linux系统优化配置

# 2 millions system-wide
sysctl -w fs.file-max=2097152
sysctl -w fs.nr_open=2097152
echo 2097152 > /proc/sys/fs/nr_open

ulimit -n 1048576
ulimit -u 12000

/etc/sysctl.conf

持久化 ‘fs.file-max’ 设置到 /etc/sysctl.conf 文件:

fs.file-max = 1048576

/etc/systemd/system.conf 设置服务最大文件句柄数:

DefaultLimitNOFILE=1048576

/etc/security/limits.conf

/etc/security/limits.conf 持久化设置允许用户/进程打开文件句柄数:

*      soft   nofile      1048576
*      hard   nofile      1048576
*      soft   nproc       12000
*      hard   nproc       12000

TCP 协议栈网络参数

并发连接 backlog 设置:

sysctl -w net.core.somaxconn=32768
sysctl -w net.ipv4.tcp_max_syn_backlog=16384
sysctl -w net.core.netdev_max_backlog=16384

可用知名端口范围:

sysctl -w net.ipv4.ip_local_port_range='1000 65535'

TCP Socket 读写 Buffer 设置:

sysctl -w net.core.rmem_default=262144
sysctl -w net.core.wmem_default=262144
sysctl -w net.core.rmem_max=16777216
sysctl -w net.core.wmem_max=16777216
sysctl -w net.core.optmem_max=16777216

#sysctl -w net.ipv4.tcp_mem='16777216 16777216 16777216'
sysctl -w net.ipv4.tcp_rmem='1024 4096 16777216'
sysctl -w net.ipv4.tcp_wmem='1024 4096 16777216'

TCP 连接追踪设置:

sysctl -w net.nf_conntrack_max=1000000
sysctl -w net.netfilter.nf_conntrack_max=1000000
sysctl -w net.netfilter.nf_conntrack_tcp_timeout_time_wait=30

TIME-WAIT Socket 最大数量、回收与重用设置:

net.ipv4.tcp_max_tw_buckets=1048576

# 注意: 不建议开启該设置，NAT模式下可能引起连接RST
# net.ipv4.tcp_tw_recycle = 1
# net.ipv4.tcp_tw_reuse = 1

FIN-WAIT-2 Socket 超时设置:

net.ipv4.tcp_fin_timeout = 15