server/dao/sql/component/AbstractComponentDescriptorInsertRepository.java b/dao/src/main/java/org/thingsboard/server/dao/sql/component/AbstractComponentDescriptorInsertRepository.java
index f64ac48c53..4aba74d2cb 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/sql/component/AbstractComponentDescriptorInsertRepository.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/sql/component/AbstractComponentDescriptorInsertRepository.java
@@ -76,7 +76,8 @@ public abstract class AbstractComponentDescriptorInsertRepository implements Com
                 .setParameter("name", entity.getName())
                 .setParameter("scope", entity.getScope().name())
                 .setParameter("search_text", entity.getSearchText())
-                .setParameter("type", entity.getType().name());
+                .setParameter("type", entity.getType().name())
+                .setParameter("singleton", entity.getSingleton().name());
     }
 
     private ComponentDescriptorEntity processSaveOrUpdate(ComponentDescriptorEntity entity, String query) {
diff --git a/dao/src/main/java/org/thingsboard/server/dao/sql/component/SqlComponentDescriptorInsertRepository.java b/dao/src/main/java/org/thingsboard/server/dao/sql/component/SqlComponentDescriptorInsertRepository.java
index 98eb76da87..0db38f2c71 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/sql/component/SqlComponentDescriptorInsertRepository.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/sql/component/SqlComponentDescriptorInsertRepository.java
@@ -44,10 +44,10 @@ public class SqlComponentDescriptorInsertRepository extends AbstractComponentDes
     }
 
     private static String getInsertOrUpdateStatement(String conflictKeyStatement, String updateKeyStatement) {
-        return "INSERT INTO component_descriptor (id, created_time, actions, clazz, configuration_descriptor, name, scope, search_text, type) VALUES (:id, :created_time, :actions, :clazz, :configuration_descriptor, :name, :scope, :search_text, :type) ON CONFLICT " + conflictKeyStatement + " DO UPDATE SET " + updateKeyStatement + " returning *";
+        return "INSERT INTO component_descriptor (id, created_time, actions, clazz, configuration_descriptor, name, scope, search_text, type, singleton) VALUES (:id, :created_time, :actions, :clazz, :configuration_descriptor, :name, :scope, :search_text, :type, :singleton) ON CONFLICT " + conflictKeyStatement + " DO UPDATE SET " + updateKeyStatement + " returning *";
     }
 
     private static String getUpdateStatement(String id) {
-        return "actions = :actions, " + id + ",created_time = :created_time, configuration_descriptor = :configuration_descriptor, name = :name, scope = :scope, search_text = :search_text, type = :type";
+        return "actions = :actions, " + id + ",created_time = :created_time, configuration_descriptor = :configuration_descriptor, name = :name, scope = :scope, search_text = :search_text, type = :type, singleton = :singleton";
     }
 }
diff --git a/dao/src/main/resources/sql/schema-entities.sql b/dao/src/main/resources/sql/schema-entities.sql
index ddd60ae812..2fdc8e4ce0 100644
--- a/dao/src/main/resources/sql/schema-entities.sql
+++ b/dao/src/main/resources/sql/schema-entities.sql
@@ -125,7 +125,8 @@ CREATE TABLE IF NOT EXISTS component_descriptor (
     name varchar(255),
     scope varchar(255),
     search_text varchar(255),
-    type varchar(255)
+    type varchar(255),
+    singleton varchar(255)
 );
 
 CREATE TABLE IF NOT EXISTS customer (
@@ -187,6 +188,7 @@ CREATE TABLE IF NOT EXISTS rule_node (
     type varchar(255),
     name varchar(255),
     debug_mode boolean,
+    singleton_mode boolean,
     search_text varchar(255),
     external_id uuid
 );

From ed1b5a0af7be350a69603f4fbdae3547afdf7523 Mon Sep 17 00:00:00 2001
From: Vladyslav_Prykhodko <vprykhodko@thingsboard.io>
Date: Fri, 21 Apr 2023 13:57:05 +0300
Subject: [PATCH 05/11] UI: Refactoring singletonMode in rule chain nodes

---
 .../rule-node-details.component.html          | 16 ++++++++------
 .../rule-node-details.component.scss          | 22 +++++++++++++++++++
 .../rulechain/rule-node-details.component.ts  |  2 +-
 .../rulechain/rulechain-page.component.ts     |  2 ++
 .../src/app/shared/models/rule-node.models.ts |  2 +-
 5 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.html b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.html
index 4a237663b9..35a564182c 100644
--- a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.html
+++ b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.html
@@ -24,7 +24,7 @@
 <form [formGroup]="ruleNodeFormGroup" class="mat-padding">
   <fieldset [disabled]="(isLoading$ | async) || !isEdit || isReadOnly">
     <section>
-      <section fxLayout="column" fxLayout.gt-sm="row">
+      <section class="title-row">
         <mat-form-field fxFlex class="mat-block">
           <mat-label translate>rulenode.name</mat-label>
           <input matInput formControlName="name" required>
@@ -36,12 +36,14 @@
             {{ 'rulenode.name-max-length' | translate }}
           </mat-error>
         </mat-form-field>
-        <mat-checkbox formControlName="debugMode">
-          {{ 'rulenode.debug-mode' | translate }}
-        </mat-checkbox>
-        <mat-checkbox *ngIf="isSingletonEditAllowed()" formControlName="singletonMode">
-          {{ 'rulenode.singleton-mode' | translate }}
-        </mat-checkbox>
+        <section class="node-setting">
+          <mat-slide-toggle formControlName="debugMode">
+            {{ 'rulenode.debug-mode' | translate }}
+          </mat-slide-toggle>
+          <mat-slide-toggle *ngIf="isSingletonEditAllowed()" formControlName="singletonMode">
+            {{ 'rulenode.singleton-mode' | translate }}
+          </mat-slide-toggle >
+        </section>
       </section>
       <tb-rule-node-config #ruleNodeConfigComponent
         formControlName="configuration"
diff --git a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.scss b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.scss
index 4dce88573d..4995d5c06d 100644
--- a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.scss
+++ b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.scss
@@ -13,8 +13,30 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+@import './../scss/constants';
+
 :host {
   form {
     overflow-x: hidden !important;
   }
+  .title-row {
+    display: flex;
+    flex-direction: column;
+
+    .node-setting {
+      display: flex;
+      flex-direction: column;
+      gap: 8px;
+      margin-bottom: 5px;
+    }
+
+    @media #{$mat-gt-sm} {
+      flex-direction: row;
+      gap: 8px;
+
+      .node-setting {
+        margin-top: 5px;
+      }
+    }
+  }
 }
diff --git a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts
index dd21990c1e..320ece312b 100644
--- a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts
+++ b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts
@@ -26,7 +26,7 @@ import { RuleChainService } from '@core/http/rule-chain.service';
 import { RuleNodeConfigComponent } from './rule-node-config.component';
 import { Router } from '@angular/router';
 import { RuleChainType } from '@app/shared/models/rule-chain.models';
-import { ComponentSingletonSupport } from "@shared/models/component-descriptor.models";
+import { ComponentSingletonSupport } from '@shared/models/component-descriptor.models';
 
 @Component({
   selector: 'tb-rule-node',
diff --git a/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts b/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts
index 72dd1415ee..9e68306ac4 100644
--- a/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts
+++ b/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts
@@ -89,6 +89,7 @@ import { DebugEventType, EventType } from '@shared/models/event.models';
 import { MatMiniFabButton } from '@angular/material/button';
 import { TbPopoverService } from '@shared/components/popover.service';
 import { VersionControlComponent } from '@home/components/vc/version-control.component';
+import { ComponentSingletonSupport } from '@shared/models/component-descriptor.models';
 import Timeout = NodeJS.Timeout;
 
