Blocker Description
On a test cluster, every time I run a spark SQL query against a table, each of my spark worker tasks end up with another ~500 netty worker threads created. It seems like each Spark partition/task is creating its own KuduClient which then creates a bunch of worker threads and never cleans them up.
I'm calling this a blocker since after ~20 queries or so, the machines woudl run out of threads and crash.