hadoop 集羣子節點不啓動 spark-slave1: ssh: Could not resolve hostname spark-slave1: Name or service not know

報錯信息：

./start-all.sh 
This script is Deprecated. Instead use start-dfs.sh and start-yarn.sh
Starting namenodes on [master]
master: starting namenode, logging to /usr/local/hadoop/logs/hadoop-root-namenode-master.out
spark-slave1: ssh: Could not resolve hostname spark-slave1: Name or service not known
spark-slave2: ssh: Could not resolve hostname spark-slave2: Name or service not known
Starting secondary namenodes [0.0.0.0]
0.0.0.0: starting secondarynamenode, logging to /usr/local/hadoop/logs/hadoop-root-secondarynamenode-master.out
starting yarn daemons
starting resourcemanager, logging to /usr/local/hadoop/logs/yarn--resourcemanager-master.out
spark-slave2: ssh: Could not resolve hostname spark-slave2: Name or service not known
spark-slave1: ssh: Could not resolve hostname spark-slave1: Name or service not known

分析：報錯信息大概意思是沒法解析spark-slave1和spark-slave2主機名，我子節點的主機名明明是node1和node2，找了好久終於找到了問題所在

在slaves文件中

vim /usr/local/hadoop/etc/hadoop/slaves 

spark-slave1
spark-slave2

設置了默認的子節點主機名，改成本身的子節點便可

vim /usr/local/hadoop/etc/hadoop/slaves 

node1
node2

而後重啓hadoop

./stop-all.sh //關閉
./start-all.sh //啓動

而後發現就不報錯了，子節點啓動成功

@master:/usr/local/hadoop/sbin# jps
5698 ResourceManager
6403 Jps
5547 SecondaryNameNode
5358 NameNode

@node1:~# jps
885 Jps
744 NodeManager
681 DataNode

@node2:~# jps
914 Jps
773 NodeManager
710 DataNode

總結：hadoop下的slaves文件官方解釋爲：集羣裏的一臺機器被指定爲 NameNode，另外一臺不一樣的機器被指定爲JobTracker。這些機器是masters，餘下的機器即做爲DataNode也做爲TaskTracker，這些機器是slaves，在slaves文件中列出全部slave的主機名或者IP地址，一行一個。  意思就是子節點主機名或ip，固然也能夠設置爲172之類的ip地址。