 @Component({
@@ -469,6 +470,7 @@ export class RuleChainPageComponent extends PageComponent
         component: ruleNodeComponent,
         name: '',
         nodeClass: desc.nodeClass,
+        singletonMode: ruleNodeComponent.singleton !== ComponentSingletonSupport.NOT_SUPPORTED,
         icon,
         iconUrl,
         x: 30,
diff --git a/ui-ngx/src/app/shared/models/rule-node.models.ts b/ui-ngx/src/app/shared/models/rule-node.models.ts
index 8ad24b795b..54ab4bc126 100644
--- a/ui-ngx/src/app/shared/models/rule-node.models.ts
+++ b/ui-ngx/src/app/shared/models/rule-node.models.ts
@@ -309,6 +309,7 @@ export interface RuleNodeComponentDescriptor extends ComponentDescriptor {
 
 export interface FcRuleNodeType extends FcNode {
   component?: RuleNodeComponentDescriptor;
+  singletonMode?: boolean;
   nodeClass?: string;
   icon?: string;
   iconUrl?: string;
@@ -319,7 +320,6 @@ export interface FcRuleNode extends FcRuleNodeType {
   additionalInfo?: any;
   configuration?: RuleNodeConfiguration;
   debugMode?: boolean;
-  singletonMode?: boolean;
   error?: string;
   highlighted?: boolean;
   componentClazz?: string;

From e342ce1b3eef831adc977b2068eb9ca22bf61890 Mon Sep 17 00:00:00 2001
From: YevhenBondarenko <ybondarenko@thingsboard.io>
Date: Fri, 21 Apr 2023 14:01:35 +0200
Subject: [PATCH 06/11] refactoring

---
 .../server/actors/ruleChain/RuleChainActorMessageProcessor.java  | 1 -
 1 file changed, 1 deletion(-)

diff --git a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleChainActorMessageProcessor.java b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleChainActorMessageProcessor.java
index 12ea2fd651..0e1e25bd27 100644
--- a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleChainActorMessageProcessor.java
+++ b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleChainActorMessageProcessor.java
@@ -388,7 +388,6 @@ public class RuleChainActorMessageProcessor extends ComponentMsgProcessor<RuleCh
 
     private void pushMsgToNode(RuleNodeCtx nodeCtx, TbMsg msg, String fromRelationType) {
         if (nodeCtx != null) {
-            //TODO: analyze that singleton flag and execute putToQueue if needed.
             nodeCtx.getSelfActor().tell(new RuleChainToRuleNodeMsg(new DefaultTbContext(systemContext, ruleChainName, nodeCtx), msg, fromRelationType));
         } else {
             log.error("[{}][{}] RuleNodeCtx is empty", entityId, ruleChainName);

From 8d2f6eb8562f7a17d518f55c84cd7e5c472a32a2 Mon Sep 17 00:00:00 2001
From: YevhenBondarenko <ybondarenko@thingsboard.io>
Date: Fri, 21 Apr 2023 18:30:47 +0200
Subject: [PATCH 07/11] Added singleton mode validation and tests

---
 .../RuleNodeActorMessageProcessor.java        |  4 +-
 .../service/RuleChainDataValidatorTest.java   | 66 +++++++++++++++++++
 .../validator/RuleChainDataValidator.java     | 21 +++++-
 3 files changed, 86 insertions(+), 5 deletions(-)
 create mode 100644 application/src/test/java/org/thingsboard/server/service/RuleChainDataValidatorTest.java

diff --git a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
index 1694008da6..3e6853287c 100644
--- a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
+++ b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
@@ -183,8 +183,8 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     }
 
     private boolean isMyNode() {
-        return systemContext.getDiscoveryService().isMonolith()
-                || !ruleNode.isSingletonMode()
+        return !ruleNode.isSingletonMode()
+                || systemContext.getDiscoveryService().isMonolith()
                 || defaultCtx.isLocalEntity(ruleNode.getId());
     }
 
diff --git a/application/src/test/java/org/thingsboard/server/service/RuleChainDataValidatorTest.java b/application/src/test/java/org/thingsboard/server/service/RuleChainDataValidatorTest.java
new file mode 100644
index 0000000000..cc31a9f6ff
--- /dev/null
+++ b/application/src/test/java/org/thingsboard/server/service/RuleChainDataValidatorTest.java
@@ -0,0 +1,66 @@
+/**
+ * Copyright © 2016-2023 The Thingsboard Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.thingsboard.server.service;
+
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+import org.thingsboard.common.util.JacksonUtil;
+import org.thingsboard.server.common.data.rule.RuleNode;
+import org.thingsboard.server.dao.exception.DataValidationException;
+import org.thingsboard.server.dao.service.validator.RuleChainDataValidator;
+
+public class RuleChainDataValidatorTest {
+
+    @Test
+    public void testSingletonSupport() {
+        String node = "org.thingsboard.rule.engine.mqtt.TbMqttNode";
+        RuleNode ruleNode = createRuleNode(node, false);
+        RuleChainDataValidator.validateRuleNode(ruleNode);
+        ruleNode.setSingletonMode(true);
+        RuleChainDataValidator.validateRuleNode(ruleNode);
+    }
+
+    @Test
+    public void testSingletonNotSupport() {
+        String node = "org.thingsboard.rule.engine.flow.TbAckNode";
+        RuleNode ruleNode = createRuleNode(node, false);
+        RuleChainDataValidator.validateRuleNode(ruleNode);
+        ruleNode.setSingletonMode(true);
+        Assertions.assertThrows(DataValidationException.class,
+                () -> RuleChainDataValidator.validateRuleNode(ruleNode),
+                String.format("Singleton mode not supported for [%s].", ruleNode.getType()));
+    }
+
+    @Test
+    public void testSingletonOnly() {
+        String node = "org.thingsboard.rule.engine.mqtt.azure.TbAzureIotHubNode";
+        RuleNode ruleNode = createRuleNode(node, true);
+        RuleChainDataValidator.validateRuleNode(ruleNode);
+        ruleNode.setSingletonMode(false);
+        Assertions.assertThrows(DataValidationException.class,
+                () -> RuleChainDataValidator.validateRuleNode(ruleNode),
+                String.format("Supported only singleton mode for [%s].", ruleNode.getType()));
+    }
+
+    private RuleNode createRuleNode(String type, boolean singletonMode) {
+        RuleNode ruleNode = new RuleNode();
+        ruleNode.setName("test node");
+        ruleNode.setType(type);
+        ruleNode.setSingletonMode(singletonMode);
+        ruleNode.setConfiguration(JacksonUtil.newObjectNode());
+        return ruleNode;
+    }
+}
diff --git a/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java b/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java
index ac145034a5..0e22ae2b93 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java
@@ -25,19 +25,18 @@ import org.thingsboard.common.util.JacksonUtil;
 import org.thingsboard.server.common.data.EntityType;
 import org.thingsboard.server.common.data.StringUtils;
 import org.thingsboard.server.common.data.id.TenantId;
+import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
 import org.thingsboard.server.common.data.rule.NodeConnectionInfo;
 import org.thingsboard.server.common.data.rule.RuleChain;
 import org.thingsboard.server.common.data.rule.RuleChainMetaData;
 import org.thingsboard.server.common.data.rule.RuleChainType;
 import org.thingsboard.server.common.data.rule.RuleNode;
-import org.thingsboard.server.common.data.tenant.profile.DefaultTenantProfileConfiguration;
 import org.thingsboard.server.common.data.util.ReflectionUtils;
 import org.thingsboard.server.dao.exception.DataValidationException;
 import org.thingsboard.server.dao.rule.RuleChainDao;
 import org.thingsboard.server.dao.rule.RuleChainService;
 import org.thingsboard.server.dao.service.ConstraintValidator;
 import org.thingsboard.server.dao.service.DataValidator;
-import org.thingsboard.server.dao.tenant.TbTenantProfileCache;
 import org.thingsboard.server.dao.tenant.TenantService;
 
 import java.util.HashMap;
@@ -62,7 +61,7 @@ public class RuleChainDataValidator extends DataValidator<RuleChain> {
 
