配置ssh免密登录
1、cd ~
cd .ssh
输入ssh-keygen -t rsa 敲三次回车
[root@cdh-hadoop3 .ssh]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:DsVHiCkKQE+kYrcT/MqGSkgduANEs+YFhRBUR0z7vtQ root@cdh-hadoop3
The key's randomart image is:
+---[RSA 2048]----+
|XO==++ o .. |
|o.X o.+... |
|oB O o o . |
|* * = .. . |
| = + ...S |
|o + o .o. |
|.o + o.E |
|o . . . |
|. . |
+----[SHA256]-----+生成两个文件
[root@cdh-hadoop3 .ssh]# ls -a
. .. id_rsa id_rsa.pub2、将公钥拷贝到集群的所有节点中
[root@cdh-hadoop1 ~]# ssh-copy-id cdh-hadoop1
[root@cdh-hadoop1 ~]# ssh-copy-id cdh-hadoop2
[root@cdh-hadoop1 ~]# ssh-copy-id cdh-hadoop3
3.只需要将cdh-hadoop1也就是集群中的master节点上的公钥拷贝到其他所有节点即可。集群的通信只需要master节点能连接所有worker节点即可。