Spring Boot YARN doesn't run on Hadoop 2.8.0 client cannot access DataNode

问题

I'm trying to run Spring Boot YARN sample (https://spring.io/guides/gs/yarn-basic/ on Windows). In application.yml I changed fsUri and resourceManagerHost to point to my VM's host 192.168.... But when I'm trying to run application Exceprion appears:

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.

It means that DataNode isn't accessible from my host machine. For that reason I added to hdfs-site.xml

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

But it still throws that exception.

I've got Hadoop 2.8.0 running on my VM. Here's conf. files:

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>

回答1:

Your core-site.xml should point to Namenode address but currently its pointing to 0.0.0.0 which means all addresses on the local machine. This will create ambiguous result as each machine shall be treated as Namenode.

Namenode should be only one in a hadoop cluster.

Replacing the 0.0.0.0 with the Namenode's ip or hostname should resolve the issue you are facing.