keepalived 自生存活监测
vrrp script
keepalived调用外部的辅助脚本进行资源监控，并根据监控的结果状态能实现优先动态调整。也就是keepalived监测自身，当自身挂了之后主动让出VIP。
需要对
vrrp_script:自定义资源监控脚本，vrrp实例根据脚本返回值进行下一步操作，脚本可被多个实例调用。
track_script:调用vrrp_script定义的脚本去监控资源，定义在实例之内，调用事先定义的vrrp_script
vrrp_script
vrrp_script { #定义 名称 script | #定义脚本所在的位置 interval #间隔多久执行一次脚本 timeout #多久么有返回值就失败 weight #权重-254到254，如果监测失败则当前优先权减去次权重，如果 rise #服务器下线了开始监测多少测成功则上线 fall #服务器连续检测多少测都失败，则标记为失败 user USERNAME [GROUPNAME] #一般为root init_fail #在未进行监测时，默认为失败。}
keepalived+lvs实现自生存活监测
由于lvs没有进程，所以只能使用脚本去访问第三方的设备来探测自己是否存活，比如本机的端口，或者网关。
配置方法1
1.创建出一个ping脚本
[root@s1 ~]# vim /etc/keepalived/ping.sh#!/bin/bashping -c 2 172.20.0.1 &> /dev/nullif [ $? -eq 0 ];then exit 0else exit 2fi
2.修改keepalived配置文件
vrrp_script check { #定义脚本 script /etc/keepalived/ping.sh interval 2 weight -50 fall 3 rise 5 timeout 2}vrrp_instance VI_1 { state Master interface ens33 virtual_router_id 27 priority 100 advert_int 2 authentication { auth_type PASS auth_pass 1111 } unicast_src_ip 172.20.27.10 unicast_peer { 172.20.27.11 } virtual_ipaddress { 172.20.27.100 dev ens33 label ens33:0 } track_script { #调用脚本 check }}#在另一台主机上也执行相同的配置 3.重启服务后查看vip
[root@s1 ~]# ifconfigens33: flags=4163 mtu 1500 inet 172.20.27.10 netmask 255.255.0.0 broadcast 172.20.255.255 inet6 fe80::20c:29ff:fec5:123c prefixlen 64 scopeid 0x20 ether 00:0c:29:c5:12:3c txqueuelen 1000 (Ethernet) RX packets 540749 bytes 43766835 (41.7 MiB) RX errors 0 dropped 12 overruns 0 frame 0 TX packets 78080 bytes 11718371 (11.1 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0ens33:0: flags=4163 mtu 1500 inet 172.20.27.100 netmask 255.255.255.255 broadcast 0.0.0.0 ether 00:0c:29:c5:12:3c txqueuelen 1000 (Ethernet)#vip在当前的主机上
4.测试
更改ping.sh脚本中的地址到一个不存在的地址，并对keepalived日志进行跟踪
[root@s1 ~]# tail -f /var/log/messages Jun 8 15:48:37 s1 Keepalived_healthcheckers[10792]: SMTP alert successfully sent.Jun 8 15:50:05 s1 Keepalived_vrrp[10793]: /etc/keepalived/ping.sh exited due to signal 15 #脚本监测失败Jun 8 15:50:07 s1 Keepalived_vrrp[10793]: /etc/keepalived/ping.sh exited due to signal 15 #脚本监测失败Jun 8 15:50:09 s1 Keepalived_vrrp[10793]: VRRP_Script(check) timed out #连续三次次超时Jun 8 15:50:09 s1 Keepalived_vrrp[10793]: VRRP_Instance(VI_1) Changing effective priority from 100 to 50 #优先级从100降低到50Jun 8 15:50:09 s1 Keepalived_vrrp[10793]: /etc/keepalived/ping.sh exited due to signal 15 #脚本监测失败Jun 8 15:50:11 s1 Keepalived_vrrp[10793]: VRRP_Instance(VI_1) Received advert with higher priority 80, ours 50 #发现备节点的优先级比本机高，主动让出vip
查看vip是否在s2节点上
[root@s2 ~]# ifconfigens33: flags=4163 mtu 1500 inet 172.20.27.11 netmask 255.255.0.0 broadcast 172.20.255.255 inet6 fe80::20c:29ff:fe4d:1ce3 prefixlen 64 scopeid 0x20 ether 00:0c:29:4d:1c:e3 txqueuelen 1000 (Ethernet) RX packets 535679 bytes 43641678 (41.6 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 36428 bytes 3457323 (3.2 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0ens33:0: flags=4163 mtu 1500 inet 172.20.27.100 netmask 255.255.255.255 broadcast 0.0.0.0 ether 00:0c:29:4d:1c:e3 txqueuelen 1000 (Ethernet)#VIP在备节点上
