Pre-requisite for establishing password less sessions between nodes

[#1]

Hi,

One of prerequisites for establishing a hadoop cluster is two create passwordless sessions between nodes.

I am aware of how to generate pass-wordless session between node1 and node2 by creating

#ssh-keygen

and then coping the contents to destination like below

#cat .ssh/id_rsa.pub | ssh root@192.168.192.18 'cat >>
.ssh/authorized_keys'

my question is that shoul I do this between each 2 nodes once or two times.

for example once from node1 to node2 and then again from node2 to node1?

Thanks.

[#2]

@Lucky_Luke,

This is required only from one node. You should be able to do passwordless ssh from ambari server node to all the other nodes.

# cat .ssh/id_rsa.pub | ssh root@{ambari-ip} 'cat >> .ssh/authorized_keys'