| package org.apache.helix; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.Properties; |
| |
| import org.apache.helix.model.CloudConfig; |
| import org.apache.helix.msdcommon.exception.InvalidRoutingDataException; |
| import org.apache.helix.zookeeper.api.client.HelixZkClient; |
| import org.apache.helix.zookeeper.api.client.RealmAwareZkClient; |
| import org.apache.helix.zookeeper.datamodel.serializer.ZNRecordSerializer; |
| import org.apache.helix.zookeeper.impl.factory.DedicatedZkClientFactory; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| |
| /** |
| * Singleton factory that builds different types of Helix property, e.g. Helix manager property. |
| */ |
| public final class HelixPropertyFactory { |
| private static final Logger LOG = LoggerFactory.getLogger(HelixPropertyFactory.class); |
| private static final String HELIX_PARTICIPANT_PROPERTY_FILE = |
| SystemPropertyKeys.HELIX_MANAGER_PROPERTIES; |
| |
| private static class SingletonHelper { |
| private static final HelixPropertyFactory INSTANCE = new HelixPropertyFactory(); |
| } |
| |
| public static HelixPropertyFactory getInstance() { |
| return SingletonHelper.INSTANCE; |
| } |
| |
| /** |
| * Retrieve Helix manager property. It returns the property object with default values. |
| * Clients may override these values. |
| */ |
| public HelixManagerProperty getHelixManagerProperty(String zkAddress, String clusterName) { |
| CloudConfig cloudConfig = getCloudConfig(zkAddress, clusterName); |
| Properties properties = new Properties(); |
| try { |
| InputStream stream = Thread.currentThread().getContextClassLoader() |
| .getResourceAsStream(HELIX_PARTICIPANT_PROPERTY_FILE); |
| properties.load(stream); |
| } catch (IOException e) { |
| String errMsg = String.format("failed to open Helix participant properties file: %s", |
| HELIX_PARTICIPANT_PROPERTY_FILE); |
| throw new IllegalArgumentException(errMsg, e); |
| } |
| LOG.info("HelixPropertyFactory successfully loaded helix participant properties: {}", |
| properties); |
| return new HelixManagerProperty(properties, cloudConfig); |
| } |
| |
| private static CloudConfig buildEmptyCloudConfig() { |
| return new CloudConfig.Builder().setCloudEnabled(false).build(); |
| } |
| |
| /** |
| * Retrieve the CloudConfig of the cluster if available. |
| * Note: the reason we create a dedicated zk client here is because we need an isolated access to |
| * ZK in order to create a HelixManager instance. |
| * If shared zk client instance is used, this logic may break if users write tests that shut down |
| * ZK server and start again at a 0 zxid because the shared client would have a higher zxid. |
| * @param zkAddress |
| * @param clusterName |
| * @return |
| */ |
| private CloudConfig getCloudConfig(String zkAddress, String clusterName) { |
| CloudConfig cloudConfig; |
| RealmAwareZkClient dedicatedZkClient = null; |
| try { |
| if (Boolean.getBoolean(SystemPropertyKeys.MULTI_ZK_ENABLED) || zkAddress == null) { |
| // If the multi ZK config is enabled or zkAddress is null, use realm-aware mode with |
| // DedicatedZkClient |
| try { |
| RealmAwareZkClient.RealmAwareZkConnectionConfig connectionConfig = |
| new RealmAwareZkClient.RealmAwareZkConnectionConfig.Builder() |
| .setRealmMode(RealmAwareZkClient.RealmMode.SINGLE_REALM) |
| .setZkRealmShardingKey("/" + clusterName).build(); |
| dedicatedZkClient = |
| DedicatedZkClientFactory.getInstance().buildZkClient(connectionConfig); |
| } catch (IOException | InvalidRoutingDataException e) { |
| throw new HelixException("Not able to connect on multi-ZK mode!", e); |
| } |
| } else { |
| // Use a dedicated ZK client single-ZK mode |
| HelixZkClient.ZkConnectionConfig connectionConfig = |
| new HelixZkClient.ZkConnectionConfig(zkAddress); |
| dedicatedZkClient = DedicatedZkClientFactory.getInstance().buildZkClient(connectionConfig); |
| } |
| dedicatedZkClient.setZkSerializer(new ZNRecordSerializer()); |
| ConfigAccessor configAccessor = new ConfigAccessor(dedicatedZkClient); |
| |
| // The try-catch logic is for backward compatibility reason only. Even if the cluster is not set |
| // up yet, constructing a new ZKHelixManager should not throw an exception |
| try { |
| cloudConfig = configAccessor.getCloudConfig(clusterName) == null ? buildEmptyCloudConfig() |
| : configAccessor.getCloudConfig(clusterName); |
| } catch (HelixException e) { |
| cloudConfig = buildEmptyCloudConfig(); |
| } |
| } finally { |
| // Use a try-finally to make sure zkclient connection is closed properly |
| if (dedicatedZkClient != null && !dedicatedZkClient.isClosed()) { |
| dedicatedZkClient.close(); |
| } |
| } |
| return cloudConfig; |
| } |
| } |