设置重新分片标志

触发重新分配条件

• • 
    
• 新的实例加入
• /jobname/config文件变动
• 实例变动(加入、删除)
  • 
    

SetUpFacade

新节点启动的时候，会设置重新分片标志

registerStartUpInfo

public void registerStartUpInfo(final boolean enabled) {
        listenerManager.startAllListeners();
        leaderService.electLeader(); // 选取主节点
        serverService.persistOnline(enabled); //  /${jobname}/servers/192.16.67.21  设置ENABLED
        instanceService.persistOnline(); // 添加instances 比如: /${jobname}/instances/192.16.67.21@-@249736
        shardingService.setReshardingFlag(); //设置重新分片标志  jobName/leader/sharding/necessary
        if (!reconcileService.isRunning()) {
            reconcileService.startAsync();
        }
    }

ShardingListenerManager

public void start() { // 监听的是/jobName
    addDataListener(new ShardingTotalCountChangedJobListener());
    addDataListener(new ListenServersChangedJobListener());
}

ShardingTotalCountChangedJobListener

/jobname/config配置文件变动 触发

// /jobname/config配置文件变动 触发
class ShardingTotalCountChangedJobListener extends AbstractJobListener {

  @Override
  protected void dataChanged(final String path, final Type eventType, final String data) {
    if (configNode.isConfigPath(path) && 0 != JobRegistry.getInstance().getCurrentShardingTotalCount(jobName)) {
      int newShardingTotalCount = YamlEngine.unmarshal(data, JobConfigurationPOJO.class).toJobConfiguration().getShardingTotalCount(); // 新的分片数（配置文件变了）
      if (newShardingTotalCount != JobRegistry.getInstance().getCurrentShardingTotalCount(jobName)) { // 数量不一致
        shardingService.setReshardingFlag(); // 设置需要分片标志
        JobRegistry.getInstance().setCurrentShardingTotalCount(jobName, newShardingTotalCount); // 设置新的分片总数
      }
    }
  }
}

ListenServersChangedJobListener

// 任务服务器数量事件
class ListenServersChangedJobListener extends AbstractJobListener {

  @Override // jobname/instances下面有新增、删除节点触发 // NODE_CREATED  NODE_DELETED 要么有新的servers节点  或者 是否是服务器路径jobname/servers/${ip}
  protected void dataChanged(final String path, final Type eventType, final String data) {
    if (!JobRegistry.getInstance().isShutdown(jobName) && (isInstanceChange(eventType, path) || isServerChange(path))) {
      shardingService.setReshardingFlag();
    }
  }
  // isInstancePath: jobname/instances
  private boolean isInstanceChange(final Type eventType, final String path) {
    return instanceNode.isInstancePath(path) && Type.NODE_CHANGED != eventType; // NODE_CREATED  NODE_DELETED
  }

  private boolean isServerChange(final String path) {
    return serverNode.isServerPath(path);
  }
}