Hadoop群集中的节点数

我正在尝试设置Hadoop多节点集群

当我启动集群时，这里是我在控制台中的响应

hduser@hadoop-master:/usr/local/hadoop$ /usr/local/hadoop/sbin/start-dfs.sh
Starting namenodes on [hadoop-master]
hadoop-master: starting namenode, logging to /usr/local/hadoop/logs/hadoop-hduser-namenode-hadoop-master.out
hadoop-master: starting datanode, logging to /usr/local/hadoop/logs/hadoop-hduser-datanode-hadoop-master.out
hadoop-child: starting datanode, logging to /usr/local/hadoop/logs/hadoop-hduser-datanode-hadoop-child.out
Starting secondary namenodes [0.0.0.0]
0.0.0.0: starting secondarynamenode, logging to /usr/local/hadoop/logs/hadoop-hduser-secondarynamenode-hadoop-master.out
hduser@hadoop-master:/usr/local/hadoop$ jps
21079 NameNode
21258 DataNode
21479 SecondaryNameNode
21600 Jps
hduser@hadoop-master:/usr/local/hadoop$ /usr/local/hadoop/sbin/start-yarn.sh
starting yarn daemons
starting resourcemanager, logging to /usr/local/hadoop/logs/yarn-hduser-resourcemanager-hadoop-master.out
hadoop-child: starting nodemanager, logging to /usr/local/hadoop/logs/yarn-hduser-nodemanager-hadoop-child.out
hadoop-master: starting nodemanager, logging to /usr/local/hadoop/logs/yarn-hduser-nodemanager-hadoop-master.out
hduser@hadoop-master:/usr/local/hadoop$ jps
21079 NameNode
21258 DataNode
22117 Jps
21815 NodeManager
21479 SecondaryNameNode
21658 ResourceManager

您可以看到一个datanode正在hadoop子机器中启动

现在，当我尝试获取所有节点信息时。我看不到显示的所有节点

hduser@hadoop-master:/usr/local/hadoop$ bin/hdfs dfsadmin -report
Configured Capacity: 21103243264 (19.65 GB)
Present Capacity: 17825124352 (16.60 GB)
DFS Remaining: 17821085696 (16.60 GB)
DFS Used: 4038656 (3.85 MB)
DFS Used%: 0.02%
Under replicated blocks: 0
Blocks with corrupt replicas: 0
Missing blocks: 0
Missing blocks (with replication factor 1): 0

-------------------------------------------------
Live datanodes (1):

Name: 127.0.0.1:50010 (localhost)
Hostname: localhost
Decommission Status : Normal
Configured Capacity: 21103243264 (19.65 GB)
DFS Used: 4038656 (3.85 MB)
Non DFS Used: 3278118912 (3.05 GB)
DFS Remaining: 17821085696 (16.60 GB)
DFS Used%: 0.02%
DFS Remaining%: 84.45%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Sun Feb 26 17:13:04 UTC 2017

我需要在这里查看主人和孩子的信息。我有一个主节点和一个子节点

********************修理*******

根据弗兰克的说法，这是如何修复的

编辑/etc/config文件并同时提供主IP地址和子IP地址

更改了下面的2行

127.0.0.1 localhost hadoop-master
961.118.98.183 hadoop-child

到（在两个节点中）

2.按以下顺序重新启动群集..应重新格式化datanode

format will remove only the meta, the datanode's data directories will still be using the old namenode's identity which wil cause the datanode to fail(so delete the directories).

Can you please this order.. 
1) stop the cluster 
2) rm -rf /path/to/datanode/data/dir (in both nodes) 
3) hadoop namenode -format
4) START cluste

---

设置多节点环境时，必须明确定义

namenode

和

resourcemanager

地址

将此属性添加到两个节点中的

core site.xml

<property>
  <name>fs.defaultFS</name>
  <value>hdfs://hadoop-master:8020</value>
</property>

确保在所有节点的

/etc/hosts

文件中完成了IP地址和主机名映射

---

注意：如果服务正在运行，请停止它们并在再次启动它们之前添加这些属性。

您的一个数据节点没有运行！当我在子节点中尝试jps命令时..它显示其正在运行。hduser@hadoop-child:/home/ubuntu$jps 3286 NodeManager 3134 DataNode 3429 jps在core-site.xml中为两个节点中的属性fs.defaultFS设置的值是什么？另外，当前报告的节点的主机名错误。

localhost

。我没有为fs.defaultFS提供任何值。我正在尝试执行此操作，谢谢。但是，当我运行dfsadmin报告时，仍然会收到相同的报告…只报告一个节点。另外，正如您前面提到的，主机名仍然是localhost，报告的datanode的名称为

localhost

？这是正确的。它与我上面显示的报告完全相同。您重新启动了整个集群？是的，这是正确的。我运行了stop-dfs.sh和stop-thread.sh命令并重新启动了

<property>
  <name>fs.defaultFS</name>
  <value>hdfs://hadoop-master:8020</value>
</property>

<property>
  <name>yarn.resourcemanager.hostname</name>
  <value>hadoop-master</value>
</property>