系统内核如下： centos6.8 [root@localhost ~]# uname -a Linux localhost.localdomain 2.6.32-642.el6.x86_64 #1 SMP Tue May 10 17:27:01 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
服务器硬盘配置： 2颗cpu，单核12核心，开启超线程 cpu型号：Intel(R) Xeon(R) cpu E5-2690 v3 @ 2.60GHz （41500元一台机器） 共计48线程的逻辑cpu
优化如下：
[root@localhost ~]# cat /etc/sysctl.conf net.ipv4.ip_forward= 0
kernel.sysrq = 0 kernel.msgmnb = 65536 kernel.msgmax = 65536 kernel.shmmax = 68719476736 kernel.shmall = 4294967296 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_synack_retries = 2 net.ipv4.tcp_syn_retries = 2 vm.overcommit_memory = 1 net.ipv4.tcp_max_syn_backlog = 1638400 net.core.somaxconn = 1638400 net.core.netdev_max_backlog = 20000 net.ipv4.tcp_max_tw_buckets = 1800000 net.ipv4.conf.all.send_redirects = 0 net.ipv4.conf.all.accept_redirects = 0 net.ipv4.tcp_fin_timeout = 10 net.ipv4.tcp_keepalive_time = 90 net.ipv4.ip_local_port_range = 1024 65000 net.ipv4.tcp_window_scaling = 1 net.ipv4.icmp_echo_ignore_all = 0 net.ipv4.icmp_echo_ignore_broadcasts = 1 net.ipv4.tcp_sack = 0 net.ipv4.tcp_keepalive_probes = 5 net.ipv4.tcp_keepalive_intvl = 30 net.ipv4.tcp_retries2 = 5 net.ipv4.tcp_max_orphans = 262144 net.ipv4.tcp_orphan_retries = 3 net.ipv4.tcp_reordering = 5 net.ipv4.tcp_retrans_collapse = 0 net.ipv4.tcp_wmem = 51200 131072 4194304 net.ipv4.tcp_rmem = 51200 131072 4194304 net.ipv4.tcp_timestamps = 1 net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_tw_recycle = 1
net.netfilter.nf_conntrack_max = 655350 net.netfilter.nf_conntrack_tcp_timeout_established = 90 net.netfilter.nf_conntrack_tcp_timeout_close_wait = 30 net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 60 net.netfilter.nf_conntrack_tcp_timeout_time_wait = 60
[root@localhost ~]# 优化后的并发可以单台服务器可以达到：61525 [root@localhost ~]# date 2017年 11月 29日 星期三 22:23:51 CST [root@localhost ~]# ss -ant | awk 'NR>1 {++s[$1]} END {for(k in s) print k,s[k]}' LAST-ACK 327 SYN-RECV 255 ESTAB 61525 FIN-WAIT-1 615 CLOSING 6 FIN-WAIT-2 15732 TIME-WAIT 12157 LISTEN 15 参考地址： https://www.cnblogs.com/fczjuever/archive/2013/04/17/3026694.html https://www.cnblogs.com/dasn/articles/5566001.html
