Solution to apache time_wait problem of too many connections

Recently, it was found that there were too many connections between apache and load balancer, and most of them were time_wait. After adjusting apache2.conf, there was no effect.

By adjusting the kernel parameters:

vi /etc/sysctl.conf

Edit the file to 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, execute /sbin/ sysctl-p for the parameters to take effect.

net.ipv4.tcp_syncookies = 1 means syn cookies is turned on. When syn waiting queue overflow occurs, cookies is enabled for processing, which can prevent a small number of syn attacks. The default value is 0, indicating shutdown.

net.ipv4.tcp_tw_reuse = 1  Represents enabling reuse. Allows you to  time-wait sockets  Reapply to new  tcp  Connection, default is  0  Is closed; 

net.ipv4.tcp_tw_recycle = 1  According to open  tcp  In the connection  time-wait sockets  Quick recycle, default is  0  , means closed. 

net.ipv4.tcp_fin_timeout  Modify the line jin's default  timeout  time 

This solves the problem of too many connections to apache time_wait.