Configuring Kerberos Authentication for Hadoop: A Step-by-Step Guide with Example

Kerberos is a network authentication protocol that provides secure authentication over a non-secure network. In Hadoop, Kerberos is used to authenticate users and services.

Step 1: Install Kerberos The first step is to install Kerberos on all nodes in the Hadoop cluster. The Kerberos server (KDC) can be installed on a separate node, or on one of the nodes in the Hadoop cluster.

Step 2: Create a Kerberos Realm The next step is to create a Kerberos realm. This can be done using the kadmin command on the KDC. A realm is a domain that is managed by a Kerberos KDC. In this example, we'll use the realm EXAMPLE.COM.

Step 3: Create Kerberos Principals Next, we need to create Kerberos principals for the Hadoop services and users. A principal is a unique identifier for a user or service in a Kerberos realm. In this example, we'll create a principal for the Hadoop superuser, hdfs user, and the datanode service.

Step 4: Configure Hadoop to use Kerberos Now that we have created the necessary Kerberos principals, we need to configure Hadoop to use Kerberos for authentication. This can be done by modifying the core-site.xml, hdfs-site.xml, and mapred-site.xml configuration files.

Step 5: Test the Kerberos Authentication Finally, we need to test the Kerberos authentication. This can be done by running a simple Hadoop command, such as listing the contents of a directory. If Kerberos authentication is configured correctly, you should be prompted for a Kerberos ticket when running the command

 Example: Here's an example of how to configure Kerberos authentication for Hadoop:

  1. Install Kerberos on all nodes in the Hadoop cluster.
  2. Create a Kerberos realm using the kadmin command on the KDC:
css
kadmin.local -q "addprinc admin/admin@EXAMPLE.COM"
  1. Create Kerberos principals for the Hadoop services and users:
lua
kadmin.local -q "addprinc hdfs/example.com@EXAMPLE.COM" kadmin.local -q "addprinc datanode/example.com@EXAMPLE.COM"
  1. Modify the core-site.xml, hdfs-site.xml, and mapred-site.xml configuration files to use Kerberos authentication:
php
<property> <name>hadoop.security.authentication</name> <value>kerberos</value> </property> <property> <name>hadoop.security.authorization</name> <value>true</value> </property> <property> <name>hadoop.security.auth_to_local</name> <value> RULE:[2:$1@$0](.*@EXAMPLE.COM)s/@.*// DEFAULT </value> </property> <property> <name>dfs.namenode.kerberos.principal</name> <value>hdfs/_HOST@EXAMPLE.COM</value> </property> <property> <name>dfs.datanode.kerberos.principal</name> <value>datanode/_HOST@EXAMPLE.COM</value> </property> <property> <name>mapreduce.jobtracker.kerberos.principal</name> <value>mapred/_HOST@EXAMPLE.COM</value> </property>
  1. Test the Kerberos authentication by running a simple Hadoop command:
bash
hadoop fs -ls /

If Kerberos authentication is configured correctly, you should be prompted for a Kerberos ticket when running the command.

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