https://github.com/apache/incubator-druid/pull/6798 Please check it out Nikita
On Sat, Dec 29, 2018 at 11:59 PM Nikita Dolgov <java.saas.had...@gmail.com> wrote: > I was experimenting with a Druid extension prototype and encountered some > difficulties. The experiment is to build something like > https://github.com/apache/incubator-druid/issues/3891 with gRPC. > > (1) Guava version > > Druid relies on 16.0.1 which is a very old version (~4 years). My only > guess is another transitive dependency (Hadoop?) requires it. The earliest > version used by gRPC from three years ago was 19.0. So my first question is > if there are any plans for upgrading Guava any time soon. > > (2) Druid thread model for query execution > > I played a little with calling > org.apache.druid.server.QueryLifecycleFactory::runSimple under debugger. > The stack trace was rather deep to reverse engineer easily so I'd like to > ask directly instead. Would it be possible to briefly explain how many > threads (and from which thread pool) it takes on a broker node to process, > say, a GroupBy query. > > At the very least I'd like to know if calling > QueryLifecycleFactory::runSimple on a thread from some "query processing > pool" is better than doing it on the IO thread that received the query. > > (3) Yielder > > Is it safe to assume that QueryLifecycleFactory::runSimple always returns > a Yielder<org.apache.druid.data.input.Row> ? QueryLifecycle omits generic > types rather liberally when dealing with Sequence instances. > > (4) Calcite integration > > Presumably Avatica has an option of using protobuf encoding for the > returned results. Is it true that Druid cannot use it? > On a related note, any chance there was something written down about > org.apache.druid.sql.calcite ? > > Thank you > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@druid.apache.org > For additional commands, e-mail: dev-h...@druid.apache.org > >