     @Override
     protected void validateCreate(TenantId tenantId, RuleChain data) {
-         validateNumberOfEntitiesPerTenant(tenantId, EntityType.RULE_CHAIN);
+        validateNumberOfEntitiesPerTenant(tenantId, EntityType.RULE_CHAIN);
     }
 
     @Override
@@ -114,6 +113,22 @@ public class RuleChainDataValidator extends DataValidator<RuleChain> {
             return;
         }
         ConstraintValidator.validateFields(nodeConfig, errorPrefix);
+
+        ComponentSingletonSupport nodeConfigType = null;
+        try {
+            nodeConfigType = ReflectionUtils.getAnnotationProperty(ruleNode.getType(),
+                    "org.thingsboard.rule.engine.api.RuleNode", "singleton");
+        } catch (Exception e) {
+            log.warn("Failed to validate singleton mode: {}", ExceptionUtils.getRootCauseMessage(e));
+            return;
+        }
+        if (ComponentSingletonSupport.NOT_SUPPORTED.equals(nodeConfigType) && ruleNode.isSingletonMode()) {
+            throw new DataValidationException(String.format("Singleton mode not supported for [%s].", ruleNode.getType()));
+        }
+
+        if (ComponentSingletonSupport.ONLY_SINGLETON.equals(nodeConfigType) && !ruleNode.isSingletonMode()) {
+            throw new DataValidationException(String.format("Supported only singleton mode for [%s].", ruleNode.getType()));
+        }
     }
 
     private static void validateCircles(List<NodeConnectionInfo> connectionInfos) {

From da0bd1dc923163d010a3a841c68498c5ed598888 Mon Sep 17 00:00:00 2001
From: YevhenBondarenko <ybondarenko@thingsboard.io>
Date: Mon, 24 Apr 2023 13:49:57 +0200
Subject: [PATCH 08/11] renamed SingletonSupport to ClusteringMode and
 refactoring due to comments

---
 .../main/data/upgrade/3.4.4/schema_update.sql |  6 +++---
 .../RuleNodeActorMessageProcessor.java        | 20 +++++++++----------
 .../AnnotationComponentDiscoveryService.java  |  2 +-
 ...port.java => ComponentClusteringMode.java} |  8 ++++----
 .../data/plugin/ComponentDescriptor.java      | 12 +++++------
 .../server/dao/model/ModelConstants.java      |  2 +-
 .../model/sql/ComponentDescriptorEntity.java  | 10 +++++-----
 .../validator/RuleChainDataValidator.java     | 10 +++++-----
 ...ctComponentDescriptorInsertRepository.java |  2 +-
 ...qlComponentDescriptorInsertRepository.java |  4 ++--
 .../main/resources/sql/schema-entities.sql    |  2 +-
 .../thingsboard/rule/engine/api/RuleNode.java |  4 ++--
 .../rule/engine/mqtt/TbMqttNode.java          |  4 ++--
 .../engine/mqtt/azure/TbAzureIotHubNode.java  |  4 ++--
 .../rulechain/rule-node-details.component.ts  |  4 ++--
 .../rulechain/rulechain-page.component.ts     |  4 ++--
 .../models/component-descriptor.models.ts     | 10 +++++-----
 .../app/shared/models/rule-chain.models.ts    |  6 +++---
 18 files changed, 56 insertions(+), 58 deletions(-)
 rename common/data/src/main/java/org/thingsboard/server/common/data/plugin/{ComponentSingletonSupport.java => ComponentClusteringMode.java} (87%)

diff --git a/application/src/main/data/upgrade/3.4.4/schema_update.sql b/application/src/main/data/upgrade/3.4.4/schema_update.sql
index e15a9fb9e9..0dc54a134f 100644
--- a/application/src/main/data/upgrade/3.4.4/schema_update.sql
+++ b/application/src/main/data/upgrade/3.4.4/schema_update.sql
@@ -617,9 +617,9 @@ ALTER TABLE rule_node ADD COLUMN IF NOT EXISTS singleton_mode bool DEFAULT false
 
 UPDATE rule_node SET singleton_mode = true WHERE type IN ('org.thingsboard.rule.engine.mqtt.azure.TbAzureIotHubNode', 'org.thingsboard.rule.engine.mqtt.TbMqttNode');
 
-ALTER TABLE component_descriptor ADD COLUMN IF NOT EXISTS singleton varchar(255) DEFAULT 'NOT_SUPPORTED';
+ALTER TABLE component_descriptor ADD COLUMN IF NOT EXISTS clustering_mode varchar(255) DEFAULT 'ENABLED';
 
-UPDATE component_descriptor SET singleton = 'SUPPORTED' WHERE name = 'mqtt';
+UPDATE component_descriptor SET clustering_mode = 'USER_PREFERENCE' WHERE clazz = 'org.thingsboard.rule.engine.mqtt.TbMqttNode';
 
-UPDATE component_descriptor SET singleton = 'ONLY_SINGLETON' WHERE name = 'azure iot hub';
+UPDATE component_descriptor SET clustering_mode = 'SINGLETON' WHERE clazz = 'org.thingsboard.rule.engine.mqtt.azure.TbAzureIotHubNode';
 
diff --git a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
index 3e6853287c..37964a8005 100644
--- a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
+++ b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
@@ -60,7 +60,7 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
 
     @Override
     public void start(TbActorCtx context) throws Exception {
-        if (isMyNode()) {
+        if (isMySingletonNode()) {
             tbNode = initComponent(ruleNode);
             if (tbNode != null) {
                 state = ComponentLifecycleState.ACTIVE;
@@ -70,7 +70,7 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
 
     @Override
     public void onUpdate(TbActorCtx context) throws Exception {
-        if (isMyNode()) {
+        if (isMySingletonNode()) {
             RuleNode newRuleNode = systemContext.getRuleChainService().findRuleNodeById(tenantId, entityId);
             this.info = new RuleNodeInfo(entityId, ruleChainName, newRuleNode != null ? newRuleNode.getName() : "Unknown");
             boolean restartRequired = state != ComponentLifecycleState.ACTIVE ||
@@ -87,11 +87,9 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
                     throw new TbRuleNodeUpdateException("Failed to update rule node", e);
                 }
             }
-        } else {
-            if (tbNode != null) {
-                stop(null);
-                tbNode = null;
-            }
+        } else if (tbNode != null) {
+            stop(null);
+            tbNode = null;
         }
     }
 
@@ -106,13 +104,13 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     @Override
     public void onPartitionChangeMsg(PartitionChangeMsg msg) throws Exception {
         if (tbNode != null) {
-            if (!isMyNode()) {
+            if (!isMySingletonNode()) {
                 stop(null);
                 tbNode = null;
             } else {
                 tbNode.onPartitionChangeMsg(defaultCtx, msg);
             }
-        } else if (isMyNode()) {
+        } else if (isMySingletonNode()) {
             start(null);
         }
     }
@@ -138,7 +136,7 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     }
 
     void onRuleChainToRuleNodeMsg(RuleChainToRuleNodeMsg msg) throws Exception {
-        if (!isMyNode()) {
+        if (!isMySingletonNode()) {
             putToQueue(msg.getMsg());
         } else {
             msg.getMsg().getCallback().onProcessingStart(info);
@@ -182,7 +180,7 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
         return new RuleNodeException("Rule Node is not active! Failed to initialize.", ruleChainName, ruleNode);
     }
 
