Deleting all documents in a Solr collection does not delete the collection or its
    configuration files. It only deletes the index. This can be useful for rapid prototyping of
    configuration changes in test environments.
    
    If you have enabled Ranger for authorization, you must have
        Solr Admin permission to be able to delete documents in a
      collection.- If you are using Kerberos, 
kinit as a user with permission to delete the
          collection:  
        
          kinit solradmin@[***EXAMPLE.COM***]
          Replace [***EXAMPLE.COM***] with your Kerberos realm name.
          - On a host running Solr Server, make sure that the 
SOLR_ZK_ENSEMBLE environment
          variable is set in /etc/solr/conf/solr-env.sh. For example:  
        
          $ cat /etc/solr/conf/solr-env.sh
export SOLR_ZK_ENSEMBLE=zk01.example.com:2181,zk02.example.com:2181,zk03.example.com:2181/solr
          If you are using Cloudera Manager, this is automatically set on hosts with a
              Solr Server or Gateway role.
          - Delete the documents: 
        
          solrctl collection --deletedocs logs