I would also recommend following the below two guides:
https://forums.spongepowered.org/t/optimized-startup-flags-for-consistent-garbage-collection/13239
https://docs.google.com/document/d/1LJ5VodluXPU_rse0ulfZNg36yaclWvglrNxrpk_OyOM/edit?usp=drivesdk