-    private boolean isMyNode() {
+    private boolean isMySingletonNode() {
         return !ruleNode.isSingletonMode()
                 || systemContext.getDiscoveryService().isMonolith()
                 || defaultCtx.isLocalEntity(ruleNode.getId());
diff --git a/application/src/main/java/org/thingsboard/server/service/component/AnnotationComponentDiscoveryService.java b/application/src/main/java/org/thingsboard/server/service/component/AnnotationComponentDiscoveryService.java
index bb63f5da4c..b425694e81 100644
--- a/application/src/main/java/org/thingsboard/server/service/component/AnnotationComponentDiscoveryService.java
+++ b/application/src/main/java/org/thingsboard/server/service/component/AnnotationComponentDiscoveryService.java
@@ -155,7 +155,7 @@ public class AnnotationComponentDiscoveryService implements ComponentDiscoverySe
             RuleNode ruleNodeAnnotation = clazz.getAnnotation(RuleNode.class);
             scannedComponent.setName(ruleNodeAnnotation.name());
             scannedComponent.setScope(ruleNodeAnnotation.scope());
-            scannedComponent.setSingleton(ruleNodeAnnotation.singleton());
+            scannedComponent.setClusteringMode(ruleNodeAnnotation.clusteringMode());
             NodeDefinition nodeDefinition = prepareNodeDefinition(ruleNodeAnnotation);
             ObjectNode configurationDescriptor = mapper.createObjectNode();
             JsonNode node = mapper.valueToTree(nodeDefinition);
diff --git a/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentSingletonSupport.java b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentClusteringMode.java
similarity index 87%
rename from common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentSingletonSupport.java
rename to common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentClusteringMode.java
index 0472f26808..32eb43696c 100644
--- a/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentSingletonSupport.java
+++ b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentClusteringMode.java
@@ -15,8 +15,8 @@
  */
 package org.thingsboard.server.common.data.plugin;
 
-public enum ComponentSingletonSupport {
-    SUPPORTED,
-    NOT_SUPPORTED,
-    ONLY_SINGLETON
+public enum ComponentClusteringMode {
+    USER_PREFERENCE,
+    ENABLED,
+    SINGLETON
 }
diff --git a/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentDescriptor.java b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentDescriptor.java
index 9839e34482..bb6235a989 100644
--- a/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentDescriptor.java
+++ b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentDescriptor.java
@@ -36,17 +36,17 @@ public class ComponentDescriptor extends SearchTextBased<ComponentDescriptorId>
     @Getter @Setter private ComponentType type;
     @ApiModelProperty(position = 4, value = "Scope of the Rule Node. Always set to 'TENANT', since no rule chains on the 'SYSTEM' level yet.", accessMode = ApiModelProperty.AccessMode.READ_ONLY, allowableValues = "TENANT", example = "TENANT")
     @Getter @Setter private ComponentScope scope;
-    @ApiModelProperty(position = 4, value = "", accessMode = ApiModelProperty.AccessMode.READ_ONLY, allowableValues = "SUPPORTED, NOT_SUPPORTEd, ONLY_SINGLETON", example = "SUPPORTED")
-    @Getter @Setter private ComponentSingletonSupport singleton;
+    @ApiModelProperty(position = 5, value = "Clustering mode of the RuleNode. This mode represents the ability to start Rule Node in multiple microservices.", accessMode = ApiModelProperty.AccessMode.READ_ONLY, allowableValues = "USER_PREFERENCE, ENABLED, SINGLETON", example = "ENABLED")
+    @Getter @Setter private ComponentClusteringMode clusteringMode;
     @Length(fieldName = "name")
-    @ApiModelProperty(position = 5, value = "Name of the Rule Node. Taken from the @RuleNode annotation.", accessMode = ApiModelProperty.AccessMode.READ_ONLY, example = "Custom Rule Node")
+    @ApiModelProperty(position = 6, value = "Name of the Rule Node. Taken from the @RuleNode annotation.", accessMode = ApiModelProperty.AccessMode.READ_ONLY, example = "Custom Rule Node")
     @Getter @Setter private String name;
-    @ApiModelProperty(position = 6, value = "Full name of the Java class that implements the Rule Engine Node interface.", accessMode = ApiModelProperty.AccessMode.READ_ONLY, example = "com.mycompany.CustomRuleNode")
+    @ApiModelProperty(position = 7, value = "Full name of the Java class that implements the Rule Engine Node interface.", accessMode = ApiModelProperty.AccessMode.READ_ONLY, example = "com.mycompany.CustomRuleNode")
     @Getter @Setter private String clazz;
-    @ApiModelProperty(position = 7, value = "Complex JSON object that represents the Rule Node configuration.", accessMode = ApiModelProperty.AccessMode.READ_ONLY)
+    @ApiModelProperty(position = 8, value = "Complex JSON object that represents the Rule Node configuration.", accessMode = ApiModelProperty.AccessMode.READ_ONLY)
     @Getter @Setter private transient JsonNode configurationDescriptor;
     @Length(fieldName = "actions")
-    @ApiModelProperty(position = 8, value = "Rule Node Actions. Deprecated. Always null.", accessMode = ApiModelProperty.AccessMode.READ_ONLY)
+    @ApiModelProperty(position = 9, value = "Rule Node Actions. Deprecated. Always null.", accessMode = ApiModelProperty.AccessMode.READ_ONLY)
     @Getter @Setter private String actions;
 
     public ComponentDescriptor() {
diff --git a/dao/src/main/java/org/thingsboard/server/dao/model/ModelConstants.java b/dao/src/main/java/org/thingsboard/server/dao/model/ModelConstants.java
index 7b1df3c4a9..bcbed91d2a 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/model/ModelConstants.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/model/ModelConstants.java
@@ -403,7 +403,7 @@ public class ModelConstants {
     public static final String COMPONENT_DESCRIPTOR_COLUMN_FAMILY_NAME = "component_descriptor";
     public static final String COMPONENT_DESCRIPTOR_TYPE_PROPERTY = "type";
     public static final String COMPONENT_DESCRIPTOR_SCOPE_PROPERTY = "scope";
-    public static final String COMPONENT_DESCRIPTOR_SINGLETON_PROPERTY = "singleton";
+    public static final String COMPONENT_DESCRIPTOR_CLUSTERING_MODE_PROPERTY = "clustering_mode";
     public static final String COMPONENT_DESCRIPTOR_NAME_PROPERTY = "name";
     public static final String COMPONENT_DESCRIPTOR_CLASS_PROPERTY = "clazz";
     public static final String COMPONENT_DESCRIPTOR_CONFIGURATION_DESCRIPTOR_PROPERTY = "configuration_descriptor";
diff --git a/dao/src/main/java/org/thingsboard/server/dao/model/sql/ComponentDescriptorEntity.java b/dao/src/main/java/org/thingsboard/server/dao/model/sql/ComponentDescriptorEntity.java
index 47c34e0d58..f22ccffed9 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/model/sql/ComponentDescriptorEntity.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/model/sql/ComponentDescriptorEntity.java
@@ -23,7 +23,7 @@ import org.hibernate.annotations.TypeDef;
 import org.thingsboard.server.common.data.id.ComponentDescriptorId;
 import org.thingsboard.server.common.data.plugin.ComponentDescriptor;
 import org.thingsboard.server.common.data.plugin.ComponentScope;
-import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
+import org.thingsboard.server.common.data.plugin.ComponentClusteringMode;
 import org.thingsboard.server.common.data.plugin.ComponentType;
 import org.thingsboard.server.dao.model.BaseSqlEntity;
 import org.thingsboard.server.dao.model.ModelConstants;
@@ -52,8 +52,8 @@ public class ComponentDescriptorEntity extends BaseSqlEntity<ComponentDescriptor
     private ComponentScope scope;
 
     @Enumerated(EnumType.STRING)
-    @Column(name = ModelConstants.COMPONENT_DESCRIPTOR_SINGLETON_PROPERTY)
-    private ComponentSingletonSupport singleton;
+    @Column(name = ModelConstants.COMPONENT_DESCRIPTOR_CLUSTERING_MODE_PROPERTY)
+    private ComponentClusteringMode clusteringMode;
 
