Too much memory is required
So use mkswap to be ensure server work well
I Hate java,made more memory consumption
2G(1024*2048) is enough
watch ---
watch -n 1 free
tun on ---
swapoff -a
dd if=/dev/zero of=/swapfile bs=1024 count=2097152
mkswap /swapfile
swapon /swapfile
grep SwapTotal /proc/meminfo
tun off ---
swapoff /swapfile
rm /swapfile