Apache Sentry Guide
The Sentry service is an RPC server that stores authorization metadata in an underlying relational database and provides RPC interfaces to retrieve and manipulate privileges. It supports secure access to services using Kerberos. The service serves authorization metadata from the database backed storage; it does not handle actual privilege validation. The Hive, Impala, and Solr services are clients of this service and will enforce Sentry privileges when they are configured to use Sentry.