HelixUtils.java

/*
 * 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 gobblin.cluster;

import org.apache.helix.manager.zk.ZKHelixManager;
import org.apache.helix.model.HelixConfigScope;
import org.apache.helix.tools.ClusterSetup;

import gobblin.annotation.Alpha;


/**
 * A utility class for working with Gobblin on Helix.
 *
 * @author Yinan Li
 */
@Alpha
public class HelixUtils {

  /**
   * Create a Helix cluster for the Gobblin Cluster application.
   *
   * @param zkConnectionString the ZooKeeper connection string
   * @param clusterName the Helix cluster name
   */
  public static void createGobblinHelixCluster(String zkConnectionString, String clusterName) {
    createGobblinHelixCluster(zkConnectionString, clusterName, true);
  }

  /**
   * Create a Helix cluster for the Gobblin Cluster application.
   *
   * @param zkConnectionString the ZooKeeper connection string
   * @param clusterName the Helix cluster name
   * @param overwrite true to overwrite exiting cluster, false to reuse existing cluster
   */
  public static void createGobblinHelixCluster(String zkConnectionString, String clusterName, boolean overwrite) {
    ClusterSetup clusterSetup = new ClusterSetup(zkConnectionString);
    // Create the cluster and overwrite if it already exists
    clusterSetup.addCluster(clusterName, overwrite);
    // Helix 0.6.x requires a configuration property to have the form key=value.
    String autoJoinConfig = ZKHelixManager.ALLOW_PARTICIPANT_AUTO_JOIN + "=true";
    clusterSetup.setConfig(HelixConfigScope.ConfigScopeProperty.CLUSTER, clusterName, autoJoinConfig);
  }

  /**
   * Get a Helix instance name.
   *
   * @param namePrefix a prefix of Helix instance names
   * @param instanceId an integer instance ID
   * @return a Helix instance name that is a concatenation of the given prefix and instance ID
   */
  public static String getHelixInstanceName(String namePrefix, int instanceId) {
    return namePrefix + "_" + instanceId;
  }
}