| /* |
| * 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.samza.zk; |
| |
| import com.google.common.base.Strings; |
| import org.I0Itec.zkclient.ZkClient; |
| import org.apache.samza.SamzaException; |
| import org.apache.samza.config.ApplicationConfig; |
| import org.apache.samza.config.Config; |
| import org.apache.samza.config.ZkConfig; |
| import org.apache.samza.coordinator.CoordinationUtils; |
| import org.apache.samza.coordinator.CoordinationUtilsFactory; |
| import org.apache.samza.util.NoOpMetricsRegistry; |
| import org.apache.zookeeper.client.ConnectStringParser; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| |
| public class ZkCoordinationUtilsFactory implements CoordinationUtilsFactory { |
| private static final Logger LOG = LoggerFactory.getLogger(ZkCoordinationUtilsFactory.class); |
| |
| public CoordinationUtils getCoordinationUtils(String coordinationId, String participantId, Config config) { |
| String groupId = new ApplicationConfig(config).getGlobalAppId() + "/" + coordinationId; |
| ZkConfig zkConfig = new ZkConfig(config); |
| |
| ZkClient zkClient = |
| createZkClient(zkConfig.getZkConnect(), zkConfig.getZkSessionTimeoutMs(), zkConfig.getZkConnectionTimeoutMs()); |
| |
| ZkUtils zkUtils = new ZkUtils(new ZkKeyBuilder(groupId), zkClient, zkConfig.getZkConnectionTimeoutMs(), zkConfig.getZkSessionTimeoutMs(), |
| new NoOpMetricsRegistry()); |
| return new ZkCoordinationUtils(participantId, zkConfig, zkUtils); |
| } |
| |
| /** |
| * helper method to create zkClient |
| * @param connectString - zkConnect string |
| * @param sessionTimeoutMS - session timeout |
| * @param connectionTimeoutMs - connection timeout |
| * @return zkClient object |
| */ |
| public static ZkClient createZkClient(String connectString, int sessionTimeoutMS, int connectionTimeoutMs) { |
| ZkClient zkClient; |
| try { |
| zkClient = new ZkClient(connectString, sessionTimeoutMS, connectionTimeoutMs, new ZkStringSerializer(), connectionTimeoutMs); |
| } catch (Exception e) { |
| // ZkClient constructor may throw a variety of different exceptions, not all of them Zk based. |
| throw new SamzaException("zkClient failed to connect to ZK at :" + connectString, e); |
| } |
| |
| // make sure the namespace in zk exists (if specified) |
| validateZkNameSpace(connectString, zkClient); |
| |
| return zkClient; |
| } |
| |
| /** |
| * if ZkConnectString contains namespace path at the end, but it does not exist we should fail |
| * @param zkConnect - connect string |
| * @param zkClient - zkClient object to talk to the ZK |
| */ |
| public static void validateZkNameSpace(String zkConnect, ZkClient zkClient) { |
| ConnectStringParser parser = new ConnectStringParser(zkConnect); |
| |
| String path = parser.getChrootPath(); |
| if (Strings.isNullOrEmpty(path)) { |
| return; // no namespace path |
| } |
| |
| LOG.info("connectString = " + zkConnect + "; path =" + path); |
| |
| // if namespace specified (path above) but "/" does not exists, we will fail |
| if (!zkClient.exists("/")) { |
| throw new SamzaException("Zookeeper namespace: " + path + " does not exist for zk at " + zkConnect); |
| } |
| } |
| |
| } |