Fix: apply queue prefix when creating Kafka topics to prevent orphaned topics

application/src/main/java/org/thingsboard/server/service/entitiy/queue/DefaultTbQueueService.java

@@ -27,6 +27,7 @@ import org.thingsboard.server.common.data.tenant.profile.TenantProfileQueueConfi
 import org.thingsboard.server.common.msg.queue.TopicPartitionInfo;
 import org.thingsboard.server.dao.queue.QueueService;
 import org.thingsboard.server.queue.TbQueueAdmin;
+import org.thingsboard.server.queue.discovery.TopicService;
 import org.thingsboard.server.queue.util.TbCoreComponent;
 import org.thingsboard.server.service.entitiy.AbstractTbEntityService;
 
@@ -45,6 +46,7 @@ public class DefaultTbQueueService extends AbstractTbEntityService implements Tb
     private final QueueService queueService;
     private final TbClusterService tbClusterService;
     private final TbQueueAdmin tbQueueAdmin;
+    private final TopicService topicService;
 
     @Override
     public Queue saveQueue(Queue queue) {
@@ -173,9 +175,10 @@ public class DefaultTbQueueService extends AbstractTbEntityService implements Tb
     private void createTopicsIfNeeded(Queue queue, Queue oldQueue) {
         int newPartitions = queue.getPartitions();
         int oldPartitions = oldQueue != null ? oldQueue.getPartitions() : 0;
+        String prefixedTopic = topicService.buildTopicName(queue.getTopic());
         for (int i = oldPartitions; i < newPartitions; i++) {
             tbQueueAdmin.createTopicIfNotExists(
-                    new TopicPartitionInfo(queue.getTopic(), queue.getTenantId(), i, false).getFullTopicName(),
+                    new TopicPartitionInfo(prefixedTopic, queue.getTenantId(), i, false).getFullTopicName(),
                     queue.getCustomProperties(),
                     true); // forcing topic creation because the topic may still be cached on some nodes
         }

application/src/test/java/org/thingsboard/server/service/entitiy/queue/DefaultTbQueueServiceTest.java

@@ -0,0 +1,141 @@
+/**
+ * Copyright © 2016-2026 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.entitiy.queue;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.test.util.ReflectionTestUtils;
+import org.thingsboard.server.cluster.TbClusterService;
+import org.thingsboard.server.common.data.id.QueueId;
+import org.thingsboard.server.common.data.id.TenantId;
+import org.thingsboard.server.common.data.queue.Queue;
+import org.thingsboard.server.dao.queue.QueueService;
+import org.thingsboard.server.queue.TbQueueAdmin;
+import org.thingsboard.server.queue.discovery.TopicService;
+
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyBoolean;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+public class DefaultTbQueueServiceTest {
+
+    @Mock
+    private QueueService queueServiceMock;
+    @Mock
+    private TbClusterService tbClusterServiceMock;
+    @Mock
+    private TbQueueAdmin tbQueueAdminMock;
+
+    private TopicService topicService;
+    private DefaultTbQueueService tbQueueService;
+
+    private final TenantId tenantId = TenantId.SYS_TENANT_ID;
+
+    @BeforeEach
+    public void setUp() {
+        topicService = new TopicService();
+        tbQueueService = new DefaultTbQueueService(queueServiceMock, tbClusterServiceMock, tbQueueAdminMock, topicService);
+    }
+
+    private Queue newQueue(int partitions) {
+        Queue queue = new Queue();
+        queue.setTenantId(tenantId);
+        queue.setName("testQueue");
+        queue.setTopic("tb_rule_engine.testQueue");
+        queue.setPartitions(partitions);
+        return queue;
+    }
+
+    @Test
+    public void givenQueuePrefix_whenSaveQueue_thenCreatesPrefixedTopics() {
+        // queue.prefix = "thingsboard" (TB_QUEUE_PREFIX set)
+        ReflectionTestUtils.setField(topicService, "prefix", "thingsboard");
+
+        Queue queue = newQueue(2);
+        when(queueServiceMock.saveQueue(queue)).thenReturn(queue);
+
+        tbQueueService.saveQueue(queue);
+
+        ArgumentCaptor<String> topicCaptor = ArgumentCaptor.forClass(String.class);
+        verify(tbQueueAdminMock, times(2)).createTopicIfNotExists(topicCaptor.capture(), any(), anyBoolean());
+
+        // All created topics must carry the prefix - this is the fix.
+        assertThat(topicCaptor.getAllValues())
+                .containsExactlyInAnyOrder(
+                        "thingsboard.tb_rule_engine.testQueue.0",
+                        "thingsboard.tb_rule_engine.testQueue.1");
+        // No unprefixed (orphan-prone) topic must ever be created.
+        assertThat(topicCaptor.getAllValues())
+                .noneMatch(topic -> topic.equals("tb_rule_engine.testQueue.0")
+                        || topic.equals("tb_rule_engine.testQueue.1"));
+    }
+
+    @Test
+    public void givenNoQueuePrefix_whenSaveQueue_thenCreatesUnprefixedTopics() {
+        // queue.prefix blank (TB_QUEUE_PREFIX not set) - default behavior preserved
+        ReflectionTestUtils.setField(topicService, "prefix", "");
+
+        Queue queue = newQueue(2);
+        when(queueServiceMock.saveQueue(queue)).thenReturn(queue);
+
+        tbQueueService.saveQueue(queue);
+
+        ArgumentCaptor<String> topicCaptor = ArgumentCaptor.forClass(String.class);
+        verify(tbQueueAdminMock, times(2)).createTopicIfNotExists(topicCaptor.capture(), any(), anyBoolean());
+
+        assertThat(topicCaptor.getAllValues())
+                .containsExactlyInAnyOrder(
+                        "tb_rule_engine.testQueue.0",
+                        "tb_rule_engine.testQueue.1");
+    }
+
+    @Test
+    public void givenQueuePrefix_whenIncreasePartitions_thenOnlyNewPartitionsCreatedPrefixed() {
+        ReflectionTestUtils.setField(topicService, "prefix", "thingsboard");
+
+        Queue oldQueue = newQueue(2);
+        oldQueue.setId(new QueueId(UUID.randomUUID()));
+        Queue updatedQueue = newQueue(4);
+        updatedQueue.setId(oldQueue.getId());
+
+        when(queueServiceMock.findQueueById(tenantId, updatedQueue.getId())).thenReturn(oldQueue);
+        when(queueServiceMock.saveQueue(updatedQueue)).thenReturn(updatedQueue);
+
+        tbQueueService.saveQueue(updatedQueue);
+
+        ArgumentCaptor<String> topicCaptor = ArgumentCaptor.forClass(String.class);
+        verify(tbQueueAdminMock, times(2)).createTopicIfNotExists(topicCaptor.capture(), any(), anyBoolean());
+
+        assertThat(topicCaptor.getAllValues())
+                .containsExactlyInAnyOrder(
+                        "thingsboard.tb_rule_engine.testQueue.2",
+                        "thingsboard.tb_rule_engine.testQueue.3");
+        verify(tbQueueAdminMock, never()).createTopicIfNotExists(eq("thingsboard.tb_rule_engine.testQueue.0"), any(), anyBoolean());
+    }
+
+}