Turn off the swap
For best performance on a dedicated Oracle NoSQL Database server machine, turn off the swap on the machine. Oracle NoSQL Database processes are careful in their management of the memory they use to ensure that they do not exceed the RAM available on the machine.
The performance gains come from two sources:
-
The I/O overhead due to swap is eliminated. This is especially important if the disk normally used for swap also holds the store's log files used to persist data.
-
Reduces the CPU overhead associated with kswapd.
To turn off the swap, do not mount any swap partitions at boot time. You do this by eliminating all swap related mount entries from /etc/fstab
. These are all the rows with the entry "swap" in their mount point (column 2) and file system type (column 3) entries.
You can verify that no swap space is being used by running the free
command. Do this after the /etc/fstab
has been modified and the machine has been rebooted:
-bash-4.1$ free -m
total used free shared buffers cached
Mem: 72695 72493 202 0 289 2390
-/+ buffers/cache: 69813 2882
Swap: 0 0 0
The Swap/total
cell in the above table should read 0
.