Apache Hadoop 2.7.3，套接字超时错误

Question

我遇到了与以下链接相同的问题。

Hadoop, Socket Timeout Error

您能帮我解决一下吗，我在安装 Apache Hadoop 2.7.3 EC2 时遇到了同样的问题。链接中提到的属性是否需要同时添加到名称和数据节点配置文件中？如果是，所有 .xmls 是什么？提前致谢。

此外，应用程序正在尝试按照以下错误访问 EC2 上的内部 ip，我需要打开任何端口吗？它在 Web UI 上显示 8042。

所有节点和 Nodemanager 和 Resource Manager(RM) 都显示在 jps 上运行。

当我尝试运行 map reduce 示例时来自 Namenode 的错误如下：

作业 job_1506038808044_0002 失败，状态为 FAILED，原因是：应用程序 application_1506038808044_0002 由于启动 appattempt_1506038808044_0002_000002 时出错而失败了 2 次。得到异常：org.apache.hadoop.net.ConnectTimeoutException：从 ip-172-31-1-10/172.31.1.10 调用到 ip-172-31-5-59.ec2.internal:43555 在套接字超时异常上失败： org.apache.hadoop.net.ConnectTimeoutException：等待通道准备好连接时超时 20000 毫秒。 ch : java.nio.channels.SocketChannel[connection-pending remote=ip-172-31-5-59.ec2.internal/172.31.5.59:43555]

最后，RM Web UI 在作业运行时始终显示以下消息：

状态：等待 AM 容器分配、启动和注册到 RM。

谢谢， 阿莎

Answer 1

在尝试了 Hadoop 上的解决方案后，Socket Timeout Error（我的问题中的链接）并将下面添加到 hdfs-site.xml 文件中，通过允许所有 ICMP 和 UDP 规则到 ec2 实例以便他们可以 ping 解决了问题彼此之间。

<property>
  <name>dfs.namenode.name.dir</name>
  <value>/usr/local/hadoop/hadoop_work/hdfs/namenode</value>
</property>
<property>
  <name>dfs.datanode.data.dir</name>
  <value>/usr/local/hadoop/hadoop_work/hdfs/datanode</value>
</property>
<property>
  <name>dfs.namenode.checkpoint.dir</name>
  <value>/usr/local/hadoop/hadoop_work/hdfs/namesecondary</value>
</property>
<property>
  <name>dfs.block.size</name>
  <value>134217728</value>
</property>
<property>
  <name>dfs.client.use.datanode.hostname</name>
  <value>true</value>
</property>
<property>
  <name>dfs.datanode.socket.write.timeout</name>
  <value>2000000</value>
</property>
<property>
  <name>dfs.socket.timeout</name>
  <value>2000000</value>
</property>

<property>
  <name>dfs.datanode.use.datanode.hostname</name>
  <value>true</value>
  <description>Whether datanodes should use datanode hostnames when
    connecting to other datanodes for data transfer.
  </description>
</property>

<property>
  <name>dfs.namenode.rpc-bind-host</name>
  <value>0.0.0.0</value>
  <description>
    The actual address the RPC server will bind to. If this optional address is
    set, it overrides only the hostname portion of dfs.namenode.rpc-address.
    It can also be specified per name node or name service for HA/Federation.
    This is useful for making the name node listen on all interfaces by
    setting it to 0.0.0.0.
  </description>
</property>

<property>
  <name>dfs.namenode.servicerpc-bind-host</name>
  <value>0.0.0.0</value>
  <description>
    The actual address the service RPC server will bind to. If this optional address is
    set, it overrides only the hostname portion of dfs.namenode.servicerpc-address.
    It can also be specified per name node or name service for HA/Federation.
    This is useful for making the name node listen on all interfaces by
    setting it to 0.0.0.0.
  </description>
</property>

<property>
  <name>dfs.namenode.http-bind-host</name>
  <value>0.0.0.0</value>
  <description>
    The actual address the HTTP server will bind to. If this optional address
    is set, it overrides only the hostname portion of dfs.namenode.http-address.
    It can also be specified per name node or name service for HA/Federation.
    This is useful for making the name node HTTP server listen on all
    interfaces by setting it to 0.0.0.0.
  </description>
</property>

<property>
  <name>dfs.namenode.https-bind-host</name>
  <value>0.0.0.0</value>
  <description>
    The actual address the HTTPS server will bind to. If this optional address
    is set, it overrides only the hostname portion of dfs.namenode.https-address.
    It can also be specified per name node or name service for HA/Federation.
    This is useful for making the name node HTTPS server listen on all
    interfaces by setting it to 0.0.0.0.
  </description>
</property>