Dataset service has 10 workers and 30 executors
AppFabric has 10 workers and 20 executors
Scheduler has 15 constraint checker threads
Don't the unit tests run with enough resources to support these number of threads?
they might. But they are unit tests and not integration tests. A unit test should not have to spin up a full-fledged system. It also makes debugging and reading logs harder if there are hundreds of thread trace-logging.