This PR adds a new property druid.router.sql.enable which allows the
Router to handle SQL queries when set to true.
This change does not affect Avatica JDBC requests and they are still routed
by hashing the Connection ID.
To allow parsing of the request object as a SqlQuery (contained in module druid-sql),
some classes have been moved from druid-server to druid-services with
the same package name.
This change allows the selection of a specific broker service (or broker tier) by the Router.
The newly added ManualTieredBrokerSelectorStrategy works as follows:
Check for the parameter brokerService in the query context. If this is a valid broker service, use it.
Check if the field defaultManualBrokerService has been set in the strategy. If this is a valid broker service, use it.
Move on to the next strategy
* Druid user permissions apply in the console
* Update index.md
* noting user warning in console page; some minor shuffling
* noting user warning in console page; some minor shuffling 1
* touchups
* link checking fixes
* Updated per suggestions
Kashif Faraz
sthetland
Jonathan Wei
Chi Cao Minh
Gian Merlino