     @Column(name = ModelConstants.COMPONENT_DESCRIPTOR_NAME_PROPERTY)
     private String name;
@@ -82,7 +82,7 @@ public class ComponentDescriptorEntity extends BaseSqlEntity<ComponentDescriptor
         this.actions = component.getActions();
         this.type = component.getType();
         this.scope = component.getScope();
-        this.singleton = component.getSingleton();
+        this.clusteringMode = component.getClusteringMode();
         this.name = component.getName();
         this.clazz = component.getClazz();
         this.configurationDescriptor = component.getConfigurationDescriptor();
@@ -95,7 +95,7 @@ public class ComponentDescriptorEntity extends BaseSqlEntity<ComponentDescriptor
         data.setCreatedTime(createdTime);
         data.setType(type);
         data.setScope(scope);
-        data.setSingleton(singleton);
+        data.setClusteringMode(clusteringMode);
         data.setName(this.getName());
         data.setClazz(this.getClazz());
         data.setActions(this.getActions());
diff --git a/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java b/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java
index 0e22ae2b93..847acf69a2 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java
@@ -25,7 +25,7 @@ import org.thingsboard.common.util.JacksonUtil;
 import org.thingsboard.server.common.data.EntityType;
 import org.thingsboard.server.common.data.StringUtils;
 import org.thingsboard.server.common.data.id.TenantId;
-import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
+import org.thingsboard.server.common.data.plugin.ComponentClusteringMode;
 import org.thingsboard.server.common.data.rule.NodeConnectionInfo;
 import org.thingsboard.server.common.data.rule.RuleChain;
 import org.thingsboard.server.common.data.rule.RuleChainMetaData;
@@ -114,19 +114,19 @@ public class RuleChainDataValidator extends DataValidator<RuleChain> {
         }
         ConstraintValidator.validateFields(nodeConfig, errorPrefix);
 
-        ComponentSingletonSupport nodeConfigType = null;
+        ComponentClusteringMode nodeConfigType = null;
         try {
             nodeConfigType = ReflectionUtils.getAnnotationProperty(ruleNode.getType(),
-                    "org.thingsboard.rule.engine.api.RuleNode", "singleton");
+                    "org.thingsboard.rule.engine.api.RuleNode", "clusteringMode");
         } catch (Exception e) {
             log.warn("Failed to validate singleton mode: {}", ExceptionUtils.getRootCauseMessage(e));
             return;
         }
-        if (ComponentSingletonSupport.NOT_SUPPORTED.equals(nodeConfigType) && ruleNode.isSingletonMode()) {
+        if (ComponentClusteringMode.ENABLED.equals(nodeConfigType) && ruleNode.isSingletonMode()) {
             throw new DataValidationException(String.format("Singleton mode not supported for [%s].", ruleNode.getType()));
         }
 
-        if (ComponentSingletonSupport.ONLY_SINGLETON.equals(nodeConfigType) && !ruleNode.isSingletonMode()) {
+        if (ComponentClusteringMode.SINGLETON.equals(nodeConfigType) && !ruleNode.isSingletonMode()) {
             throw new DataValidationException(String.format("Supported only singleton mode for [%s].", ruleNode.getType()));
         }
     }
diff --git a/dao/src/main/java/org/thingsboard/server/dao/sql/component/AbstractComponentDescriptorInsertRepository.java b/dao/src/main/java/org/thingsboard/server/dao/sql/component/AbstractComponentDescriptorInsertRepository.java
index 4aba74d2cb..943697149c 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/sql/component/AbstractComponentDescriptorInsertRepository.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/sql/component/AbstractComponentDescriptorInsertRepository.java
@@ -77,7 +77,7 @@ public abstract class AbstractComponentDescriptorInsertRepository implements Com
                 .setParameter("scope", entity.getScope().name())
                 .setParameter("search_text", entity.getSearchText())
                 .setParameter("type", entity.getType().name())
-                .setParameter("singleton", entity.getSingleton().name());
+                .setParameter("clustering_mode", entity.getClusteringMode().name());
     }
 
     private ComponentDescriptorEntity processSaveOrUpdate(ComponentDescriptorEntity entity, String query) {
diff --git a/dao/src/main/java/org/thingsboard/server/dao/sql/component/SqlComponentDescriptorInsertRepository.java b/dao/src/main/java/org/thingsboard/server/dao/sql/component/SqlComponentDescriptorInsertRepository.java
index 0db38f2c71..08606f6737 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/sql/component/SqlComponentDescriptorInsertRepository.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/sql/component/SqlComponentDescriptorInsertRepository.java
@@ -44,10 +44,10 @@ public class SqlComponentDescriptorInsertRepository extends AbstractComponentDes
     }
 
     private static String getInsertOrUpdateStatement(String conflictKeyStatement, String updateKeyStatement) {
-        return "INSERT INTO component_descriptor (id, created_time, actions, clazz, configuration_descriptor, name, scope, search_text, type, singleton) VALUES (:id, :created_time, :actions, :clazz, :configuration_descriptor, :name, :scope, :search_text, :type, :singleton) ON CONFLICT " + conflictKeyStatement + " DO UPDATE SET " + updateKeyStatement + " returning *";
+        return "INSERT INTO component_descriptor (id, created_time, actions, clazz, configuration_descriptor, name, scope, search_text, type, clustering_mode) VALUES (:id, :created_time, :actions, :clazz, :configuration_descriptor, :name, :scope, :search_text, :type, :clustering_mode) ON CONFLICT " + conflictKeyStatement + " DO UPDATE SET " + updateKeyStatement + " returning *";
     }
 
     private static String getUpdateStatement(String id) {
-        return "actions = :actions, " + id + ",created_time = :created_time, configuration_descriptor = :configuration_descriptor, name = :name, scope = :scope, search_text = :search_text, type = :type, singleton = :singleton";
+        return "actions = :actions, " + id + ",created_time = :created_time, configuration_descriptor = :configuration_descriptor, name = :name, scope = :scope, search_text = :search_text, type = :type, clustering_mode = :clustering_mode";
     }
 }
diff --git a/dao/src/main/resources/sql/schema-entities.sql b/dao/src/main/resources/sql/schema-entities.sql
index 2fdc8e4ce0..c22feb0695 100644
--- a/dao/src/main/resources/sql/schema-entities.sql
+++ b/dao/src/main/resources/sql/schema-entities.sql
@@ -126,7 +126,7 @@ CREATE TABLE IF NOT EXISTS component_descriptor (
     scope varchar(255),
     search_text varchar(255),
     type varchar(255),
-    singleton varchar(255)
+    clustering_mode varchar(255)
 );
 
 CREATE TABLE IF NOT EXISTS customer (
diff --git a/rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/RuleNode.java b/rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/RuleNode.java
index 9fb8bb66c0..3f7c22576f 100644
--- a/rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/RuleNode.java
+++ b/rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/RuleNode.java
@@ -16,7 +16,7 @@
 package org.thingsboard.rule.engine.api;
 
 import org.thingsboard.server.common.data.plugin.ComponentScope;
-import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
+import org.thingsboard.server.common.data.plugin.ComponentClusteringMode;
 import org.thingsboard.server.common.data.plugin.ComponentType;
 import org.thingsboard.server.common.data.rule.RuleChainType;
 
@@ -39,7 +39,7 @@ public @interface RuleNode {
 
     Class<? extends NodeConfiguration> configClazz();
 
