Proposal to support SOLR for short-term audit - remove support for database audit in the upcoming release ...

[Selvamohan Neethiraj <sn...@apache.org>]

As the size of audits are keep increasing, number of users are facing issues related to space and/or truncation of audit logs in the database. 
In the last ranger release,  Apache SOLR is set as the default choice for short-term audit, which provides data for reports in the ranger-admin UI and the user can set HDFS as the long-term audit destination.

In the next upcoming release, I am proposing that we move the users to move to SOLR for audit as default (if they are having DB audit) and remove support for database as audit storage, going forward. 

Please share your feedback here to find the best path for resolving this issue.

Thanks,
Selva-