command to view the number of time_wait connections netstat-ae|grep "time_wait" |wc-l

command to view the number of time_wait connections netstat-ae|grep "time_wait" |wc-l the morning log in to the server when entering Netstat-an|grep MySQL Found a large number of time_wait states connected tcp        0      0 127.0.0.1:3306              127.0.0.1:41378              time_wait tcp         0      0 127.0.0.1:3306               127.0.0.1:41379              time_wait tcp        0      0 127.0.0.1:3306              127.0.0.1:39352              time_wait tcp         0      0 127.0.0.1:3306               127.0.0.1:39350             TIME_WAIT TCP         0      0 127.0.0.1:3306               127.0.0.1:35763              time_wait tcp        0       0 127.0.0.1:3306               127.0.0.1:39372             TIME_WAIT TCP         0      0 127.0.0.1:3306               127.0.0.1:39373              time_wait tcp        0       0 127.0.0.1:3306              127.0.0.1:41176              time_wait       by adjusting kernel parameters to resolve Vi/etc/sysctl.conf
Edit the file and add the following: net.ipv4.tcp_syncookies = 1 Net.ipv4.tcp_tw_reuse = 1 Net.ipv4.tcp_tw_recycle = 1 Net.ipv4.tcp_fin_timeout = 30 then executes the/sbin/sysctl-p to allow the parameters to take effect. net.ipv4.tcp_syncookies = 1Indicates that the SYN cookie is opened. When the SYN wait queue overflow occurs, cookies are enabled to handle, to prevent a small number of SYN attacks, the default is 0, indicating shutdown;
net.ipv4.tcp_tw_reuse = 1Indicates open reuse. Allows time-wait sockets to be re used for a new TCP connection, which defaults to 0, indicating shutdown;
net.ipv4.tcp_tw_recycle = 1Represents a quick recycle of time-wait sockets on a TCP connection, which defaults to 0, indicating shutdown.
Net.ipv4.tcp_fin_timeoutAfter modifying the system default TIMEOUT time changes, then use the command to view the number of time_wait connections netstat-ae|grep "time_wait" |wc–l
found that a large number of time_wait no longer exist, the MySQL process occupancy rate quickly down, the site access is normal. However, many times, the presence of a large number of time_wait state of the connection, often because the Web site program code does not use Mysql.colse (), resulting in a large number of MySQL time_wait.