Apache Druid

<@U03M03LA544> has been doing a bunch of looking into this

you can read about the adventure on <https://github.com/apache/druid/pull/12032>

i think where things are at now is there are some funny test issues related to memory pooling

<https://github.com/apache/druid/pull/12032#issuecomment-1251607235>

There’s a bunch of new MSQ code that needs to be ported to Netty 4 too :)

Mostly the new mock clients for testing. 

&gt; MSQ code that needs to be ported to Netty 4
if you point me in the right direction I can get started

MSQTestBase is the class where all the stuff happens.

```/**
 * Base test runner for running MSQ unit tests. It sets up multi stage query execution environment
 * and populates data for the datasources. The runner does not go via the HTTP layer for communication between the
 * various MSQ processes.
 *
 * Controller -&gt; Coordinator (Coordinator is mocked)
 *
 * In the Ut's we go from:
 * {@link MSQTaskQueryMaker} -&gt; {@link MSQTestOverlordServiceClient} -&gt; {@link Controller}
 *
 *
 * Controller -&gt; Worker communication happens in {@link MSQTestControllerContext}
 *
 * Worker -&gt; Controller communication happens in {@link MSQTestControllerClient}
 *
 * Controller -&gt; Overlord communication happens in {@link MSQTestTaskActionClient}```


I updated <https://github.com/apache/druid/pull/12032> so all the code compiles and unit tests pass.

still seeing various new failures, and some OOM issues in some integration tests

<@U0315MQKEHK> are you still looking into helping out with this?

Just saw this thread. <@U03M03LA544> What kind of help do you need ?