lvs+keepalived健康檢查
LVS是Linux Virtual Server的簡稱，即Linux虛擬服務器。使用LVS技術要達到的目標是：通過LVS提供的負載均衡技術和Linux操作系統實現一個高性能、高可用的服務器羣集，它具有良好可靠性、可擴展性和可操作性。從而以低廉的成本實現最優的服務性能。
二、網絡拓撲
三、接口IP及屬性配置
1，在Master配置接口IP如下：
[root@localhost network-scripts]# ifconfig ens33:flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.230.10 netmask255.255.255.0 broadcast 192.168.230.255 inet6 fe80::250:56ff:fe9a:55c5 prefixlen 64 scopeid0x20<link> ether 00:50:56:9a:55:c5 txqueuelen 1000 (Ethernet) RX packets 1201 bytes 94251 (92.0KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 5964 bytes 390181(381.0 KiB) TX errors 0 dropped 0 overruns0 carrier 0 collisions 0 ens33:0:flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.230.100 netmask255.255.255.255 broadcast192.168.230.100 ether 00:50:56:9a:55:c5 txqueuelen 1000 (Ethernet)
2，在Slave配置接口IP如下：
[root@localhost ~]# ifconfig ens33:flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.230.11 netmask255.255.255.0 broadcast 192.168.230.255 inet6 fe80::250:56ff:fe9a:62e8 prefixlen 64 scopeid0x20<link> ether 00:50:56:9a:62:e8 txqueuelen 1000 (Ethernet) RX packets 3 bytes 620 (620.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 50 bytes 7844 (7.6KiB) TX errors 0 dropped 0 overruns0 carrier 0 collisions 0 ens33:0:flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.230.100 netmask255.255.255.255 broadcast192.168.230.100 ether 00:50:56:9a:62:e8 txqueuelen 1000 (Ethernet)
3，在rs1上配置接口IP如下：
[root@localhost]# ifconfig ens33:flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.230.12 netmask255.255.255.0 broadcast 192.168.230.255 inet6 fe80::250:56ff:fe9a:daa prefixlen 64 scopeid0x20<link> ether 00:50:56:9a:0d:aa txqueuelen 1000 (Ethernet) RX packets 162543 bytes 11199233(10.6 MiB) RX errors 0 dropped 66 overruns 0 frame 0 TX packets 74236 bytes 9216209(8.7 MiB) TX errors 0 dropped 0 overruns0 carrier 0 collisions 0 lo:0:flags=73<UP,LOOPBACK,RUNNING> mtu65536 inet 192.168.230.100 netmask255.255.255.255 loop txqueuelen 0 (Local Loopback)
4，在rs2上配置接口IP如下：
[root@localhost]# ifconfig ens33:flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.230.13 netmask255.255.255.0 broadcast 192.168.230.255 inet6 fe80::250:56ff:fe9a:2be1 prefixlen 64 scopeid0x20<link> ether 00:50:56:9a:2b:e1 txqueuelen 1000 (Ethernet) RX packets 161840 bytes 11150452(10.6 MiB) RX errors 0 dropped 44 overruns 0 frame 0 TX packets 73427 bytes 7893814(7.5 MiB) TX errors 0 dropped 0 overruns0 carrier 0 collisions 0 lo:0: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 192.168.230.100 netmask255.255.255.255 loop txqueuelen 0 (Local Loopback)
5，在Master和Slave上開啓轉發功能
[root@localhost ~]# echo "1">/proc/sys/net/ipv4/ip_forward
6，在rs1和rs2配置接口屬性
[root@localhost ~]# echo "1">/proc/sys/net/ipv4/conf/lo/arp_ignore [root@localhost ~]# echo "2">/proc/sys/net/ipv4/conf/lo/arp_announce [root@localhost ~]# echo "1">/proc/sys/net/ipv4/conf/all/arp_ignore [root@localhost ~]# echo "2">/proc/sys/net/ipv4/conf/all/arp_announce [root@localhost ~]# sysctl -p net.ipv4.conf.ens33.arp_announce = 2 net.ipv4.conf.ens33.arp_ignore = 1 net.ipv4.conf.lo.arp_announce = 2 net.ipv4.conf.lo.arp_ignore = 1
四、軟件安裝
1，在Master上安裝ipvsadm和keepalived
[root@localhost ~]# yum install -ykeepalived ipvsadm
2，同樣在Slave上安裝ipvsadm和keepalived
[root@localhost ~]# yum install -ykeepalived ipvsadm
3，在rs1和rs2安裝測試服務，這裏安裝httpd服務，具體服務配置請參考官方配置文檔。
[root@localhost htdocs]# yum install -yhttpd
訪問192.168.230.12服務：
訪問192.168.230.13服務：
五、keepalived配置
1，TCP健康檢查配置如下：
[root@localhost keepalived]# catkeepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 55
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.230.100
}
}
virtual_server 192.168.230.100 80 {
delay_loop 6
lb_algo rr
lb_kind DR
#persistence_timeout 50
protocol TCP
real_server 192.168.230.12 80 {
weight 1
TCP_CHECK { #tcp健康檢查
connect_port 80
connect_timeout 3
Nb_get_retry 3 #最大重試次數
delay_before_retry 5 #重試延時
}
}
real_server 192.168.230.13 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
Nb_get_retry 3
delay_before_retry 5
}
}
}
2，http健康檢查配置
[root@localhost ~]# cat/etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 55
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.230.100
}
}
virtual_server 192.168.230.100 80 {
delay_loop 6
lb_algo rr
lb_kind DR
#persistence_timeout 50
protocol TCP
real_server 192.168.230.12 80 {
weight 1
HTTP_GET {
url {
path /index.html
digest 00f6c72507d2480429e5f32dbf2de638
#digest是根據hash算出來的，算法如下：
# /usr/bin/genhash -s 192.168.230.13 -p 80-u /index.html
#注意！如果不加digest經測試發現，當rs服務down掉後又恢復，lvs不能
#恢復調度到此rs上。即健康檢查不能恢復
}
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 5
}
}
real_server 192.168.230.13 80 {
weight 1
HTTP_GET {
url {
path /index.html
digest 4b0f20d78e6098eb5c2eed901f5f3b6e
#digest是根據hash算出來的，算法如下：
# /usr/bin/genhash -s 192.168.230.13 -p 80-u /index.html
}
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 5
}
}
}3，配置完在Master和Slave上重啓keepalived服務
[root@localhost keepalived]# servicekeepalived restart
六、測試
1，將rs1的httpd服務關閉，在客戶端訪問。
2，抓包查看，每5s發送一次重傳檢查報文。
3，http健康檢查報文，每6秒發送一次請求。