-    ComponentSingletonSupport singleton() default ComponentSingletonSupport.NOT_SUPPORTED;
+    ComponentClusteringMode clusteringMode() default ComponentClusteringMode.ENABLED;
 
     boolean inEnabled() default true;
 
diff --git a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/TbMqttNode.java b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/TbMqttNode.java
index 95ba04d687..86b03cf62e 100644
--- a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/TbMqttNode.java
+++ b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/TbMqttNode.java
@@ -33,7 +33,7 @@ import org.thingsboard.rule.engine.api.util.TbNodeUtils;
 import org.thingsboard.rule.engine.credentials.BasicCredentials;
 import org.thingsboard.rule.engine.credentials.ClientCredentials;
 import org.thingsboard.rule.engine.credentials.CredentialsType;
-import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
+import org.thingsboard.server.common.data.plugin.ComponentClusteringMode;
 import org.thingsboard.server.common.data.plugin.ComponentType;
 import org.thingsboard.server.common.msg.TbMsg;
 import org.thingsboard.server.common.msg.TbMsgMetaData;
@@ -48,7 +48,7 @@ import java.util.concurrent.TimeoutException;
         type = ComponentType.EXTERNAL,
         name = "mqtt",
         configClazz = TbMqttNodeConfiguration.class,
-        singleton = ComponentSingletonSupport.SUPPORTED,
+        clusteringMode = ComponentClusteringMode.USER_PREFERENCE,
         nodeDescription = "Publish messages to the MQTT broker",
         nodeDetails = "Will publish message payload to the MQTT broker with QoS <b>AT_LEAST_ONCE</b>.",
         uiResources = {"static/rulenode/rulenode-core-config.js"},
diff --git a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/azure/TbAzureIotHubNode.java b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/azure/TbAzureIotHubNode.java
index 0b3d8f36ad..5720f66038 100644
--- a/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/azure/TbAzureIotHubNode.java
+++ b/rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/mqtt/azure/TbAzureIotHubNode.java
@@ -29,7 +29,7 @@ import org.thingsboard.rule.engine.credentials.ClientCredentials;
 import org.thingsboard.rule.engine.credentials.CredentialsType;
 import org.thingsboard.rule.engine.mqtt.TbMqttNode;
 import org.thingsboard.rule.engine.mqtt.TbMqttNodeConfiguration;
-import org.thingsboard.server.common.data.plugin.ComponentSingletonSupport;
+import org.thingsboard.server.common.data.plugin.ComponentClusteringMode;
 import org.thingsboard.server.common.data.plugin.ComponentType;
 
 import javax.net.ssl.SSLException;
@@ -39,7 +39,7 @@ import javax.net.ssl.SSLException;
         type = ComponentType.EXTERNAL,
         name = "azure iot hub",
         configClazz = TbAzureIotHubNodeConfiguration.class,
-        singleton = ComponentSingletonSupport.ONLY_SINGLETON,
+        clusteringMode = ComponentClusteringMode.SINGLETON,
         nodeDescription = "Publish messages to the Azure IoT Hub",
         nodeDetails = "Will publish message payload to the Azure IoT Hub with QoS <b>AT_LEAST_ONCE</b>.",
         uiResources = {"static/rulenode/rulenode-core-config.js"},
diff --git a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts
index 320ece312b..dad1e715ec 100644
--- a/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts
+++ b/ui-ngx/src/app/modules/home/pages/rulechain/rule-node-details.component.ts
@@ -26,7 +26,7 @@ import { RuleChainService } from '@core/http/rule-chain.service';
 import { RuleNodeConfigComponent } from './rule-node-config.component';
 import { Router } from '@angular/router';
 import { RuleChainType } from '@app/shared/models/rule-chain.models';
-import { ComponentSingletonSupport } from '@shared/models/component-descriptor.models';
+import { ComponentClusteringMode } from '@shared/models/component-descriptor.models';
 
 @Component({
   selector: 'tb-rule-node',
@@ -134,6 +134,6 @@ export class RuleNodeDetailsComponent extends PageComponent implements OnInit, O
   }
 
   isSingletonEditAllowed() {
-    return this.ruleNode.component.singleton === ComponentSingletonSupport.SUPPORTED;
+    return this.ruleNode.component.clusteringMode === ComponentClusteringMode.USER_PREFERENCE;
   }
 }
diff --git a/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts b/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts
index 9e68306ac4..7fff22a12a 100644
--- a/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts
+++ b/ui-ngx/src/app/modules/home/pages/rulechain/rulechain-page.component.ts
@@ -89,7 +89,7 @@ import { DebugEventType, EventType } from '@shared/models/event.models';
 import { MatMiniFabButton } from '@angular/material/button';
 import { TbPopoverService } from '@shared/components/popover.service';
 import { VersionControlComponent } from '@home/components/vc/version-control.component';
-import { ComponentSingletonSupport } from '@shared/models/component-descriptor.models';
+import { ComponentClusteringMode } from '@shared/models/component-descriptor.models';
 import Timeout = NodeJS.Timeout;
 
 @Component({
@@ -470,7 +470,7 @@ export class RuleChainPageComponent extends PageComponent
         component: ruleNodeComponent,
         name: '',
         nodeClass: desc.nodeClass,
-        singletonMode: ruleNodeComponent.singleton !== ComponentSingletonSupport.NOT_SUPPORTED,
+        singletonMode: ruleNodeComponent.clusteringMode !== ComponentClusteringMode.ENABLED,
         icon,
         iconUrl,
         x: 30,
diff --git a/ui-ngx/src/app/shared/models/component-descriptor.models.ts b/ui-ngx/src/app/shared/models/component-descriptor.models.ts
index d8e4aba2aa..3ce15d15aa 100644
--- a/ui-ngx/src/app/shared/models/component-descriptor.models.ts
+++ b/ui-ngx/src/app/shared/models/component-descriptor.models.ts
@@ -30,16 +30,16 @@ export enum ComponentScope {
   TENANT = 'TENANT'
 }
 
-export enum ComponentSingletonSupport {
-  SUPPORTED = 'SUPPORTED',
-  NOT_SUPPORTED = 'NOT_SUPPORTED',
-  ONLY_SINGLETON = 'ONLY_SINGLETON'
+export enum ComponentClusteringMode {
+  USER_PREFERENCE = 'USER_PREFERENCE',
+  ENABLED = 'ENABLED',
+  SINGLETON = 'SINGLETON'
 }
 
 export interface ComponentDescriptor {
   type: ComponentType | RuleNodeType;
   scope?: ComponentScope;
-  singleton: ComponentSingletonSupport;
+  clusteringMode: ComponentClusteringMode;
   name: string;
   clazz: string;
   configurationDescriptor?: any;
diff --git a/ui-ngx/src/app/shared/models/rule-chain.models.ts b/ui-ngx/src/app/shared/models/rule-chain.models.ts
index 57a58ba110..fbf6f57268 100644
--- a/ui-ngx/src/app/shared/models/rule-chain.models.ts
+++ b/ui-ngx/src/app/shared/models/rule-chain.models.ts
@@ -19,7 +19,7 @@ import { TenantId } from '@shared/models/id/tenant-id';
 import { RuleChainId } from '@shared/models/id/rule-chain-id';
 import { RuleNodeId } from '@shared/models/id/rule-node-id';
 import { RuleNode, RuleNodeComponentDescriptor, RuleNodeType } from '@shared/models/rule-node.models';
-import { ComponentSingletonSupport, ComponentType } from '@shared/models/component-descriptor.models';
+import { ComponentClusteringMode, ComponentType } from '@shared/models/component-descriptor.models';
 
 export interface RuleChain extends BaseData<RuleChainId>, ExportableEntity<RuleChainId> {
   tenantId: TenantId;
@@ -64,7 +64,7 @@ export const ruleNodeTypeComponentTypes: ComponentType[] =
 export const unknownNodeComponent: RuleNodeComponentDescriptor = {
   type: RuleNodeType.UNKNOWN,
   name: 'unknown',
-  singleton: ComponentSingletonSupport.NOT_SUPPORTED,
+  clusteringMode: ComponentClusteringMode.ENABLED,
   clazz: 'tb.internal.Unknown',
   configurationDescriptor: {
     nodeDefinition: {
@@ -81,7 +81,7 @@ export const unknownNodeComponent: RuleNodeComponentDescriptor = {
 
 export const inputNodeComponent: RuleNodeComponentDescriptor = {
   type: RuleNodeType.INPUT,
-  singleton: ComponentSingletonSupport.NOT_SUPPORTED,
+  clusteringMode: ComponentClusteringMode.ENABLED,
   name: 'Input',
   clazz: 'tb.internal.Input'
 };