配置方法2
在脚本中判断lvs后端的服务器是否存在，如果存不存在，则创建一个文件
在vrrp_script中判断文件是否存在如果文件存在，则表示自己挂了，将自己的优先级减低让出vip
script "/bin/bash -c '[[ -f /etc/keepalived/down ]]' && exit 7 || exit 0"
HAProxy+keepalived的检测机制
HAProxy+keepalived的检测方式可以使用curl HAProxy的状态页面，或者使用killall -0对HAProxy发送一个信号，如果进程存在则返回值为0，如果进程不存在则返回值为非0
配置方法1
1.创建检测脚本
[root@s1 ~]# vim /etc/keepalived/curl.sh#!/bin/bashcurl -I http://172.20.27.10:9000/haproxy-status &> /dev/nullif [ $? -eq 0 ];then exit 0else exit 2fi
2.修改keepalived配置文件定义vrrp_script和调用
root@s1 ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalivedglobal_defs { notification_email { root@mylinuxops.com } notification_email_from root@mylinuxops.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id s1.mylinuxops.com vrrp_skip_check_adv_addr #vrrp_strict vrrp_iptables vrrp_garp_interval 0 vrrp_gna_interval 0}vrrp_script check { #定义脚本名 script /etc/keepalived/curl.sh #定义脚本路径 interval 2 weight -50 fall 3 rise 5 timeout 2}vrrp_instance VI_1 { state Master interface ens33 virtual_router_id 27 priority 100 advert_int 2 authentication { auth_type PASS auth_pass 1111 } unicast_src_ip 172.20.27.10 unicast_peer { 172.20.27.11 } virtual_ipaddress { 172.20.27.100 dev ens33 label ens33:0 } track_script { check #调用脚本 }}#另一台服务器也执行相同的操作 3.重启服务后查看vip是否存在
[root@s1 ~]# ifconfigens33: flags=4163 mtu 1500 inet 172.20.27.10 netmask 255.255.0.0 broadcast 172.20.255.255 inet6 fe80::20c:29ff:fec5:123c prefixlen 64 scopeid 0x20 ether 00:0c:29:c5:12:3c txqueuelen 1000 (Ethernet) RX packets 639634 bytes 52435377 (50.0 MiB) RX errors 0 dropped 12 overruns 0 frame 0 TX packets 103375 bytes 13944325 (13.2 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0ens33:0: flags=4163 mtu 1500 inet 172.20.27.100 netmask 255.255.255.255 broadcast 0.0.0.0 ether 00:0c:29:c5:12:3c txqueuelen 1000 (Ethernet)lo: flags=73 mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10 loop txqueuelen 1000 (Local Loopback) RX packets 4511 bytes 317479 (310.0 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 4511 bytes 317479 (310.0 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
4.停止haproxy并追踪日志
[root@s1 ~]# tail -f /var/log/messages Jun 8 17:15:16 s1 Keepalived_vrrp[16954]: /etc/keepalived/curl.sh exited with status 2Jun 8 17:15:18 s1 Keepalived_vrrp[16954]: /etc/keepalived/curl.sh exited with status 2Jun 8 17:15:20 s1 Keepalived_vrrp[16954]: /etc/keepalived/curl.sh exited with status 2 #连续3次无法curl到页面Jun 8 17:15:20 s1 Keepalived_vrrp[16954]: VRRP_Script(check) failedJun 8 17:15:20 s1 Keepalived_vrrp[16954]: VRRP_Instance(VI_1) Changing effective priority from 100 to 50 #自动将优先级降低50Jun 8 17:15:22 s1 Keepalived_vrrp[16954]: VRRP_Instance(VI_1) Received advert with higher priority 80, ours 50 #发现备的优先级比自己高Jun 8 17:15:22 s1 Keepalived_vrrp[16954]: VRRP_Instance(VI_1) Entering BACKUP STATE #自己转为备Jun 8 17:15:22 s1 Keepalived_vrrp[16954]: VRRP_Instance(VI_1) removing protocol VIPs.Jun 8 17:15:22 s1 Keepalived_vrrp[16954]: /etc/keepalived/curl.sh exited with status 2Jun 8 17:15:24 s1 Keepalived_vrrp[16954]: /etc/keepalived/curl.sh exited with status 2
