SSH is the de facto standard protocol for secure data connection and remote command execution. Proper configuration of SSH is required for Hadoop installation. In this section, we are going to learn how to configure SSH on the cluster nodes. Specifically, we are discussing how to configure SSH for a passwordless login to a remote machine.
Start up the SSHD service on all the cluster nodes (both the slave nodes and the master node) with the following command:
sudo service sshd start
Make the service survive system reboot with the command:
sudo chkconfig sshd on
Verify whether sshd
works properly with the command from the master node:
ssh hduser@slave1
If it is the first time of logging into to the host, we will get a message similar to the following:
The authenticity of host 'hdslave.host(10.0.0.1)' can't be established. RSA key fingerprint is 7c:e0:61:3b:b6:70:07:ab:65:f9:bf:2d:90:77:1b:57. Are you sure you want to continue connecting (yes/no)?
We need to type...