1.环境介绍

2.配置keepalived

3.测试

1.测试负载均衡

2.测试RS高可用

3.测试LVS高可用

3.1测试lvs主服务宕机

3.2.测试lvs主服务器恢复

4.我在实验中遇到的错误

1.环境介绍

环境：centos7

RS1---RIP1:192.168.163.145

VIP 192.168.163.200

RS2---RIP2:192.168.163.146

VIP 192.168.163.200

LVS_MASTER : DIP 192.168.163.144

VIP:192.168.163.200

LVS_BACKUP: DIP 192.168.163.150

VIP:192.168.163.200

CLIENT :192.168.163.151

我使用的是LVS-DR模式来负载均衡，详情请见http://t.csdn.cn/iiU4s

ipvsadm 已经在这篇文章搭建好

2.配置keepalived

现在我们需要在两台LVS服务器都下载keepalivd

yum install keepalived -y

下载号后，我们会在/etc/keepalived的目录下找一个配置文件文件

[root@lvs-backup ~]# cd /etc/keepalived/
[root@lvs-backup keepalived]# ll
total 4
-rw-r--r--. 1 root root 1376 Aug 31 12:12 keepalived.conf

里面内容如下

! Configuration File for keepalivedglobal_defs {notification_email {acassen@firewall.locfailover@firewall.locsysadmin@firewall.loc}notification_email_from Alexandre.Cassen@firewall.locsmtp_server 192.168.200.1smtp_connect_timeout 30router_id LVS_DEVELvrrp_skip_check_adv_addrvrrp_strictvrrp_garp_interval 0vrrp_gna_interval 0
}
#上面的配置无需关注，重点关注和修改下面的配置
vrrp_instance VI_1 {state MASTER#标识当前lvs是主，根据实际lvs服务器规划确定，可选值MASTER和BACKUPinterface eth0#lvs服务器提供服务器的网卡，根据实际服务器网卡进行修改virtual_router_id 51#lvs提供的服务所属ID，目前无需修改priority 100#lvs服务器的优先级，主服务器最高，备份服务器要低于主服务器advert_int 1authentication {auth_type PASSauth_pass 1111}#virtual_ipaddress用于配置VIP和LVS服务器的网卡绑定关系，一般需要修改#示例: 192.168.116.134/24 dev ens33 label ens33:9virtual_ipaddress {192.168.200.16192.168.200.17192.168.200.18}
}
#配置lvs服务策略，相当于ipvsadm -A -t 192.168.116.134:80 -s rr，一般需要修改
virtual_server 192.168.200.100 443 {delay_loop 6lb_algo rr#配置lvs调度算法，默认轮询lb_kind NAT#配置lvs工作模式，可以改为DRpersistence_timeout 50#用于指定同一个client在多久内，只去请求第一次提供服务的RS，为查看轮询效                        果，这里需要改为0protocol TCP#TCP协议#配置RS信息，相当于ipvsadm -a -t 192.168.116.134:80 -r 192.168.116.131 -greal_server 192.168.201.100 443 {weight 1#当前RS的权重SSL_GET {#SSL_GET健康检查，一般改为HTTP_GET#两个url可以删除一个，url内的内容改为path /和status_code 200，digest删除url {path /digest ff20ad2481f97b1754ef3e12ecd3a9cc}url {path /mrtg/digest 9b3a0c85a887a256d6939da88aabd8cd}connect_timeout 3nb_get_retry 3delay_before_retry 3}}
}
#下面的配置实际是两组lvs服务的配置，含义和上面的lvs服务配置一致。如果用不到，下面的配置可以全部删除
virtual_server 10.10.10.2 1358 {delay_loop 6lb_algo rrlb_kind NATpersistence_timeout 50protocol TCPsorry_server 192.168.200.200 1358real_server 192.168.200.2 1358 {weight 1HTTP_GET {url {path /testurl/test.jspdigest 640205b7b0fc66c1ea91c463fac6334d}url {path /testurl2/test.jspdigest 640205b7b0fc66c1ea91c463fac6334d}url {path /testurl3/test.jspdigest 640205b7b0fc66c1ea91c463fac6334d}connect_timeout 3nb_get_retry 3delay_before_retry 3}}real_server 192.168.200.3 1358 {weight 1HTTP_GET {url {path /testurl/test.jspdigest 640205b7b0fc66c1ea91c463fac6334c}url {path /testurl2/test.jspdigest 640205b7b0fc66c1ea91c463fac6334c}connect_timeout 3nb_get_retry 3delay_before_retry 3}}
}virtual_server 10.10.10.3 1358 {delay_loop 3lb_algo rrlb_kind NATpersistence_timeout 50protocol TCPreal_server 192.168.200.4 1358 {weight 1HTTP_GET {url {path /testurl/test.jspdigest 640205b7b0fc66c1ea91c463fac6334d}url {path /testurl2/test.jspdigest 640205b7b0fc66c1ea91c463fac6334d}url {path /testurl3/test.jspdigest 640205b7b0fc66c1ea91c463fac6334d}connect_timeout 3nb_get_retry 3delay_before_retry 3}}real_server 192.168.200.5 1358 {weight 1HTTP_GET {url {path /testurl/test.jspdigest 640205b7b0fc66c1ea91c463fac6334d}url {path /testurl2/test.jspdigest 640205b7b0fc66c1ea91c463fac6334d}url {path /testurl3/test.jspdigest 640205b7b0fc66c1ea91c463fac6334d}connect_timeout 3nb_get_retry 3delay_before_retry 3}}
}

