"Encapsulate your data structures - this is best practice for coding, for maintenance, and performance (you make the underlying implementation more efficient without having to change anything in the rest of the application)."
"The four refinement zones (white green yellow red) affect how much work G1 needs to do to update queued pointer changes into the remembered sets. In the white zone, nothing is done (it's drained at the beginning of a GC); in the green zone -XX:G1ConcRefinementGreenZone refinement threads are activated to reduce the queue back to the white zone; in the yellow zone -XX:G1ConcRefinementYellowZone all refinement threads are fully active to reduce the queue; in the red zone -XX:G1ConcRefinementRedZone the application has to update the remembered sets on each pointer change which slows down the application until the queue is back into the yellow zone."
