?

优化/etc/sysctl.conf

增加：
?kernel.shmmax = 68719476736
?# Controls the maximum number of shared memory segments, in pages
?kernel.shmall = 4294967296
???
??????? #syncookie
??????? net.ipv4.tcp_max_syn_backlog = 65536
??????? net.core.netdev_max_backlog =? 32768
??????? net.core.somaxconn = 32768

??????? net.core.wmem_default = 8388608
??????? net.core.rmem_default = 8388608
??????? net.core.rmem_max = 16777216
??????? net.core.wmem_max = 16777216

??????? net.ipv4.tcp_timestamps = 0
??????? net.ipv4.tcp_synack_retries = 2
??????? net.ipv4.tcp_syn_retries = 2
??????? #time_wait
??????? net.ipv4.tcp_syncookies = 1
??????? net.ipv4.tcp_tw_recycle = 1
??????? net.ipv4.tcp_fin_timeout = 5
??????? net.ipv4.tcp_tw_reuse = 1

??????? net.ipv4.tcp_mem = 94500000 915000000 927000000
??????? net.ipv4.tcp_max_orphans = 3276800
??????? net.ipv4.ip_local_port_range = 1024? 65535

?

?

?

?

?

查看mysql连接

#netstat -anp | grep mysql | wc -l

netstat -n | awk '/^tcp/ {++state[$NF]} END {for(key in state) print key,"\t",state[key]}'

查看TIME_WAIT连接数
netstat -ae|grep "TIME_WAIT" |wc -l

netstat -n | awk '/^tcp/ {++state[$NF]} END {for(key in state) print key,"\t",state[key]}'

查找较多time_wait连接
netstat -n|grep TIME_WAIT|awk '{print $5}'|sort|uniq -c|sort -rn|head -n20

?

?

?

?

?

===================================实例测试

1 ） 系统说明

服务器说明：

两台 CentOS release 5.4 (Final) 32 位， 1 颗 CPU 8 核

?

a.?????? 服务器 1

服务： Nginx + php (fpm)

nginx 开启的进程数 8

FastCGI 进程数 128

?

b.?????? 服务器 2

服务 :Memcache+mysql

memcache 替代 session ，开启两个端口，分别分配 1024M;

?

?

2) 模拟场景 : 首页，登录，退出

并发量： 900

?

?

?

=============== 系统说明

?

#cat /etc/issue

CentOS release 5.4 (Final)