Hadoop Kerberos

Hadoop Kerberos is a security feature that provides authentication and authorization for Hadoop clusters. Kerberos is a network authentication protocol that allows nodes in a network to securely authenticate the identities of users or services over a non-secure network, like the internet.

In the context of Hadoop, Kerberos is used to secure various components of the Hadoop ecosystem, ensuring that only authorized users and services can access data and perform operations within the cluster. Here’s an overview of how Hadoop Kerberos works:

1. Authentication: Hadoop Kerberos provides strong user authentication. Users must obtain a valid Kerberos ticket from the Key Distribution Center (KDC) before they can interact with Hadoop services.

2. Principal and Keytab: In the context of Hadoop, each user or service that needs to interact with the Hadoop cluster is represented by a Kerberos principal. A principal is typically a combination of a username and a realm (e.g., user@REALM). To authenticate without entering a password interactively, users can use a keytab file, which contains a copy of their principal’s secret key.

3. Hadoop Configuration: Hadoop components, such as HDFS (Hadoop Distributed File System), YARN (Yet Another Resource Negotiator), and MapReduce, are configured to use Kerberos for authentication. This involves specifying the KDC’s hostname and realm in the Hadoop configuration files (core-site.xml, hdfs-site.xml, yarn-site.xml, etc.).

4. Ticket Renewal: Once a user obtains a Kerberos ticket, it has a limited lifetime. Hadoop services can be configured to periodically renew these tickets for long-running jobs.

5. Authorization: Hadoop also uses Kerberos for authorization. Access to Hadoop resources is controlled based on the Kerberos principal, which is associated with specific permissions and roles within the Hadoop ecosystem.