PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
635743 mongod 20 0 252g 251g 5880 S 0.3 69.5 4668:15 mongod
mongod process keeps using huge amount of memory even though client threads that do some processing are done hours ago. Yet mongo keeps using RAM memory of about 70%. Any ideas why this is happenning ?