In the process of building the Hadoop platform, public and private keys have been generated. But the following appears when starting start-dfs.sh:
[root@master sbin]# start-dfs.sh
Starting namenodes on [master]
The authenticity of host 'master (192.168.80.5)' can't be established.
ECDSA key fingerprint is SHA256:kwMDpIlPjgPyTTQLN3Tg2pCFoXTiWmijpXICUN7vYb0.
ECDSA key fingerprint is MD5:71:57:00:3f:be:cc:90:61:00:bb:43:6e:bc:a0:80:ad.
Are you sure you want to continue connecting (yes/no)? yes
master: Warning: Permanently added 'master,192.168.80.5' (ECDSA) to the list of known hosts.
master: starting namenode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-namenode-master.out
master: starting datanode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-datanode-master.out
slave2: starting datanode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-datanode-slave2.out
slave1: starting datanode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-datanode-slave1.out
Starting secondary namenodes [0.0.0.0]
The authenticity of host '0.0.0.0 (0.0.0.0)' can't be established.
ECDSA key fingerprint is SHA256:kwMDpIlPjgPyTTQLN3Tg2pCFoXTiWmijpXICUN7vYb0.
ECDSA key fingerprint is MD5:71:57:00:3f:be:cc:90:61:00:bb:43:6e:bc:a0:80:ad.
Are you sure you want to continue connecting (yes/no)? yes
0.0.0.0: Warning: Permanently added '0.0.0.0' (ECDSA) to the list of known hosts.
0.0.0.0: starting secondarynamenode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-secondarynamenode-master.out
Solution:
Modify the configuration of the /etc/ssh/ssh_config file, and this problem will no longer occur in the future.
#打开文件
vi /etc/ssh/ssh_config
#在最后面添加如下语句即可
StrictHostKeyChecking no
UserKnownHostsFile /dev/null
after modification:
[root@master sbin]# start-dfs.sh
Starting namenodes on [master]
master: Warning: Permanently added 'master,192.168.80.5' (ECDSA) to the list of known hosts.
master: starting namenode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-namenode-master.out
slave2: Warning: Permanently added 'slave2,192.168.80.7' (ECDSA) to the list of known hosts.
slave1: Warning: Permanently added 'slave1,192.168.80.6' (ECDSA) to the list of known hosts.
master: Warning: Permanently added 'master,192.168.80.5' (ECDSA) to the list of known hosts.
slave1: starting datanode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-datanode-slave1.out
slave2: starting datanode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-datanode-slave2.out
master: starting datanode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-datanode-master.out
Starting secondary namenodes [0.0.0.0]
0.0.0.0: Warning: Permanently added '0.0.0.0' (ECDSA) to the list of known hosts.
0.0.0.0: starting secondarynamenode, logging to /usr/hadoop/hadoop-2.10.0/logs/hadoop-root-secondarynamenode-master.out