nameservice1和nameservice2之间的差异

Question

我们使用的是带有Cloudera Manager 5的CDH 5.2。

我们希望将数据从nameservice2复制到nameservice1

两个集群在同一个CDH版本上

当我尝试hadoop distcp hdfs://nameservice2/foo/bar hdfs://nameservice1/bar/foo时

我弄错了

java.lang.IllegalArgumentException: java.net.UnknownHostException: nameservice2

因此，我从Nameservice2到Nameservice1添加了以下配置

Cloudera管理器(网关默认组)中hdfs-site.xml的HDFS客户端高级配置片段(安全阀)

<property>
<name>dfs.nameservices</name>
<value>nameservices2</value>
</property>
<property>
<name>dfs.client.failover.proxy.provider.nameservices2</name>
<value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider</value>
</property>
<property>
<name>dfs.ha.namenodes.nameservices2</name>
<value>namenode36,namenode405</value>
</property>
<property>
<name>dfs.namenode.rpc-address.nameservices2.namenode36</name>
<value>hnn001.prod.cc:8020</value>
</property>
<property>
<name>dfs.namenode.servicerpc-address.nameservices2.namenode36</name>
<value>hnn001.prod.com:54321</value>
</property>
<property>
<name>dfs.namenode.http-address.nameservices2.namenode36</name>
<value>hnn001.prod.com:50070</value>
</property>
<property>
<name>dfs.namenode.https-address.nameservices2.namenode36</name>
<value>hnn001.prod.com:50470</value>
</property>
<property>
<name>dfs.namenode.rpc-address.nameservices2.namenode405</name>
<value>hnn002.prod.com:8020</value>
</property>
<property>
<name>dfs.namenode.servicerpc-address.nameservices2.namenode405</name>
<value>hnn002.prod.com:54321</value>
</property>
<property>
<name>dfs.namenode.http-address.nameservices2.namenode405</name>
<value>hnn002.prod.com:50070</value>
</property>
<property>
<name>dfs.namenode.https-address.nameservices2.namenode405</name>
<value>hnn002.prod.com:50470</value>
</property>

但我仍然收到相同的错误。

有什么解决方法吗？

谢谢

Answer 1

在启用HA的HDFS namenode nameservice1中，nameservice2是逻辑名称，您不能将端口与该逻辑名称一起使用。

您有两种方法。

简单的方法是找到活动的namenode，并在distcp命令中使用活动的namenode:port，如下所示。Namenode web UI可用于查找两个群集的活动名称节点。

hadoop distcp hdfs://hnn001.prod.cc:8020:8020/foo/bar hdfs://<dest-cluster-active-nn-hostname>:8020/bar/foo

另一种方法是使用两个集群的逻辑名称，如下所示，但在尝试以下命令之前，请确保您已经在客户端hdfs-site.xml中正确配置了nameservice1和nameservice2。

hadoop distcp hdfs://nameservice2/foo/bar hdfs://nameservice1/bar/foo

正在本地群集中确认远程群集的命名服务。

看起来nameservice2是你的本地，nameservice1是你的遥控器。您需要将nameservice1和nameservice2的所有关联属性保留在本地集群中。本地群集的客户端hdfs-site.xml文件应如下所示。

<configuration>
<!-- Available nameservices -->
<property>
<name>dfs.nameservices</name>
<value>nameservices1,nameservices2</value>
</property>

<!-- Local nameservice2 properties -->
<property>
<name>dfs.client.failover.proxy.provider.nameservices2</name>
<value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider</value>
</property>
<property>
<name>dfs.ha.namenodes.nameservices2</name>
<value>namenode36,namenode405</value>
</property>
<property>
<name>dfs.namenode.rpc-address.nameservices2.namenode36</name>
<value>hnn001.prod.cc:8020</value>
</property>
<property>
<name>dfs.namenode.servicerpc-address.nameservices2.namenode36</name>
<value>hnn001.prod.com:54321</value>
</property>
<property>
<name>dfs.namenode.http-address.nameservices2.namenode36</name>
<value>hnn001.prod.com:50070</value>
</property>
<property>
<name>dfs.namenode.https-address.nameservices2.namenode36</name>
<value>hnn001.prod.com:50470</value>
</property>
<property>
<name>dfs.namenode.rpc-address.nameservices2.namenode405</name>
<value>hnn002.prod.com:8020</value>
</property>
<property>
<name>dfs.namenode.servicerpc-address.nameservices2.namenode405</name>
<value>hnn002.prod.com:54321</value>
</property>
<property>
<name>dfs.namenode.http-address.nameservices2.namenode405</name>
<value>hnn002.prod.com:50070</value>
</property>
<property>
<name>dfs.namenode.https-address.nameservices2.namenode405</name>
<value>hnn002.prod.com:50470</value>
</property>

<!-- Remote nameservice1 properties -->
<!-- You can find these properties in the remote machine's hdfs-site.xml file -->

<property>
<name>dfs.client.failover.proxy.provider.nameservices1</name>
<value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider</value>
</property>
<property>
<name>dfs.ha.namenodes.nameservices1</name>
<value>namenodeXX,namenodeYY</value>
</property>
<property>
<name>dfs.namenode.rpc-address.nameservices1.namenodeXX</name>
<value><Remote-nn1>:8020</value>
</property>
<property>
<name>dfs.namenode.servicerpc-address.nameservices1.namenodeXX</name>
<value><Remote-nn1>:54321</value>
</property>
<property>
<name>dfs.namenode.http-address.nameservices1.namenode**XX**</name>
<value><Remote-nn1>:50070</value>
</property>
<property>
<name>dfs.namenode.https-address.nameservices1.namenodeXX</name>
<value><Remote-nn1>:50470</value>
</property>
<property>
<name>dfs.namenode.rpc-address.nameservices1.namenodeYY</name>
<value><Remote-nn2>:8020</value>
</property>
<property>
<name>dfs.namenode.servicerpc-address.nameservices1.namenodeYY</name>
<value><Remote-nn2>:54321</value>
</property>
<property>
<name>dfs.namenode.http-address.nameservices1.namenodeYY</name>
<value><Remote-nn2>:50070</value>
</property>
<property>
<name>dfs.namenode.https-address.nameservices1.namenodeYY</name>
<value><Remote-nn2>:50470</value>
</property>

<!-- Other properties --> 

</configuration>

在上面的配置文件中，用远程机器的hdfs site.xml中的相应值替换所有的占位符，比如YY。