Add test to ensure correct zk children cache invalidation (apache#14178)

pulsar-broker/src/test/java/org/apache/pulsar/broker/zookeeper/MultiBrokerMetadataConsistencyTest.java

@@ -0,0 +1,82 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.pulsar.broker.zookeeper;
+
+import static org.testng.Assert.assertTrue;
+import java.util.List;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.pulsar.broker.MultiBrokerBaseTest;
+import org.apache.pulsar.client.admin.PulsarAdmin;
+import org.apache.pulsar.client.admin.PulsarAdminException;
+import org.apache.pulsar.metadata.TestZKServer;
+import org.apache.pulsar.metadata.api.MetadataStoreConfig;
+import org.apache.pulsar.metadata.api.MetadataStoreException;
+import org.apache.pulsar.metadata.api.extended.MetadataStoreExtended;
+import org.testng.annotations.Test;
+
+@Slf4j
+@Test(groups = "broker")
+public class MultiBrokerMetadataConsistencyTest extends MultiBrokerBaseTest {
+    @Override
+    protected int numberOfAdditionalBrokers() {
+        return 2;
+    }
+
+    TestZKServer testZKServer;
+
+    @Override
+    protected void doInitConf() throws Exception {
+        super.doInitConf();
+        testZKServer = new TestZKServer();
+    }
+
+    @Override
+    protected void onCleanup() {
+        super.onCleanup();
+        if (testZKServer != null) {
+            try {
+                testZKServer.close();
+            } catch (Exception e) {
+                log.error("Error in stopping ZK server", e);
+            }
+        }
+    }
+
+    @Override
+    protected MetadataStoreExtended createLocalMetadataStore() throws MetadataStoreException {
+        return MetadataStoreExtended.create(testZKServer.getConnectionString(), MetadataStoreConfig.builder().build());
+    }
+
+    @Override
+    protected MetadataStoreExtended createConfigurationMetadataStore() throws MetadataStoreException {
+        return MetadataStoreExtended.create(testZKServer.getConnectionString(), MetadataStoreConfig.builder().build());
+    }
+
+    @Test
+    public void newTopicShouldBeInTopicsList() throws PulsarAdminException {
+        List<PulsarAdmin> admins = getAllAdmins();
+        PulsarAdmin first = admins.get(0);
+        PulsarAdmin second = admins.get(1);
+        List<String> cacheMiss = second.topics().getList("public/default");
+        assertTrue(cacheMiss.isEmpty());
+        first.topics().createNonPartitionedTopic("persistent://public/default/my-topic");
+        List<String> topics = second.topics().getList("public/default");
+        assertTrue(topics.contains("persistent://public/default/my-topic"));
+    }
+}