Did the GC cycle happen after the cp command? The memory will be reclaimed based on the requirement for the new coming objects. We do not explicitly clean any memory.. it is taken care by the JVM.

and yes ideally it should, the unreferenced objects are to be cleared during GC.

If this is not happening then there might me some memory leak issue.

We can run an inti script to collect heap dump of driver and executor then we can show the objects occupying most of the memory and then can act accordingly.