No longer support Kerberos for Solr on HDFS

solr/solr-ref-guide/modules/deployment-guide/pages/solr-on-hdfs.adoc

@@ -210,41 +210,6 @@ NRTCachingDirectory max cache size.
 +
 Pass the location of HDFS client configuration files - needed for HDFS HA for example.
 
-=== Kerberos Authentication Settings
-
-Hadoop can be configured to use the Kerberos protocol to verify user identity when trying to access core services like HDFS.
-If your HDFS directories are protected using Kerberos, then you need to configure Solr's HdfsDirectoryFactory to authenticate using Kerberos in order to read and write to HDFS.
-To enable Kerberos authentication from Solr, you need to set the following parameters:
-
-`solr.hdfs.security.kerberos.enabled`::
-+
-[%autowidth,frame=none]
-|===
-|Optional |Default: `false`
-|===
-+
-Set to `true` to enable Kerberos authentication.
-
-`solr.hdfs.security.kerberos.keytabfile`::
-+
-[%autowidth,frame=none]
-|===
-s|Required |Default: none
-|===
-+
-A keytab file contains pairs of Kerberos principals and encrypted keys which allows for password-less authentication when Solr attempts to authenticate with secure Hadoop.
-+
-This file will need to be present on all Solr servers at the same path provided in this parameter.
-
-`solr.hdfs.security.kerberos.principal`::
-+
-[%autowidth,frame=none]
-|===
-s|Required |Default: none
-|===
-+
-The Kerberos principal that Solr should use to authenticate to secure Hadoop; the format of a typical Kerberos V5 principal is: `primary/instance@realm`.
-
 == Update Log settings
 When using HDFS to store Solr indexes, it is recommended to also store the transaction logs on HDFS. This can be done by using the `solr.HdfsUpdateLog` update log hander class.
 The solrconfig.xml is often used to define an update log handler class name either using a variable reference or direct specification, for example: