【系统参数优化 sysctl】
优化系统最大打开文件数限制：
$ diff /etc/sysctl.conf.old /etc/sysctl.conf
41,43c41,57
< fs.file-max=65535
< fs.file-max=65535
< fs.file-max=65535
---
> #fs.file-max=65535
> #fs.file-max=65535
> fs.file-max=70000 #增大系统最大允许的文件句柄数（超过65535）
> net.ipv4.tcp_max_tw_buckets = 6000 #以下这些都是优化网络行为
> net.ipv4.ip_local_port_range = 1024 65000
> net.ipv4.tcp_tw_recycle = 1
> net.ipv4.tcp_tw_reuse = 1
> net.ipv4.tcp_syncookies = 1
> net.core.somaxconn = 262144
> net.core.netdev_max_backlog = 262144
> net.ipv4.tcp_max_orphans = 262144
> net.ipv4.tcp_max_syn_backlog = 262144
> net.ipv4.tcp_synack_retries = 1
> net.ipv4.tcp_syn_retries = 1
> net.ipv4.tcp_fin_timeout = 30
> net.ipv4.tcp_keepalive_time = 1200
> net.ipv4.tcp_orphan_retries = 2