配置方法2
使用killall -0 haproxy对进程发起信号
1.安装killall
[root@s1 ~]# yum install psmisc -y
2.修改配置文件
[root@s1 ~]# vim /etc/keepalived/keepalived.conf ! Configuration File for keepalivedglobal_defs { notification_email { root@mylinuxops.com } notification_email_from root@mylinuxops.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id s1.mylinuxops.com vrrp_skip_check_adv_addr #vrrp_strict vrrp_iptables vrrp_garp_interval 0 vrrp_gna_interval 0}vrrp_script check { #定义脚本名称 script "killall -0 haproxy" #由于脚本中只有一条命令，直接写在这里就行，无需再写脚本 interval 2 weight -50 fall 3 rise 5 timeout 2}vrrp_instance VI_1 { state Master interface ens33 virtual_router_id 27 priority 100 advert_int 2 authentication { auth_type PASS auth_pass 1111 } unicast_src_ip 172.20.27.10 unicast_peer { 172.20.27.11 } virtual_ipaddress { 172.20.27.100 dev ens33 label ens33:0 } track_script { check #调用脚本 }} 3.重启服务后查看vip是否存在
[root@s1 ~]# ifconfigens33: flags=4163 mtu 1500 inet 172.20.27.10 netmask 255.255.0.0 broadcast 172.20.255.255 inet6 fe80::20c:29ff:fec5:123c prefixlen 64 scopeid 0x20 ether 00:0c:29:c5:12:3c txqueuelen 1000 (Ethernet) RX packets 639634 bytes 52435377 (50.0 MiB) RX errors 0 dropped 12 overruns 0 frame 0 TX packets 103375 bytes 13944325 (13.2 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0ens33:0: flags=4163 mtu 1500 inet 172.20.27.100 netmask 255.255.255.255 broadcast 0.0.0.0 ether 00:0c:29:c5:12:3c txqueuelen 1000 (Ethernet)lo: flags=73 mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10 loop txqueuelen 1000 (Local Loopback) RX packets 4511 bytes 317479 (310.0 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 4511 bytes 317479 (310.0 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
4.停止haproxy并追踪日志
[root@s1 ~]# tail -f /var/log/messages Jun 8 17:30:53 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1Jun 8 17:30:55 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1Jun 8 17:30:57 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1Jun 8 17:30:57 s1 Keepalived_vrrp[18639]: VRRP_Script(check) failed #连续监测3次失败Jun 8 17:30:57 s1 Keepalived_vrrp[18639]: VRRP_Instance(VI_1) Changing effective priority from 100 to 50 #优先级降低为50Jun 8 17:30:59 s1 Keepalived_vrrp[18639]: VRRP_Instance(VI_1) Received advert with higher priority 80, ours 50 #发现有优先级比当前高的主机Jun 8 17:30:59 s1 Keepalived_vrrp[18639]: VRRP_Instance(VI_1) Entering BACKUP STATE #自动将为备Jun 8 17:30:59 s1 Keepalived_vrrp[18639]: VRRP_Instance(VI_1) removing protocol VIPs. #移除vipJun 8 17:30:59 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1Jun 8 17:31:01 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1Jun 8 17:31:03 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1