使用 Yarn 的注册表错误：服务注册表操作处于错误状态：初始化

Question

我正在尝试编写一个Yarn应用程序主机，它将自己提交到Yarn的注册表（Hadoop2.6）中

从本质上讲，这就是应用程序主程序试图做的事情：

ApplicationId id = ...
String path = ...
YarnConfiguration conf = new YarnConfiguration();    
RegistryOperations registryOperations = RegistryOperationsFactory.createInstance(conf);
ServiceRecord record = new ServiceRecord();
record.set(YarnRegistryAttributes.YARN_ID, applicationId);
record.set(YarnRegistryAttributes.YARN_PERSISTENCE,PersistencePolicies.APPLICATION_ATTEMPT);
registryOperations.bind(path, record, BindFlags.CREATE | BindFlags.OVERWRITE);

当将此代码提交给hadoop2.6时，我得到以下异常：

org.apache.hadoop.service.ServiceStateException: Service RegistryOperations is in wrong state: INITED
at org.apache.hadoop.registry.client.impl.zk.CuratorService.checkServiceLive(CuratorService.java:184)
at org.apache.hadoop.registry.client.impl.zk.CuratorService.zkSet(CuratorService.java:633)
at org.apache.hadoop.registry.client.impl.zk.RegistryOperationsService.bind(RegistryOperationsService.java:114)
...

在谷歌上搜索这个问题没有得到可用的结果，所以我尝试检查相关的Yarn的源代码——目前没有成功

还有人有这个问题吗？你知道是什么原因导致的，或者如何解决吗？

Answer 1

在读取RegistryOperationsFactory javadoc时，它说调用任何create*函数都将初始化生成的RegistryOperations实例。我不知道的是，当RegistryOperationsFactory初始化它时，它仍然需要启动。。所以这个代码有效：

ApplicationId id = ...
String path = ...
YarnConfiguration conf = new YarnConfiguration();    
RegistryOperations registryOperations = RegistryOperationsFactory.createInstance(conf);
registryOperations.start();
ServiceRecord record = new ServiceRecord();
record.set(YarnRegistryAttributes.YARN_ID, applicationId);
record.set(YarnRegistryAttributes.YARN_PERSISTENCE,PersistencePolicies.APPLICATION_ATTEMPT);
registryOperations.bind(path, record, BindFlags.CREATE | BindFlags.OVERWRITE);