在两台机器上修改我们需要修改的配置

LVS_MASTER

[root@lvs ~]# cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalivedglobal_defs {notification_email {acassen@firewall.locfailover@firewall.locsysadmin@firewall.loc}notification_email_from Alexandre.Cassen@firewall.locsmtp_server 192.168.200.1smtp_connect_timeout 30router_id LVS_DEVELvrrp_skip_check_adv_addr#vrrp_strictvrrp_garp_interval 0vrrp_gna_interval 0
}vrrp_instance VI_1 {state MASTERinterface ens33virtual_router_id 51priority 200advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.163.200/24 brd 192.168.163.255  dev ens33 label ens33:200}
}virtual_server 192.168.163.200 80 {delay_loop 6lb_algo rrlb_kind DRnat_mask 255.255.255.0persistence_timeout 0protocol TCPreal_server 192.168.163.145 80 {weight 1HTTP_GET {url {path /index.htmlstatus_code 200}connect_timeout 3nb_get_retry 3delay_before_retry 3}}real_server 192.168.163.146 80 {weight 1HTTP_GET {url {path /index.htmlstatus_code 200}connect_timeout 3nb_get_retry 3delay_before_retry 3}}}

LVS_BACKUP

[root@lvs-backup keepalived]# cat keepalived.conf 
! Configuration File for keepalivedglobal_defs {notification_email {acassen@firewall.locfailover@firewall.locsysadmin@firewall.loc}notification_email_from Alexandre.Cassen@firewall.locsmtp_server 192.168.200.1smtp_connect_timeout 30router_id LVS_DEVELvrrp_skip_check_adv_addr#vrrp_strictvrrp_garp_interval 0vrrp_gna_interval 0
}vrrp_instance VI_1 {state BACKUPinterface ens33virtual_router_id 51priority 180advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.163.200/24 brd 192.168.163.255  dev ens33 label ens33:200}
}virtual_server 192.168.163.200 80 {delay_loop 6lb_algo rrlb_kind DRnat_mask 255.255.255.0persistence_timeout 0protocol TCPreal_server 192.168.163.145 80 {weight 1HTTP_GET {url {path /index.htmlstatus_code 200}connect_timeout 3nb_get_retry 3delay_before_retry 3}}real_server 192.168.163.146 80 {weight 1HTTP_GET {url {path /index.htmlstatus_code 200}connect_timeout 3nb_get_retry 3delay_before_retry 3}}}

注意：主服务的优先级要高于备份服务器

在两台服务器上开启keepalived服务

[root@lvs ~]# systemctl restart keepalived

上述步骤执行完毕后，可以在lvs主服务器和备份服务器分别执行ifconfig命令，可以查看到VIP被绑定到了主服务器，如下:

[root@lvs ~]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500inet 192.168.163.144  netmask 255.255.255.0  broadcast 192.168.163.255inet6 fe80::491f:4a6e:f34:a1b9  prefixlen 64  scopeid 0x20<link>ether 00:0c:29:a3:4f:a2  txqueuelen 1000  (Ethernet)RX packets 156094  bytes 70487425 (67.2 MiB)RX errors 0  dropped 0  overruns 0  frame 0TX packets 195001  bytes 16040484 (15.2 MiB)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0ens33:200: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500inet 192.168.163.200  netmask 255.255.255.0  broadcast 192.168.163.255ether 00:0c:29:a3:4f:a2  txqueuelen 1000  (Ethernet)lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536inet 127.0.0.1  netmask 255.0.0.0inet6 ::1  prefixlen 128  scopeid 0x10<host>loop  txqueuelen 1000  (Local Loopback)RX packets 331  bytes 28808 (28.1 KiB)RX errors 0  dropped 0  overruns 0  frame 0TX packets 331  bytes 28808 (28.1 KiB)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0[root@lvs ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags-> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.163.200:80 rr-> 192.168.163.145:80           Route   1      0          0         -> 192.168.163.146:80           Route   1      0          0

3.测试

1.测试负载均衡

[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.145  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.145  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .

