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<!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN"
          "http://forrest.apache.org/dtd/document-v20.dtd">


<document>

  <header>
    <title> 
      Authentication for Hadoop HTTP web-consoles
    </title>
  </header>

  <body>
    <section>
      <title> Introduction </title>
      <p>
        This document describes how to configure Hadoop HTTP web-consoles to require user
        authentication. 
      </p>
      <p>
        By default Hadoop HTTP web-consoles (JobTracker, NameNode, TaskTrackers and DataNodes) allow 
        access without any form of authentication. 
      </p>
      <p>
        Similarly to Hadoop RPC, Hadoop HTTP web-consoles can be configured to require Kerberos 
        authentication using HTTP SPNEGO protocol (supported by browsers like Firefox and Internet
        Explorer).        
      </p>
      <p>
        In addition, Hadoop HTTP web-consoles support the equivalent of Hadoop's Pseudo/Simple
        authentication. If this option is enabled, user must specify their user name in the first
        browser interaction using the <code>user.name</code> query string parameter. For example:
        <code>http://localhost:50030/jobtracker.jsp?user.name=babu</code>.
      </p>
      <p>
        If a custom authentication mechanism is required for the HTTP web-consoles, it is possible 
        to implement a plugin to support the alternate authentication mechanism (refer to 
        Hadoop Alfredo for details on writing an <code>AuthenticatorHandler</code>).
      </p>
      <p>       
        The next section describes how to configure Hadoop HTTP web-consoles to require user 
        authentication.
      </p>
    </section>

    <section> 
      <title> Configuration </title>

      <p>
        The following properties should be in the <code>core-site.xml</code> of all the nodes
        in the cluster.
      </p>

      <p><code>hadoop.http.filter.initializers</code>: add to this property the 
      <code>org.apache.hadoop.security.AuthenticationFilterInitializer</code> initializer class.
      </p>
      
      <p><code>hadoop.http.authentication.type</code>: Defines authentication used for the HTTP 
      web-consoles. The supported values are: <code>simple | kerberos | 
      #AUTHENTICATION_HANDLER_CLASSNAME#</code>. The dfeault value is <code>simple</code>.
      </p>

      <p><code>hadoop.http.authentication.token.validity</code>: Indicates how long (in seconds) 
      an authentication token is valid before it has to be renewed. The default value is 
      <code>36000</code>.
      </p>

      <p><code>hadoop.http.authentication.signature.secret.file</code>: The signature secret
      file for signing the authentication tokens. If not set a random secret is generated at
      startup time. The same secret should be used for all nodes in the cluster, JobTracker,
      NameNode, DataNode and TastTracker. The default value is
      <code>${user.home}/hadoop-http-auth-signature-secret</code>.
      IMPORTANT: This file should be readable only by the Unix user running the daemons.
      </p>
        
      <p><code>hadoop.http.authentication.cookie.domain</code>: The domain to use for the HTTP 
      cookie that stores the authentication token. In order to authentiation to work 
      correctly across all nodes in the cluster the domain must be correctly set.
      There is no default value, the HTTP cookie will not have a domain working only
      with the hostname issuing the HTTP cookie.
      </p>

      <p>
      IMPORTANT: when using IP addresses, browsers ignore cookies with domain settings.
      For this setting to work properly all nodes in the cluster must be configured
      to generate URLs with hostname.domain names on it.
      </p>

      <p><code>hadoop.http.authentication.simple.anonymous.allowed</code>: Indicates if anonymous 
      requests are allowed when using 'simple' authentication. The default value is 
      <code>true</code>
      </p>

      <p><code>hadoop.http.authentication.kerberos.principal</code>: Indicates the Kerberos 
      principal to be used for HTTP endpoint when using 'kerberos' authentication.
      The principal short name must be <code>HTTP</code> per Kerberos HTTP SPNEGO specification.
      The default value is <code>HTTP/localhost@$LOCALHOST</code>.
      </p>

      <p><code>hadoop.http.authentication.kerberos.keytab</code>: Location of the keytab file 
      with the credentials for the Kerberos principal used for the HTTP endpoint. 
      The default value is <code>${user.home}/hadoop.keytab</code>.i
      </p>

    </section>

  </body>
</document>

