我在azure的hadoop中创建了一个多节点（1个主节点和3个从节点）集群，我想所有的设置都已经完成了，但是当我运行一个测试文件时，它遇到了与stackoverflow中其他节点类似的问题，我尝试了他们的解决方案，但是，这个问题仍然无法解决。谁能帮帮我吗？我已经在这个问题上困了几天了

org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /benchmarks/TestDFSIO/io_control/in_file_test_io_0 could only be replicated to 0 nodes instead of minReplication (=1).  There are 0 datanode(s) running and no node(s) are excluded in this operation.
    at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget4NewBlock(BlockManager.java:1797)
    at org.apache.hadoop.hdfs.server.namenode.FSDirWriteFileOp.chooseTargetForNewBlock(FSDirWriteFileOp.java:265)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:2559)
    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:846)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:510)
    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:503)
    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:989)
    at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:868)
    at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:814)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1886)
    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2603)

    at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1493)
    at org.apache.hadoop.ipc.Client.call(Client.java:1439)
    at org.apache.hadoop.ipc.Client.call(Client.java:1349)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:227)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:116)
    at com.sun.proxy.$Proxy10.addBlock(Unknown Source)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.addBlock(ClientNamenodeProtocolTranslatorPB.java:444)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:422)
    at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeMethod(RetryInvocationHandler.java:165)
    at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invoke(RetryInvocationHandler.java:157)
    at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeOnce(RetryInvocationHandler.java:95)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:359)
    at com.sun.proxy.$Proxy11.addBlock(Unknown Source)
    at org.apache.hadoop.hdfs.DataStreamer.locateFollowingBlock(DataStreamer.java:1845)
    at org.apache.hadoop.hdfs.DataStreamer.nextBlockOutputStream(DataStreamer.java:1645)
    at org.apache.hadoop.hdfs.DataStreamer.run(DataStreamer.java:710)
org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /benchmarks/TestDFSIO/io_control/in_file_test_io_0 could only be replicated to 0 nodes instead of minReplication (=1).  There are 0 datanode(s) running and no node(s) are excluded in this operation.
    at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget4NewBlock(BlockManager.java:1797)
    at org.apache.hadoop.hdfs.server.namenode.FSDirWriteFileOp.chooseTargetForNewBlock(FSDirWriteFileOp.java:265)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:2559)
    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:846)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:510)
    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:503)
    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:989)
    at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:868)
    at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:814)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1886)
    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2603)

    at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1493)
    at org.apache.hadoop.ipc.Client.call(Client.java:1439)
    at org.apache.hadoop.ipc.Client.call(Client.java:1349)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:227)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:116)
    at com.sun.proxy.$Proxy10.addBlock(Unknown Source)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.addBlock(ClientNamenodeProtocolTranslatorPB.java:444)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:422)
    at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeMethod(RetryInvocationHandler.java:165)
    at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invoke(RetryInvocationHandler.java:157)
    at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeOnce(RetryInvocationHandler.java:95)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:359)
    at com.sun.proxy.$Proxy11.addBlock(Unknown Source)
    at org.apache.hadoop.hdfs.DataStreamer.locateFollowingBlock(DataStreamer.java:1845)
    at org.apache.hadoop.hdfs.DataStreamer.nextBlockOutputStream(DataStreamer.java:1645)
    at org.apache.hadoop.hdfs.DataStreamer.run(DataStreamer.java:710)

2018-04-13 01:25:24,359 WARN org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager: Unresolved datanode registration: hostname cannot be resolved (ip=10.0.0.7, hostname=10.0.0.7)
    2018-04-13 01:25:24,359 INFO org.apache.hadoop.ipc.Server: IPC Server handler 2 on 9000, call Call#3 Retry#0 org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol.registerDatanode from 10.0.0.7:59340

我检查了hadoop-hduser-namenode-master.log，发现了一些错误，似乎damenode无法连接namenode。

org.apache.hadoop.hdfs.server.protocol.DisallowedDatanodeException: Datanode denied communication with namenode because hostname cannot be resolved (ip=10.0.0.7, hostname=10.0.0.7): 
DatanodeRegistration(0.0.0.0:50010, datanodeUuid=5b728ca4-01d0-4540-b216-e31c01024b49, infoPort=50075, infoSecurePort=0, ipcPort=50020, storageInfo=lv=-57;cid=CID-e37e460a-966c-4067-8104-393b2c008d4a;nsid=1665807189;c=1523582587978)

但是我已经将所有从机的所有私钥添加到master，并且修改了/etc/hostname/etc/hosts，我还修改了master中的从机（slave1、slave2、slave3）和主机（master）文件。

# 127.0.0.1 localhost

master 10.0.0.4
slave1 10.0.0.5
slave2 10.0.0.6
slave3 10.0.0.7

# The following lines are desirable for IPv6 capable hosts

::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

我的核心站点.xml

core-site.xml
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://master:9000</value>
</property>
</configuration>

yarn-site.xml文件

<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.resourcemanager.resource-tracker.address</name>
<value>master:8025</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address</name>
<value>master:8030</value>
</property>
<property>

hdfs-site.xml（主节点使用namenode，从节点使用datanode）

<configuration>
<property>
<name>dfs.replication</name>
<value>3</value>
</property>
<property>
<name>dfs.namenode.name.dir</name>
<value>file:/usr/local/hadoop/hadoop_data/hdfs/namenode</value>
</property>
</configuration>

mapred-site.xml文件

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

另外，我已经查过了

Filesystem      Size  Used Avail Use% Mounted on
udev            944M     0  944M   0% /dev
tmpfs           191M  3.1M  188M   2% /run
/dev/sda1        30G  2.8G   27G  10% /
tmpfs           954M     0  954M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           954M     0  954M   0% /sys/fs/cgroup
/dev/sdb1       3.9G  8.0M  3.7G   1% /mnt
tmpfs           191M     0  191M   0% /run/user/1000

最后，我使用jps检查每个节点（当start all.sh时）：
奴隶2

7175 Jps

主人

11961 Jps

它们是不正常的。我该怎么办？