(value: 5) 15 min period 15 min period Real heap usage is much higher than IHOP (Bad) 70 Mixed GC cycles in 15 min Too Frequently (Bad) GC few garbage for one mixed gc cycle (Bad) Young gen adaptivity(Good) 10% ○ Increase InitiatingHeapOccupancyPercent to 65 IHOP works as expected (Good) 6 Mixed GC cycles in 15 min(Better) Mixed GC reclaim more garbage(Good) Time in GC decrease(Good) [4.2%~6.7%] Age-1-Size is about 50 MB ~ 60MB ● Next Tuning ○ Set SurvivorRatio from 8 (default) to 4 5 Mixed GC cycles in 15 min(Better) (6 -> 5) Only ~3 mixed gc in the cycle take > 90ms (Better) Time in GC decrease(Better)

edMem Alleged to protect against a bizarre Linux issue -XX:-ResizePLAB Alleged to save some CPU cycles in between GC epochs Postgres Conference China 2016 中国用户大会 RegionServer硬件建议 • 服务器硬盘空间不大于6TB*RegionServer