content: /*
   * Copyright (C) 2010-2101 Alibaba Group Holding Limited.
   *
   * Licensed 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 com.alibaba.otter.shared.arbitrate.impl.manage;
  
  import org.I0Itec.zkclient.exception.ZkBadVersionException;
  import org.I0Itec.zkclient.exception.ZkException;
  import org.I0Itec.zkclient.exception.ZkNoNodeException;
  import org.I0Itec.zkclient.exception.ZkNodeExistsException;
  import org.apache.zookeeper.CreateMode;
  import org.apache.zookeeper.data.Stat;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.alibaba.otter.shared.arbitrate.exception.ArbitrateException;
  import com.alibaba.otter.shared.arbitrate.impl.ArbitrateEvent;
  import com.alibaba.otter.shared.arbitrate.impl.manage.helper.ManagePathUtils;
  import com.alibaba.otter.shared.arbitrate.impl.zookeeper.ZooKeeperClient;
  import com.alibaba.otter.shared.arbitrate.model.MainStemEventData;
  import com.alibaba.otter.shared.common.utils.JsonUtils;
  import com.alibaba.otter.shared.common.utils.zookeeper.ZkClientx;
  
  /**
   * otter系统节点初始化
   * 
   * @author jianghang 2012-2-16 下午04:38:33
   * @version 4.0.0
   */
  public class SystemArbitrateEvent implements ArbitrateEvent {
  
      private static final Logger logger    = LoggerFactory.getLogger(SystemArbitrateEvent.class);
      private ZkClientx           zookeeper = ZooKeeperClient.getInstance();
  
      /**
       * 初始化对应的系统节点,同步调用
       */
      public void init() {
          String rootPath = ManagePathUtils.getRoot();
          String channelRootPath = ManagePathUtils.getChannelRoot();
          String nodeRootPath = ManagePathUtils.getNodeRoot();
          try {
              zookeeper.create(rootPath, new byte[0], CreateMode.PERSISTENT);
              zookeeper.create(channelRootPath, new byte[0], CreateMode.PERSISTENT);
              zookeeper.create(nodeRootPath, new byte[0], CreateMode.PERSISTENT);
          } catch (ZkNodeExistsException e) {
              // 如果节点已经存在，则不抛异常
              // ignore
          } catch (ZkException e) {
              throw new ArbitrateException("system_init", e);
          }
      }
  
      /**
       * 销毁对应的系统节点,同步调用
       */
      public void destory() {
          String rootPath = ManagePathUtils.getRoot();
          String channelRootPath = ManagePathUtils.getChannelRoot();
          String nodeRootPath = ManagePathUtils.getNodeRoot();
          try {
              zookeeper.deleteRecursive(channelRootPath); // 删除节点，不关心版本
              zookeeper.deleteRecursive(nodeRootPath); // 删除节点，不关心版本
              zookeeper.deleteRecursive(rootPath); // 删除节点，不关心版本
          } catch (ZkNoNodeException e) {
              // 如果节点已经不存在，则不抛异常
              // ignore
          } catch (ZkException e) {
              throw new ArbitrateException("system_destory", e);
          }
      }
  
      /**
       * 手工触发一次主备切换
       */
      public void switchWarmup(Long channelId, Long pipelineId) {
          String path = ManagePathUtils.getMainStem(channelId, pipelineId);
          try {
              while (true) {
                  Stat stat = new Stat();
                  byte[] bytes = zookeeper.readData(path, stat);
                  MainStemEventData mainStemData = JsonUtils.unmarshalFromByte(bytes, MainStemEventData.class);
                  mainStemData.setActive(false);
                  try {
                      zookeeper.writeData(path, JsonUtils.marshalToByte(mainStemData), stat.getVersion());
                      logger.warn("relase channelId[{}],pipelineId[{}] mainstem successed! ", channelId, pipelineId);
                      break;
                  } catch (ZkBadVersionException e) {
                      // ignore , retrying
                  }
              }
          } catch (ZkNoNodeException e) {
              // ignore
          } catch (ZkException e) {
              throw new ArbitrateException("releaseMainStem", pipelineId.toString(), e);
          }
      }
  }
  