keepalived+LVS/DR HA负载均衡部署

LVS是一种负载均衡集群；属于四层负载均衡，处理高并发非常有优势；但是LVS本身不具备监控故障点、剔除、添加的功能。我们可以将keepalived+LVS的形式，达到可以自动工作的目的；

我们选用两台主机作为keepalived+LVS服务器；两台运行httpd服务进行测试；

我们先准备集群服务器；

安装ipvsadm；

[root@sxb-1 ~]# yum install ipvsadm

配置keepalive文件；

virtual_server 192.168.88.230 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
   # persistence_timeout 50     #端口亲缘性
    protocol TCP

    real_server 192.168.88.102 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
        }
        }
    real_server 192.168.88.103 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
        }

    }
}

开启转发功能；（两台keepalive都需要开启）

[root@sxb-1 ~]# echo 1 > /proc/sys/net/ipv4/ip_forward

启动 keepalived服务；

[root@sxb-1 ~]# systemctl start keepalived.service

httpd配置；103也需要进行ip的配置；

[root@sxb-2 ~]# ip addr add 192.168.88.230 dev lo
[root@sxb-2 ~]# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet 192.168.88.230/32 scope global lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever

我们还需要修改两个参数；（都需要修改）

[root@sxb-2 ~]# echo 1 > /proc/sys/net/ipv4/conf/ens33/arp_ignore          不作答
[root@sxb-2 ~]# echo 2 > /proc/sys/net/ipv4/conf/ens33/arp_announce　　　　　帮兄弟转发

测试：

我们可以看到浮动IP和LVS策略自动生成了；

[root@sxb-1 ~]# ip addr s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:88:9d:40 brd ff:ff:ff:ff:ff:ff
    inet 192.168.88.101/24 brd 192.168.88.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.88.230/24 scope global secondary ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe88:9d40/64 scope link 
       valid_lft forever preferred_lft forever
[root@sxb-1 ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.88.230:80 rr
  -> 192.168.88.102:80            Masq    1      0          0         
  -> 192.168.88.103:80            Masq    1      0          0 

[root@sxb-5 ~]# curl 192.168.88.230
103
[root@sxb-5 ~]# curl 192.168.88.230
102
[root@sxb-5 ~]# curl 192.168.88.230
103
[root@sxb-5 ~]# curl 192.168.88.230
102

[root@sxb-1 ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.88.230:80 rr
  -> 192.168.88.102:80            Route   1      0          2         
  -> 192.168.88.103:80            Route   1      0          2   

我们停掉master；发现浮动IP消失了

[root@sxb-1 ~]# systemctl stop keepalived.service
[root@sxb-1 ~]# ip addr s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:88:9d:40 brd ff:ff:ff:ff:ff:ff
    inet 192.168.88.101/24 brd 192.168.88.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe88:9d40/64 scope link 
       valid_lft forever preferred_lft forever

keepalived将fudongIP给了104；

[root@sxb-4 ~]# ip addr s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:5b:71:db brd ff:ff:ff:ff:ff:ff
    inet 192.168.88.104/24 brd 192.168.88.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.88.230/24 scope global secondary ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe5b:71db/64 scope link 
       valid_lft forever preferred_lft forever

对于httpd服务器来说没有影响；

[root@sxb-5 ~]# curl 192.168.88.230
103
[root@sxb-5 ~]# curl 192.168.88.230
102
[root@sxb-5 ~]# curl 192.168.88.230
103
[root@sxb-5 ~]# curl 192.168.88.230
102

当master恢复后，依然会出现抢夺问题（王者归来）；具体问题具体对待是否需要抢夺；