Chapter 3. Administration

3.1. Logging In

While a cluster can be started and stopped using only the AWS Web Console, you will need to log in to the master node of your cluster through SSH to perform some administration tasks, like adding user accounts and uploading data sets to the HDFS.

If you are familiar with SSH, here are the details:

User: ubuntu (this account has sudo privileges)
Host: The Public Hostname associated with your master node on EC2
You must connect with the keypair you created and downloaded when you started the master instance. You cannot log in with a password.

The exact process for logging in depends on whether you are running a Unix-like operating system (e.g., Linux or Mac OS X) or Windows.

3.1.1. From Unix/Linux/OS X

Open a shell and issue this command:

$ ssh -i keypair ubuntu@ec2-public-hostname
The authenticity of host 'ec2-public-hostname' can't be established.
RSA key fingerprint is [...].
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'ec2-public-hostname' (RSA) to the list of known hosts.
ubuntu@ec2-public-hostname $

keypair is the filename of the keypair you created and downloaded when setting up the master instance. It should have the extension *.pem. ec2-public-hostname is that instance's Public Hostname.

You can log out at any time by typing the exit command.

3.1.2. From Windows

On Windows, you will need to install an SSH client such as PuTTY. Download the latest package and install.

First, we will need to take the keypair you created and downloaded when setting up the master instance and convert it to a format that PuTTY understands native

Open the program PuTTYgen.
In the menu, go to Conversions → Import Key
Choose the keypair file (with the extension *.pem) that you downloaded from AWS.
Set a password for the private key file in the Key Passphrase box.
Click the Save Private Key button in the main screen and save the new key. It should have a *.ppk extension.

Now we can log into the master instance using the main PuTTY program:

Open PuTTY. The program will start with a screen that lets you configure the connection.
In the Session category, enter the Public Hostname of your EC2 master node in the Host Name box.
In the Connection → SSH → Auth category, click Browse next to the Private Key for Authentication box and choose your private key file (the one ending in *.ppk).
Click Open to connect.
Enter ubuntu for the username.

You should now have a shell on your master node on EC2.