2.测试RS高可用

关闭一台RS后(这里可以使用ifconfig 网卡名 down命令暂时关闭网卡)，客户端继续发起请求，查看是否可以正常访问，如下:

[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .

会发现，此时客户端可以正常访问，但只有RS2在提供服务。这说明，keepAlived检测到了RS1服务器异常，将其剔除了。

此时再启动RS1服务器，客户端继续访问，会发现响应结果如下，keepAlived检测到RS1服务器恢复正常，又将其加入服务列表了。

[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.145  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.145  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .

3.测试LVS高可用

这里主要进行两个测试

3.1测试lvs主服务宕机

使用ifconfig 网卡名 down命令，关闭主服务器网卡，此时主服务器不能提供服务。观察备份服务器是否将VIP绑定到自己，以及客户端是否可以继续正常访问。如下：

关闭主服务器网卡

[root@lvs ~]# ifconfig ens33 down

观察备份服务器，会发现VIP已经绑定过来了。这里实际是keepAlived检测到了主服务器的异常，而做出的故障转移和自动切换。

[root@lvs-backup keepalived]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500inet 192.168.163.150  netmask 255.255.255.0  broadcast 192.168.163.255inet6 fe80::94e3:7456:5dc9:ce5d  prefixlen 64  scopeid 0x20<link>inet6 fe80::9aec:8c8f:ee55:a8eb  prefixlen 64  scopeid 0x20<link>ether 00:0c:29:c0:57:db  txqueuelen 1000  (Ethernet)RX packets 43484  bytes 5026535 (4.7 MiB)RX errors 0  dropped 0  overruns 0  frame 0TX packets 12787  bytes 1188939 (1.1 MiB)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0ens33:200: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500inet 192.168.163.200  netmask 255.255.255.0  broadcast 192.168.163.255ether 00:0c:29:c0:57:db  txqueuelen 1000  (Ethernet)lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536inet 127.0.0.1  netmask 255.0.0.0inet6 ::1  prefixlen 128  scopeid 0x10<host>loop  txqueuelen 1000  (Local Loopback)RX packets 0  bytes 0 (0.0 B)RX errors 0  dropped 0  overruns 0  frame 0TX packets 0  bytes 0 (0.0 B)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

用客户进行测试

[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.145  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.145  .
[root@client ~]# curl 192.168.163.200
web1 test, ip is 192.168.163.146  .

3.2.测试lvs主服务器恢复

上述测试通过后，可以开启主服务器网卡，让其能够提供服务，然后观察VIP是否会回到主服务器。

开启主服务器网卡

[root@lvs ~]# ifconfig ens33 up

我们会发现，在主服务器开启端口后，VIP又换绑到主服务器上了

[root@lvs ~]# ifconfig 
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500inet 192.168.163.144  netmask 255.255.255.0  broadcast 192.168.163.255inet6 fe80::491f:4a6e:f34:a1b9  prefixlen 64  scopeid 0x20<link>ether 00:0c:29:a3:4f:a2  txqueuelen 1000  (Ethernet)RX packets 157697  bytes 70649781 (67.3 MiB)RX errors 0  dropped 0  overruns 0  frame 0TX packets 200310  bytes 16401598 (15.6 MiB)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0ens33:200: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500inet 192.168.163.200  netmask 255.255.255.0  broadcast 192.168.163.255ether 00:0c:29:a3:4f:a2  txqueuelen 1000  (Ethernet)lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536inet 127.0.0.1  netmask 255.0.0.0inet6 ::1  prefixlen 128  scopeid 0x10<host>loop  txqueuelen 1000  (Local Loopback)RX packets 331  bytes 28808 (28.1 KiB)RX errors 0  dropped 0  overruns 0  frame 0TX packets 331  bytes 28808 (28.1 KiB)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root@lvs-backup keepalived]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500inet 192.168.163.150  netmask 255.255.255.0  broadcast 192.168.163.255inet6 fe80::94e3:7456:5dc9:ce5d  prefixlen 64  scopeid 0x20<link>inet6 fe80::9aec:8c8f:ee55:a8eb  prefixlen 64  scopeid 0x20<link>ether 00:0c:29:c0:57:db  txqueuelen 1000  (Ethernet)RX packets 43995  bytes 5081851 (4.8 MiB)RX errors 0  dropped 0  overruns 0  frame 0TX packets 13240  bytes 1226592 (1.1 MiB)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536inet 127.0.0.1  netmask 255.0.0.0inet6 ::1  prefixlen 128  scopeid 0x10<host>loop  txqueuelen 1000  (Local Loopback)RX packets 0  bytes 0 (0.0 B)RX errors 0  dropped 0  overruns 0  frame 0TX packets 0  bytes 0 (0.0 B)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0