Keepalived+LVS-DR模式高可用负载均衡集群的搭建

主机环境 redhat6.5 64位
实验环境 服务端1 ip 172.25.25.113 主机名：server3.example.com
服务端2 ip 172.25.25.114 主机名：server4.example.com
管理端2 ip 172.25.25.112 主机名：server2.example.com
管理端1 ip 172.25.25.111 主机名：server1.example.com
防火墙状态：关闭
虚拟ip（vip）： 172.25.25.200/24

前面的博文中已经介绍过将DR添加到高可用集群（HA）的heartbeat中避免单点故障，本节将介绍将另一个避免单点故障的方法：将DR添加到HA的keepalived中。keepalived对后端有健康检查，则在安装好keepalived之后可直接添加DR。本节将不再介绍DR的配置，感兴趣的可查看前面的博文，本文直接从keeepalived的安装开始。在Keepalived.org官网可下载leepalived压缩包（keeepalived对后端有健康检查）
1.源码安装keepalived
[root@server1 mnt]# ls
keepalived-1.2.24.tar.gz
[root@server1 mnt]# tar zxf keepalived-1.2.24.tar.gz #解压
keepalived-1.2.24
keepalived-1.2.24.tar.gz
[root@server1 mnt]# cd keepalived-1.2.24
[root@server1 keepalived-1.2.24]# ls
aclocal.m4 ChangeLog CONTRIBUTORS genhash keepalived.spec.in missing
ar-lib compile COPYING INSTALL lib README
AUTHOR configure depcomp install-sh Makefile.am TODO
bin_install configure.ac doc keepalived Makefile.in
[root@server1 keepalived-1.2.24]# ./configure--prefix=/usr/local/keepalived
若有以下错误



则安装
[root@server1 keepalived-1.2.24]# yum installopenssl-devel.x86_64 -y
[root@server1 keepalived-1.2.24]# ./configure--prefix=/usr/local/keepalived
[root@server1 keepalived-1.2.24]# make
[root@server1 keepalived-1.2.24]# make install
[root@server1 keepalived-1.2.24]# cd /usr/local/
[root@server1 local]# ls
bin etc games include keepalived lib lib64 libexec sbin share src
[root@server1 local]# scp -r keepalived/172.25.25.112:/usr/local/
root@172.25.25.112's password:
#作软连接
[root@server1 local]# ln -s/usr/local/keepalived/etc/keepalived/ /etc/ #主配置文件的软链接
[root@server1 local]# ln -s/usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/ #启动脚本的软链接
[root@server1 local]# chmod +x /etc/init.d/keepalived #改变脚本的权限
[root@server1 local]# ln -s/usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ #配置文件的软链接
[root@server1 local]# ln -s/usr/local/keepalived/sbin/keepalived /sbin/ #二进制文件的软链接
[root@server1 local]# /etc/init.d/keepalived start #测试，开启
Starting keepalived: [ OK ]
[root@server1 local]# /etc/init.d/keepalived stop
Stopping keepalived: [ OK ]
[root@server1 local]#

2.将DR添加到keepalived及测试（管理端） 1.添加DR到keepalived
[root@server1 local]# cd /etc/keepalived/
[root@server1 keepalived]# ls
keepalived.conf samples
[root@server1 keepalived]# vim keepalived.conf #进入主配置文件
1 ! Configuration Filefor keepalived
2
3 global_defs {
4 notification_email {
5 root@localhost #邮件接受端
6 }
7 notification_email_from keepalived@server1.example.com #邮件发送端
8 smtp_server 127.0.0.1 #本地回环
9 smtp_connect_timeout 30 #连接超时
10 router_id LVS_DEVEL
11 vrrp_skip_check_adv_addr
12 vrrp_strict
13 vrrp_garp_interval 0
14 vrrp_gna_interval 0
15 }
16
17 vrrp_instance VI_1 {
18 state MASTER #服务端1是master
19 interface eth0 #进入接口eth0
20 virtual_router_id 25 #虚拟路由id（1-254之间）
21 priority 100 #在启动keepalived服务时，系统会比较priority的值，哪个值大哪个就是master
22 advert_int 1
23 authentication {
24 auth_type PASS
25 auth_pass 1111
26 }
27 virtual_ipaddress {
28 172.25.25.200 #虚拟ip‘
29 }
30 }
31
32 virtual_server172.25.25.200 80 { #虚拟服务
33 delay_loop 6
34 lb_algo rr
35 lb_kind DR #DR
36 # persistence_timeout 50 #超时
37 protocol TCP
38
39 real_server 172.25.25.113 80 { #真正的服务端
40 weight 1 #权重
41 TCP_CHECK {
42 connect_timeout 3
43 nb_get_retry 3
44 delay_before_retry 3
45 }
46 }
47 real_server 172.25.25.114 80 { #真正的服务端
48 weight 1
49 TCP_CHECK {
50 connect_timeout 3
51 nb_get_retry 3
52 delay_before_retry 3
53 }
54 }
55
56 }
[root@server1 keepalived]# /etc/init.d/keepalived start #开启（服务端1）
Starting keepalived: [ OK ]

