linux 内核优化

1、修改ulimit

vi /etc/security/limits.conf

增加

* soft nofile 65535

* hard nofile 65535

* - nofile 65535

修改 linux 内核文件 sysctl  -P 报错
error: "net.bridge.bridge-nf-call-ip6tables" is an unknown key
error: "net.bridge.bridge-nf-call-iptables" is an unknown key
error: "net.bridge.bridge-nf-call-arptables" is an unknown key 
解决方法如下：
modprobe bridge
lsmod|grep bridge

2、修改内核参数

vi /etc/sysctl.conf

增加

net.ipv4.tcp_fin_timeout = 30

net.ipv4.tcp_keepalive_time = 1200

net.ipv4.tcp_syncookies = 1

net.ipv4.tcp_tw_reuse = 1

net.ipv4.tcp_tw_recycle = 1

net.ipv4.ip_local_port_range = 1024 65000

net.ipv4.tcp_max_syn_backlog = 8192

net.ipv4.tcp_max_tw_buckets = 5000

sysctl -p 生效

3、修改hostname

vi /etc/hosts