From b5641a3c6c2e9c34cc5feebb6e04b83a0b604464 Mon Sep 17 00:00:00 2001
From: YevhenBondarenko <ybondarenko@thingsboard.io>
Date: Mon, 24 Apr 2023 19:49:17 +0200
Subject: [PATCH 09/11] refactored due to comments

---
 .../RuleNodeActorMessageProcessor.java        | 19 +++---
 .../service/RuleChainDataValidatorTest.java   | 66 -------------------
 .../server/dao/rule/BaseRuleChainService.java | 29 ++++++++
 .../validator/RuleChainDataValidator.java     | 17 -----
 4 files changed, 39 insertions(+), 92 deletions(-)
 delete mode 100644 application/src/test/java/org/thingsboard/server/service/RuleChainDataValidatorTest.java

diff --git a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
index 37964a8005..36e9113326 100644
--- a/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
+++ b/application/src/main/java/org/thingsboard/server/actors/ruleChain/RuleNodeActorMessageProcessor.java
@@ -60,7 +60,7 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
 
     @Override
     public void start(TbActorCtx context) throws Exception {
-        if (isMySingletonNode()) {
+        if (isMyNodePartition()) {
             tbNode = initComponent(ruleNode);
             if (tbNode != null) {
                 state = ComponentLifecycleState.ACTIVE;
@@ -70,7 +70,7 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
 
     @Override
     public void onUpdate(TbActorCtx context) throws Exception {
-        if (isMySingletonNode()) {
+        if (isMyNodePartition()) {
             RuleNode newRuleNode = systemContext.getRuleChainService().findRuleNodeById(tenantId, entityId);
             this.info = new RuleNodeInfo(entityId, ruleChainName, newRuleNode != null ? newRuleNode.getName() : "Unknown");
             boolean restartRequired = state != ComponentLifecycleState.ACTIVE ||
@@ -104,13 +104,13 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     @Override
     public void onPartitionChangeMsg(PartitionChangeMsg msg) throws Exception {
         if (tbNode != null) {
-            if (!isMySingletonNode()) {
+            if (!isMyNodePartition()) {
                 stop(null);
                 tbNode = null;
             } else {
                 tbNode.onPartitionChangeMsg(defaultCtx, msg);
             }
-        } else if (isMySingletonNode()) {
+        } else if (isMyNodePartition()) {
             start(null);
         }
     }
@@ -136,8 +136,8 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
     }
 
     void onRuleChainToRuleNodeMsg(RuleChainToRuleNodeMsg msg) throws Exception {
-        if (!isMySingletonNode()) {
-            putToQueue(msg.getMsg());
+        if (!isMyNodePartition()) {
+            putToNodePartition(msg.getMsg());
         } else {
             msg.getMsg().getCallback().onProcessingStart(info);
             checkComponentStateActive(msg.getMsg());
@@ -180,15 +180,16 @@ public class RuleNodeActorMessageProcessor extends ComponentMsgProcessor<RuleNod
         return new RuleNodeException("Rule Node is not active! Failed to initialize.", ruleChainName, ruleNode);
     }
 
-    private boolean isMySingletonNode() {
+    private boolean isMyNodePartition() {
         return !ruleNode.isSingletonMode()
                 || systemContext.getDiscoveryService().isMonolith()
                 || defaultCtx.isLocalEntity(ruleNode.getId());
     }
 
-    private void putToQueue(TbMsg source) {
+    //Message will return after processing. See RuleChainActorMessageProcessor.pushToTarget.
+    private void putToNodePartition(TbMsg source) {
         TbMsg tbMsg = TbMsg.newMsg(source, source.getQueueName(), source.getRuleChainId(), entityId);
-        TopicPartitionInfo tpi = systemContext.resolve(ServiceType.TB_RULE_ENGINE, tbMsg.getQueueName(), tenantId, entityId);
+        TopicPartitionInfo tpi = systemContext.resolve(ServiceType.TB_RULE_ENGINE, tbMsg.getQueueName(), tenantId, ruleNode.getId());
         TransportProtos.ToRuleEngineMsg toQueueMsg = TransportProtos.ToRuleEngineMsg.newBuilder()
                 .setTenantIdMSB(tenantId.getId().getMostSignificantBits())
                 .setTenantIdLSB(tenantId.getId().getLeastSignificantBits())
diff --git a/application/src/test/java/org/thingsboard/server/service/RuleChainDataValidatorTest.java b/application/src/test/java/org/thingsboard/server/service/RuleChainDataValidatorTest.java
deleted file mode 100644
index cc31a9f6ff..0000000000
--- a/application/src/test/java/org/thingsboard/server/service/RuleChainDataValidatorTest.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/**
- * Copyright © 2016-2023 The Thingsboard Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.thingsboard.server.service;
-
-import org.junit.Test;
-import org.junit.jupiter.api.Assertions;
-import org.thingsboard.common.util.JacksonUtil;
-import org.thingsboard.server.common.data.rule.RuleNode;
-import org.thingsboard.server.dao.exception.DataValidationException;
-import org.thingsboard.server.dao.service.validator.RuleChainDataValidator;
-
-public class RuleChainDataValidatorTest {
-
-    @Test
-    public void testSingletonSupport() {
-        String node = "org.thingsboard.rule.engine.mqtt.TbMqttNode";
-        RuleNode ruleNode = createRuleNode(node, false);
-        RuleChainDataValidator.validateRuleNode(ruleNode);
-        ruleNode.setSingletonMode(true);
-        RuleChainDataValidator.validateRuleNode(ruleNode);
-    }
-
-    @Test
-    public void testSingletonNotSupport() {
-        String node = "org.thingsboard.rule.engine.flow.TbAckNode";
-        RuleNode ruleNode = createRuleNode(node, false);
-        RuleChainDataValidator.validateRuleNode(ruleNode);
-        ruleNode.setSingletonMode(true);
-        Assertions.assertThrows(DataValidationException.class,
-                () -> RuleChainDataValidator.validateRuleNode(ruleNode),
-                String.format("Singleton mode not supported for [%s].", ruleNode.getType()));
-    }
-
-    @Test
-    public void testSingletonOnly() {
-        String node = "org.thingsboard.rule.engine.mqtt.azure.TbAzureIotHubNode";
-        RuleNode ruleNode = createRuleNode(node, true);
-        RuleChainDataValidator.validateRuleNode(ruleNode);
-        ruleNode.setSingletonMode(false);
-        Assertions.assertThrows(DataValidationException.class,
-                () -> RuleChainDataValidator.validateRuleNode(ruleNode),
-                String.format("Supported only singleton mode for [%s].", ruleNode.getType()));
-    }
-
-    private RuleNode createRuleNode(String type, boolean singletonMode) {
-        RuleNode ruleNode = new RuleNode();
-        ruleNode.setName("test node");
-        ruleNode.setType(type);
-        ruleNode.setSingletonMode(singletonMode);
-        ruleNode.setConfiguration(JacksonUtil.newObjectNode());
-        return ruleNode;
-    }
-}
diff --git a/dao/src/main/java/org/thingsboard/server/dao/rule/BaseRuleChainService.java b/dao/src/main/java/org/thingsboard/server/dao/rule/BaseRuleChainService.java
index 5a26715154..4b557d987c 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/rule/BaseRuleChainService.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/rule/BaseRuleChainService.java
@@ -38,6 +38,7 @@ import org.thingsboard.server.common.data.id.RuleNodeId;
 import org.thingsboard.server.common.data.id.TenantId;
 import org.thingsboard.server.common.data.page.PageData;
 import org.thingsboard.server.common.data.page.PageLink;
+import org.thingsboard.server.common.data.plugin.ComponentClusteringMode;
 import org.thingsboard.server.common.data.relation.EntityRelation;
 import org.thingsboard.server.common.data.relation.RelationTypeGroup;
 import org.thingsboard.server.common.data.rule.NodeConnectionInfo;
@@ -50,6 +51,7 @@ import org.thingsboard.server.common.data.rule.RuleChainType;
 import org.thingsboard.server.common.data.rule.RuleChainUpdateResult;
 import org.thingsboard.server.common.data.rule.RuleNode;
 import org.thingsboard.server.common.data.rule.RuleNodeUpdateResult;
+import org.thingsboard.server.common.data.util.ReflectionUtils;
 import org.thingsboard.server.dao.entity.AbstractEntityService;
 import org.thingsboard.server.dao.exception.DataValidationException;
 import org.thingsboard.server.dao.service.DataValidator;
@@ -146,6 +148,7 @@ public class BaseRuleChainService extends AbstractEntityService implements RuleC
         Map<RuleNodeId, Integer> ruleNodeIndexMap = new HashMap<>();
         if (nodes != null) {
             for (RuleNode node : nodes) {
+                setSingletonMode(node);
                 if (node.getId() != null) {
                     ruleNodeIndexMap.put(node.getId(), nodes.indexOf(node));
                 } else {
@@ -769,4 +772,30 @@ public class BaseRuleChainService extends AbstractEntityService implements RuleC
                 }
             };
 