[root@server1 keepalived]# scp keepalived.conf172.25.25.112:/etc/keepalived/
root@172.25.25.112's password: #将其传到服务端2
keepalived.conf 100%1049 1.0KB/s 00:00
[root@server2 keepalived]# vim keepalived.conf #进入刚传到服务端2文件，修改
7 notification_email_from keepalived@server2.example.com#邮件发送段，本机
18 state BACKUP #备服务器
2[root@server2 local]# /etc/init.d/keepalived start #开启（服务端2）
Starting keepalived: [ OK ]
1 priority 88 #比主的数值小就可以

2.测试
[root@server1 keepalived]# ipvsadm -l
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
->RemoteAddress:Port ForwardWeight ActiveConn InActConn
TCP 172.25.25.200:httprr
->server3.example.com:http Route 1 0 0
->172.25.25.114:http Route 1 0 0



#刷新之后，服务端2



[root@server1 keepalived]# ip addr show #查看ip，虚拟ip在服务端1
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueuestate UNKNOWN
link/loopback00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8scope host lo
inet6 ::1/128 scopehost
valid_lft foreverpreferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdiscpfifo_fast state UP qlen 1000
link/ether 52:54:00:ec:8b:36brd ff:ff:ff:ff:ff:ff
inet 172.25.25.111/24brd 172.25.25.255 scope global eth0
inet 172.25.25.200/32scope global eth0 #虚拟ip
inet6fe80::5054:ff:feec:8b36/64 scope link
valid_lft foreverpreferred_lft forever

当主机keepalived停掉，系统会将服务转移到备机上；当主机重新打开时，系统会重新读配置文件，来确定主机和备机，将服务开启到主机上

#将服务端1的keepalived停掉，测试
[root@server1 keepalived]# /etc/init.d/keepalived stop
Stopping keepalived: [ OK ]
#服务正常



#刷新之后，服务端2



[root@server1 keepalived]# ip addr show #查看，虚拟ip不在服务端1
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueuestate UNKNOWN
link/loopback00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8scope host lo
inet6 ::1/128 scopehost
valid_lft foreverpreferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdiscpfifo_fast state UP qlen 1000
link/ether52:54:00:ec:8b:36 brd ff:ff:ff:ff:ff:ff
inet 172.25.25.111/24brd 172.25.25.255 scope global eth0
inet6fe80::5054:ff:feec:8b36/64 scope link
valid_lft foreverpreferred_lft forever

[root@server2 keepalived]# ip addr show #查看ip虚拟在服务端2
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueuestate UNKNOWN
link/loopback00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scopehost lo
inet6 ::1/128 scopehost
valid_lft foreverpreferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdiscpfifo_fast state UP qlen 1000
link/ether52:54:00:85:1a:3b brd ff:ff:ff:ff:ff:ff
inet 172.25.25.112/24brd 172.25.25.255 scope global eth0
inet 172.25.25.200/32scope global eth0 #虚拟ip
inet6fe80::5054:ff:fe85:1a3b/64 scope link
valid_lft foreverpreferred_lft forever

#将服务端1的keepalived开启
[root@server1 keepalived]# /etc/init.d/keepalived start
Starting keepalived: [ OK ]
#服务正常运行



#刷新之后，服务端2



[root@server1 keepalived]# ip addr show #查看虚拟ip，回到服务端1
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueuestate UNKNOWN
link/loopback00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8scope host lo
inet6 ::1/128 scopehost
valid_lft foreverpreferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdiscpfifo_fast state UP qlen 1000
link/ether52:54:00:ec:8b:36 brd ff:ff:ff:ff:ff:ff
inet 172.25.25.111/24brd 172.25.25.255 scope global eth0
inet 172.25.25.200/32scope global eth0 #虚拟ip
inet6fe80::5054:ff:feec:8b36/64 scope link
valid_lft foreverpreferred_lft forever
[root@server2 keepalived]# ip addr show #查看，服务端2上没有虚拟ip
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueuestate UNKNOWN
link/loopback00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8scope host lo
inet6 ::1/128 scopehost
valid_lft foreverpreferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdiscpfifo_fast state UP qlen 1000
link/ether52:54:00:85:1a:3b brd ff:ff:ff:ff:ff:ff
inet 172.25.25.112/24brd 172.25.25.255 scope global eth0
inet6fe80::5054:ff:fe85:1a3b/64 scope link
valid_lft foreverpreferred_lft forever