Spring Boot YARN未在Hadoop 2.8.0客户端上运行无法访问DataNode

Question

我正在尝试运行Spring Boot YARN示例（在Windows上为https://spring.io/guides/gs/yarn-
basic/
）。在application.yml我更改fsUri并resourceManagerHost指向我的VM的主机192.168...。但是，当我尝试运行应用程序时，Exceprion出现了：

DFSClient: Exception in createBlockOutputStream
java.net.ConnectException: Connection timed out: no further information
    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
    at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
    at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
    at org.apache.hadoop.hdfs.DFSOutputStream.createSocketForPipeline(DFSOutputStream.java:1508)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.createBlockOutputStream(DFSOutputStream.java:1284)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1237)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:449)
[2017-05-27 19:59:49.570] boot - 7728  INFO [Thread-5] --- DFSClient: Abandoning BP-646365587-10.0.2.15-1495898351938:blk_1073741830_1006
[2017-05-27 19:59:49.602] boot - 7728  INFO [Thread-5] --- DFSClient: Excluding datanode DatanodeInfoWithStorage[10.0.2.15:50010,DS-f909ec7a-8374-4cdd-9cfc-0e778810d98c,DISK]
[2017-05-27 19:59:49.647] boot - 7728  WARN [Thread-5] --- DFSClient: DataStreamer Exception
org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /app/gs-yarn-basic/gs-yarn-basic-container-0.1.0.jar could only be replicated to 0 nodes instead of minReplication (=1).  There are 1 datanode(s) running and 1 node(s) are excluded in this operation.

这意味着无法从我的主机访问DataNode。因此，我将其添加到hdfs-site.xml中

<property>
  <name>dfs.client.use.datanode.hostname</name>
  <value>true</value>
  <description>Whether clients should use datanode hostnames when
    connecting to datanodes.
  </description>
</property>

但是它仍然抛出该异常。

我的VM上正在运行Hadoop 2.8.0。这是conf。文件：

core-site.xml

<configuration>
   <property>
       <name>fs.defaultFS</name>
       <value>hdfs://0.0.0.0:9000</value>
   </property>

</configuration>

hdfs-site.xml

    <configuration>
       <property>
           <name>dfs.replication</name>
           <value>1</value>
       </property>
       <property>
           <name>dfs.namenode.name.dir</name>
           <value>/usr/local/hadoop/hadoop-2.8.0/data/namenode</value>
       </property>

       <property>
           <name>dfs.datanode.data.dir</name>
           <value>/usr/local/hadoop/hadoop-2.8.0/data/datanode</value>
       </property>

        <property>
            <name>dfs.permissions.enabled</name>
            <value>false</value>
        </property>

        <property>
           <name>dfs.client.use.datanode.hostname</name>
           <value>true</value>
           <description>Whether clients should use datanode hostnames when
              connecting to datanodes.
           </description>
        </property>
   </configuration>

mapred-site.xml

<configuration>    
   <property>
       <name>mapreduce.framework.name</name>
       <value>yarn</value>
   </property>
</configuration>

yarn-site.xml

<configuration>
    <property>
       <name>yarn.nodemanager.aux-services</name>
       <value>mapreduce_shuffle</value>
    </property>
    <property>
       <name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
       <value>org.apache.hadoop.mapred.ShuffleHandler</value>
    </property>
    <property>
        <name>yarn.scheduler.maximum-allocation-mb</name>
        <value>8192</value>
    </property>
        <property>
        <name>yarn.nodemanager.resource.memory-mb</name>
        <value>8192</value>
    </property>
    <property>
        <name>yarn.nodemanager.disk-health-checker.max-disk-utilization-per-
           disk-percentage</name>
        <value>99</value>
    </property>    
</configuration>

Answer 1

您core- site.xml应该指向Namenode地址，但当前指向的0.0.0.0是本地计算机上的所有地址。这将导致模棱两可的结果，因为每台机器都应视为Namenode。

Namenode 只能是hadoop集群中的一个。

更换0.0.0.0用Namenode的ip还是hostname应该可以解决你所面临的问题。