keepalived調用外部的輔助腳本進行資源監控,並根據監控的結果狀態能實現優先動態調整。也就是keepalived監測自身,當自身掛了以後主動讓出VIP。
須要對
vrrp_script:自定義資源監控腳本,vrrp實例根據腳本返回值進行下一步操做,腳本可被多個實例調用。
track_script:調用vrrp_script定義的腳本去監控資源,定義在實例以內,調用事先定義的vrrp_scriptlinux
vrrp_scriptvim
vrrp_script <SCRIPT_NAME> { #定義 名稱 script <STRING>|<QUOTED-STRING> #定義腳本所在的位置 interval <INTEGER> #間隔多久執行一次腳本 timeout <INTEGER> #多久麼有返回值就失敗 weight <INTEGER:-254..254> #權重-254到254,若是監測失敗則當前優先權減去次權重,若是 rise <INTEGER> #服務器下線了開始監測多少測成功則上線 fall <INTEGER> #服務器連續檢測多少測都失敗,則標記爲失敗 user USERNAME [GROUPNAME] #通常爲root init_fail #在未進行監測時,默認爲失敗。 }
因爲lvs沒有進程,因此只能使用腳本去訪問第三方的設備來探測本身是否存活,好比本機的端口,或者網關。後端
1.建立出一個ping腳本bash
[root@s1 ~]# vim /etc/keepalived/ping.sh #!/bin/bash ping -c 2 172.20.0.1 &> /dev/null if [ $? -eq 0 ];then exit 0 else exit 2 fi
2.修改keepalived配置文件服務器
vrrp_script check { #定義腳本 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 { #調用腳本 check } } #在另外一臺主機上也執行相同的配置
3.重啓服務後查看vipcurl
[root@s1 ~]# ifconfig ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> 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<link> 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 0 ens33:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> 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在當前的主機上
4.測試
更改ping.sh腳本中的地址到一個不存在的地址,並對keepalived日誌進行跟蹤ide
[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 #腳本監測失敗 Jun 8 15:50:07 s1 Keepalived_vrrp[10793]: /etc/keepalived/ping.sh exited due to signal 15 #腳本監測失敗 Jun 8 15:50:09 s1 Keepalived_vrrp[10793]: VRRP_Script(check) timed out #連續三次次超時 Jun 8 15:50:09 s1 Keepalived_vrrp[10793]: VRRP_Instance(VI_1) Changing effective priority from 100 to 50 #優先級從100下降到50 Jun 8 15:50:09 s1 Keepalived_vrrp[10793]: /etc/keepalived/ping.sh exited due to signal 15 #腳本監測失敗 Jun 8 15:50:11 s1 Keepalived_vrrp[10793]: VRRP_Instance(VI_1) Received advert with higher priority 80, ours 50 #發現備節點的優先級比本機高,主動讓出vip
查看vip是否在s2節點上oop
[root@s2 ~]# ifconfig ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> 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<link> 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 0 ens33:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> 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在備節點上
在腳本中判斷lvs後端的服務器是否存在,若是存不存在,則建立一個文件
在vrrp_script中判斷文件是否存在若是文件存在,則表示本身掛了,將本身的優先級減低讓出vip測試
script "/bin/bash -c '[[ -f /etc/keepalived/down ]]' && exit 7 || exit 0"
HAProxy+keepalived的檢測方式能夠使用curl HAProxy的狀態頁面,或者使用killall -0對HAProxy發送一個信號,若是進程存在則返回值爲0,若是進程不存在則返回值爲非0url
1.建立檢測腳本
[root@s1 ~]# vim /etc/keepalived/curl.sh #!/bin/bash curl -I http://172.20.27.10:9000/haproxy-status &> /dev/null if [ $? -eq 0 ];then exit 0 else exit 2 fi
2.修改keepalived配置文件定義vrrp_script和調用
root@s1 ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_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 { #定義腳本名 script /etc/keepalived/curl.sh #定義腳本路徑 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 #調用腳本 } } #另外一臺服務器也執行相同的操做
3.重啓服務後查看vip是否存在
[root@s1 ~]# ifconfig ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> 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<link> 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 0 ens33:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> 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<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> 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.中止haproxy並追蹤日誌
[root@s1 ~]# tail -f /var/log/messages Jun 8 17:15:16 s1 Keepalived_vrrp[16954]: /etc/keepalived/curl.sh exited with status 2 Jun 8 17:15:18 s1 Keepalived_vrrp[16954]: /etc/keepalived/curl.sh exited with status 2 Jun 8 17:15:20 s1 Keepalived_vrrp[16954]: /etc/keepalived/curl.sh exited with status 2 #連續3次沒法curl到頁面 Jun 8 17:15:20 s1 Keepalived_vrrp[16954]: VRRP_Script(check) failed Jun 8 17:15:20 s1 Keepalived_vrrp[16954]: VRRP_Instance(VI_1) Changing effective priority from 100 to 50 #自動將優先級下降50 Jun 8 17:15:22 s1 Keepalived_vrrp[16954]: VRRP_Instance(VI_1) Received advert with higher priority 80, ours 50 #發現備的優先級比本身高 Jun 8 17:15:22 s1 Keepalived_vrrp[16954]: VRRP_Instance(VI_1) Entering BACKUP STATE #本身轉爲備 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 2 Jun 8 17:15:24 s1 Keepalived_vrrp[16954]: /etc/keepalived/curl.sh exited with status 2
使用killall -0 haproxy對進程發起信號
1.安裝killall
[root@s1 ~]# yum install psmisc -y
2.修改配置文件
[root@s1 ~]# vim /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_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 { #定義腳本名稱 script "killall -0 haproxy" #因爲腳本中只有一條命令,直接寫在這裏就行,無需再寫腳本 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 #調用腳本 } }
3.重啓服務後查看vip是否存在
[root@s1 ~]# ifconfig ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> 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<link> 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 0 ens33:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> 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<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> 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.中止haproxy並追蹤日誌
[root@s1 ~]# tail -f /var/log/messages Jun 8 17:30:53 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1 Jun 8 17:30:55 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1 Jun 8 17:30:57 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1 Jun 8 17:30:57 s1 Keepalived_vrrp[18639]: VRRP_Script(check) failed #連續監測3次失敗 Jun 8 17:30:57 s1 Keepalived_vrrp[18639]: VRRP_Instance(VI_1) Changing effective priority from 100 to 50 #優先級下降爲50 Jun 8 17:30:59 s1 Keepalived_vrrp[18639]: VRRP_Instance(VI_1) Received advert with higher priority 80, ours 50 #發現有優先級比當前高的主機 Jun 8 17:30:59 s1 Keepalived_vrrp[18639]: VRRP_Instance(VI_1) Entering BACKUP STATE #自動將爲備 Jun 8 17:30:59 s1 Keepalived_vrrp[18639]: VRRP_Instance(VI_1) removing protocol VIPs. #移除vip Jun 8 17:30:59 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1 Jun 8 17:31:01 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1 Jun 8 17:31:03 s1 Keepalived_vrrp[18639]: /usr/bin/killall -0 haproxy exited with status 1