服务器TIME_WAIT状态过多如何解决？
最近部署了一台zabbix-server和zabbix-agent，在查看tcp连接的时候显示time_wait巨多
[root@zabbix-server alertscripts]# netstat -antp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 2690/mysqld
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1093/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1348/master
tcp 0 0 0.0.0.0:10050 0.0.0.0:* LISTEN 37538/zabbix_agentd
tcp 0 0 0.0.0.0:10051 0.0.0.0:* LISTEN 41728/zabbix_server
tcp 0 0 127.0.0.1:10050 127.0.0.1:50420 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50418 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50566 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50410 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50422 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50404 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50397 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50396 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50530 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50528 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50424 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50430 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50585 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50522 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50494 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50486 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50428 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50510 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50562 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50412 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50514 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50556 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50490 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50402 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50580 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50478 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50436 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50434 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50542 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50406 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50400 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50394 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50540 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50426 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50482 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50578 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50432 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50444 TIME_WAIT -
tcp 0 232 192.168.20.10:22 192.168.20.1:61855 ESTABLISHED 67497/sshd: root@pt
tcp 0 0 127.0.0.1:10050 127.0.0.1:50520 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50438 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50414 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50488 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50458 TIME_WAIT -
tcp 0 0 192.168.20.10:10051 192.168.20.11:51946 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50584 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50568 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50546 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50476 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50446 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50448 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50442 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50552 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50560 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50472 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50538 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50498 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50504 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50570 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50416 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50508 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50576 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50518 TIME_WAIT -
tcp 0 0 127.0.0.1:10050 127.0.0.1:50468 TIME_WAIT -
tcp6 0 0 :::80 :::* LISTEN 3388/httpd
tcp6 0 0 :::22 :::* LISTEN 1093/sshd
tcp6 0 0 ::1:25 :::* LISTEN 1348/master
tcp6 0 0 :::10050 :::* LISTEN 37538/zabbix_agentd
tcp6 0 0 :::10051 :::* LISTEN 41728/zabbix_server
tcp6 0 0 192.168.20.10:80 192.168.20.1:52699 TIME_WAIT -
tcp6 0 0 ::1:10051 ::1:34078 TIME_WAIT -
tcp6 0 0 192.168.20.10:80 192.168.20.1:52705 FIN_WAIT2 76819/httpd
tcp6 0 0 192.168.20.10:80 192.168.20.1:59917 TIME_WAIT -
tcp6 0 0 ::1:10051 ::1:34016 TIME_WAIT -
tcp6 0 0 ::1:10051 ::1:33984 TIME_WAIT -
tcp6 0 0 ::1:10051 ::1:34130 TIME_WAIT -
tcp6 0 0 ::1:10051 ::1:34040 TIME_WAIT -
tcp6 0 0 192.168.20.10:80 192.168.20.1:52700 TIME_WAIT - 解决方法：在/etc/sysctl.conf里面修改两个内核参数
vim/etc/sysctl.conf
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
参数的意思是打开系统的time_wait的重用和快速回收
然后执行 sysctl -p使之生效
[root@zabbix-server alertscripts]# sysctl -p
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
效果：
time_wait状态会逐渐减少至正常
[root@zabbix-server alertscripts]# netstat -anplut
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 2690/mysqld
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1093/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1348/master
tcp 0 0 0.0.0.0:10050 0.0.0.0:* LISTEN 37538/zabbix_agentd
tcp 0 0 0.0.0.0:10051 0.0.0.0:* LISTEN 41728/zabbix_server
tcp 0 36 192.168.20.10:22 192.168.20.1:61855 ESTABLISHED 67497/sshd: root@pt
tcp6 0 0 :::80 :::* LISTEN 3388/httpd
tcp6 0 0 :::22 :::* LISTEN 1093/sshd
tcp6 0 0 ::1:25 :::* LISTEN 1348/master
tcp6 0 0 :::10050 :::* LISTEN 37538/zabbix_agentd
tcp6 0 0 :::10051 :::* LISTEN 41728/zabbix_server
tcp6 0 0 192.168.20.10:80 192.168.20.1:52842 TIME_WAIT -
tcp6 0 0 192.168.20.10:80 192.168.20.1:52844 ESTABLISHED 76729/httpd
tcp6 0 0 192.168.20.10:80 192.168.20.1:52843 ESTABLISHED 76775/httpd
tcp6 0 0 192.168.20.10:80 192.168.20.1:52835 TIME_WAIT -
tcp6 0 0 192.168.20.10:80 192.168.20.1:52839 TIME_WAIT -
tcp6 0 0 192.168.20.10:80 192.168.20.1:52831 TIME_WAIT -
tcp6 0 0 192.168.20.10:80 192.168.20.1:52841 TIME_WAIT -
tcp6 0 0 192.168.20.10:80 192.168.20.1:52826 TIME_WAIT -
tcp6 0 0 192.168.20.10:80 192.168.20.1:52836 TIME_WAIT -
udp 0 0 127.0.0.1:323 0.0.0.0:* 704/chronyd
udp6 0 0 ::1:323 :::* 704/chronyd