+    private void setSingletonMode(RuleNode ruleNode) {
+        boolean singletonMode;
+        try {
+            ComponentClusteringMode nodeConfigType = ReflectionUtils.getAnnotationProperty(ruleNode.getType(),
+                    "org.thingsboard.rule.engine.api.RuleNode", "clusteringMode");
+
+            switch (nodeConfigType) {
+                case ENABLED:
+                    singletonMode = false;
+                    break;
+                case SINGLETON:
+                    singletonMode = true;
+                    break;
+                case USER_PREFERENCE:
+                default:
+                    singletonMode = ruleNode.isSingletonMode();
+                    break;
+            }
+        } catch (Exception e) {
+            log.warn("Failed to get clustering mode: {}", ExceptionUtils.getRootCauseMessage(e));
+            singletonMode = false;
+        }
+
+        ruleNode.setSingletonMode(singletonMode);
+    }
+
 }
diff --git a/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java b/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java
index 847acf69a2..5450e29706 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/service/validator/RuleChainDataValidator.java
@@ -25,7 +25,6 @@ import org.thingsboard.common.util.JacksonUtil;
 import org.thingsboard.server.common.data.EntityType;
 import org.thingsboard.server.common.data.StringUtils;
 import org.thingsboard.server.common.data.id.TenantId;
-import org.thingsboard.server.common.data.plugin.ComponentClusteringMode;
 import org.thingsboard.server.common.data.rule.NodeConnectionInfo;
 import org.thingsboard.server.common.data.rule.RuleChain;
 import org.thingsboard.server.common.data.rule.RuleChainMetaData;
@@ -113,22 +112,6 @@ public class RuleChainDataValidator extends DataValidator<RuleChain> {
             return;
         }
         ConstraintValidator.validateFields(nodeConfig, errorPrefix);
-
-        ComponentClusteringMode nodeConfigType = null;
-        try {
-            nodeConfigType = ReflectionUtils.getAnnotationProperty(ruleNode.getType(),
-                    "org.thingsboard.rule.engine.api.RuleNode", "clusteringMode");
-        } catch (Exception e) {
-            log.warn("Failed to validate singleton mode: {}", ExceptionUtils.getRootCauseMessage(e));
-            return;
-        }
-        if (ComponentClusteringMode.ENABLED.equals(nodeConfigType) && ruleNode.isSingletonMode()) {
-            throw new DataValidationException(String.format("Singleton mode not supported for [%s].", ruleNode.getType()));
-        }
-
-        if (ComponentClusteringMode.SINGLETON.equals(nodeConfigType) && !ruleNode.isSingletonMode()) {
-            throw new DataValidationException(String.format("Supported only singleton mode for [%s].", ruleNode.getType()));
-        }
     }
 
     private static void validateCircles(List<NodeConnectionInfo> connectionInfos) {

From 0168c791462a82a90853b17c94365741e1752542 Mon Sep 17 00:00:00 2001
From: YevhenBondarenko <ybondarenko@thingsboard.io>
Date: Mon, 24 Apr 2023 20:00:00 +0200
Subject: [PATCH 10/11] upgrade improvements

---
 application/src/main/data/upgrade/3.4.4/schema_update.sql | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/application/src/main/data/upgrade/3.4.4/schema_update.sql b/application/src/main/data/upgrade/3.4.4/schema_update.sql
index 0dc54a134f..4cb8c680d7 100644
--- a/application/src/main/data/upgrade/3.4.4/schema_update.sql
+++ b/application/src/main/data/upgrade/3.4.4/schema_update.sql
@@ -615,7 +615,7 @@ $$;
 
 ALTER TABLE rule_node ADD COLUMN IF NOT EXISTS singleton_mode bool DEFAULT false;
 
-UPDATE rule_node SET singleton_mode = true WHERE type IN ('org.thingsboard.rule.engine.mqtt.azure.TbAzureIotHubNode', 'org.thingsboard.rule.engine.mqtt.TbMqttNode');
+UPDATE rule_node SET singleton_mode = true WHERE type = 'org.thingsboard.rule.engine.mqtt.azure.TbAzureIotHubNode';
 
 ALTER TABLE component_descriptor ADD COLUMN IF NOT EXISTS clustering_mode varchar(255) DEFAULT 'ENABLED';
 

From dba203037fd33966c32c8f352d3e1867b30c118e Mon Sep 17 00:00:00 2001
From: YevhenBondarenko <ybondarenko@thingsboard.io>
Date: Tue, 25 Apr 2023 13:07:55 +0200
Subject: [PATCH 11/11] Added short doc for component clustering and added
 upgrade for mqtt node

---
 application/src/main/data/upgrade/3.4.4/schema_update.sql  | 2 +-
 .../server/common/data/plugin/ComponentClusteringMode.java | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/application/src/main/data/upgrade/3.4.4/schema_update.sql b/application/src/main/data/upgrade/3.4.4/schema_update.sql
index 4cb8c680d7..0dc54a134f 100644
--- a/application/src/main/data/upgrade/3.4.4/schema_update.sql
+++ b/application/src/main/data/upgrade/3.4.4/schema_update.sql
@@ -615,7 +615,7 @@ $$;
 
 ALTER TABLE rule_node ADD COLUMN IF NOT EXISTS singleton_mode bool DEFAULT false;
 
-UPDATE rule_node SET singleton_mode = true WHERE type = 'org.thingsboard.rule.engine.mqtt.azure.TbAzureIotHubNode';
+UPDATE rule_node SET singleton_mode = true WHERE type IN ('org.thingsboard.rule.engine.mqtt.azure.TbAzureIotHubNode', 'org.thingsboard.rule.engine.mqtt.TbMqttNode');
 
 ALTER TABLE component_descriptor ADD COLUMN IF NOT EXISTS clustering_mode varchar(255) DEFAULT 'ENABLED';
 
diff --git a/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentClusteringMode.java b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentClusteringMode.java
index 32eb43696c..8ebe277e0f 100644
--- a/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentClusteringMode.java
+++ b/common/data/src/main/java/org/thingsboard/server/common/data/plugin/ComponentClusteringMode.java
@@ -15,6 +15,13 @@
  */
 package org.thingsboard.server.common.data.plugin;
 
+/**
+ * The main idea to use this - it's adding the ability to start rule nodes in singleton mode in cluster setup
+ * (singleton rule node will start in only one Rule Engine instance)
+ * USER_PREFERENCE - user has ability to configure clustering mode (enable/disable singleton mode in rule node config)
+ * ENABLE - user doesn't have ability to configure clustering mode (singleton mode is always FALSE in rule node config)
+ * SINGLETON - user doesn't have ability to configure clustering mode (singleton mode is always TRUE in rule node config)
+ */
 public enum ComponentClusteringMode {
     USER_PREFERENCE,
     ENABLED,