PIP-121: Pulsar cluster level auto failover on client side

pulsar-client-api/src/main/java/org/apache/pulsar/client/api/AutoClusterFailoverBuilder.java

@@ -0,0 +1,128 @@
+/**
+ * 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.client.api;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import org.apache.pulsar.common.classification.InterfaceAudience;
+import org.apache.pulsar.common.classification.InterfaceStability;
+
+/**
+ * {@link AutoClusterFailoverBuilder} is used to configure and create instance of {@link ServiceUrlProvider}.
+ *
+ * @since 2.10.0
+ */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public interface AutoClusterFailoverBuilder {
+
+    @SuppressWarnings("checkstyle:javadoctype")
+    enum FailoverPolicy {
+        ORDER
+    }
+    /**
+     * Set the primary service url.
+     *
+     * @param primary
+     * @return
+     */
+    AutoClusterFailoverBuilder primary(String primary);
+
+    /**
+     * Set the secondary service url.
+     *
+     * @param secondary
+     * @return
+     */
+    AutoClusterFailoverBuilder secondary(List<String> secondary);
+
+    /**
+     * Set secondary choose policy. The default secondary choose policy is `ORDER`.
+     * @param policy
+     * @return
+     */
+    AutoClusterFailoverBuilder failoverPolicy(FailoverPolicy policy);
+
+    /**
+     * Set secondary authentication.
+     *
+     * @param authentication
+     * @return
+     */
+    AutoClusterFailoverBuilder secondaryAuthentication(Map<String, Authentication> authentication);
+
+    /**
+     * Set secondary tlsTrustCertsFilePath.
+     *
+     * @param tlsTrustCertsFilePath
+     * @return
+     */
+    AutoClusterFailoverBuilder secondaryTlsTrustCertsFilePath(Map<String, String> tlsTrustCertsFilePath);
+
+    /**
+     * Set secondary tlsTrustStorePath.
+     *
+     * @param tlsTrustStorePath
+     * @return
+     */
+    AutoClusterFailoverBuilder secondaryTlsTrustStorePath(Map<String, String> tlsTrustStorePath);
+
+    /**
+     * Set secondary tlsTrustStorePassword.
+     *
+     * @param tlsTrustStorePassword
+     * @return
+     */
+    AutoClusterFailoverBuilder secondaryTlsTrustStorePassword(Map<String, String> tlsTrustStorePassword);
+    /**
+     * Set the switch failoverDelay. When one cluster failed longer than failoverDelay, it will trigger cluster switch.
+     *
+     * @param failoverDelay
+     * @param timeUnit
+     * @return
+     */
+    AutoClusterFailoverBuilder failoverDelay(long failoverDelay, TimeUnit timeUnit);
+
+    /**
+     * Set the switchBackDelay. When switched to the secondary cluster, and after the primary cluster comes back,
+     * it will wait for switchBackDelay to switch back to the primary cluster.
+     *
+     * @param switchBackDelay
+     * @param timeUnit
+     * @return
+     */
+    AutoClusterFailoverBuilder switchBackDelay(long switchBackDelay, TimeUnit timeUnit);
+
+    /**
+     * Set the checkInterval for probe.
+     *
+     * @param interval
+     * @param timeUnit
+     * @return
+     */
+    AutoClusterFailoverBuilder checkInterval(long interval, TimeUnit timeUnit);
+
+    /**
+     * Build the ServiceUrlProvider instance.
+     *
+     * @return
+     */
+    ServiceUrlProvider build();
+}

pulsar-client-api/src/main/java/org/apache/pulsar/client/api/ControlledClusterFailoverBuilder.java

@@ -0,0 +1,73 @@
+/**
+ * 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.client.api;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import org.apache.pulsar.common.classification.InterfaceAudience;
+import org.apache.pulsar.common.classification.InterfaceStability;
+
+/**
+ * {@link ControlledClusterFailoverBuilder} is used to configure and create instance of {@link ServiceUrlProvider}.
+ *
+ * @since 2.10.0
+ */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public interface ControlledClusterFailoverBuilder {
+    /**
+     * Set default service url.
+     *
+     * @param serviceUrl
+     * @return
+     */
+    ControlledClusterFailoverBuilder defaultServiceUrl(String serviceUrl);
+
+    /**
+     * Set the service url provider. ServiceUrlProvider will fetch serviceUrl from urlProvider periodically.
+     *
+     * @param urlProvider
+     * @return
+     */
+    ControlledClusterFailoverBuilder urlProvider(String urlProvider);
+
+    /**
+     * Set the service url provider header to authenticate provider service.
+     * @param header
+     * @return
+     */
+    ControlledClusterFailoverBuilder urlProviderHeader(Map<String, String> header);
+
+    /**
+     * Set the probe check interval.
+     * @param interval
+     * @param timeUnit
+     * @return
+     */
+    ControlledClusterFailoverBuilder checkInterval(long interval, TimeUnit timeUnit);
+
+    /**
+     * Build the ServiceUrlProvider instance.
+     *
+     * @return
+     * @throws IOException
+     */
+    ServiceUrlProvider build() throws IOException;
+}

pulsar-client-api/src/main/java/org/apache/pulsar/client/api/ServiceUrlProvider.java

@@ -31,7 +31,7 @@
  */
 @InterfaceAudience.Public
 @InterfaceStability.Stable
-public interface ServiceUrlProvider {
+public interface ServiceUrlProvider extends AutoCloseable {
 
     /**
      * Initialize the service url provider with Pulsar client instance.
@@ -51,4 +51,12 @@ public interface ServiceUrlProvider {
      */
     String getServiceUrl();
 
+    /**
+     * Close the resource that the provider allocated.
+     *
+     */
+    @Override
+    default void close() {
+        // do nothing
+    }
 }