Centos下使用LVS+Keepalived构建高可用linux集群

lvs：LB的实现（负载均衡）

环境：Centos 5.5

前端调度器Director使用主备模式，主的宕机了，备的接手任务

前端调度器1：LVS-master 192.168.220.5

前端调度器2：LVS-backup 192.168.220.6

后端服务器池：web1:192.168.220.11

             web2:192.168.220.12

虚拟VIP：192.168.220.220

一：在LVS-master和 LVS-backup上面分别安装ipvsadm和keepalived

A：安装ipvsadm

1,先要做一个连接文件： ln -s /usr/src/kernels/2.6.18-308.8.1.el5-i686/ /usr/src/linux/

注意：如果ll /usr/src/kernels/ 目录下没东西，则 yum -y install kernel-devel解决

有关编译错误可看官方wiki文档： http://kb.linuxvirtualserver.org/wiki/Compiling_ipvsadm_on_different_Linux_distributions#Compiling_Error_Analysis

2，[root@master ~]# ll
total 332
-rw------- 1 root root 876 Jun 2 14:26 anaconda-ks.cfg
-rw-r--r-- 1 root root 18262 Jun 2 14:26 install.log
-rw-r--r-- 1 root root 3969 Jun 2 14:25 install.log.syslog
-rw-r--r-- 1 root root 36598 Jun 7 2012 ipvsadm-1.24.tar.gz
-rw-r--r-- 1 root root 241437 Jun 7 2012 keepalived-1.1.19.tar.gz
[root@master ~]#tar zxvf ipvsadm-1.24.tar.gz
[root@master ~]# cd ipvsadm-1.24
[root@master ipvsadm-1.24]#make;make install

B:安装keepalived

，[root@master ~]# ll
total 332
-rw------- 1 root root 876 Jun 2 14:26 anaconda-ks.cfg
-rw-r--r-- 1 root root 18262 Jun 2 14:26 install.log
-rw-r--r-- 1 root root 3969 Jun 2 14:25 install.log.syslog
-rw-r--r-- 1 root root 36598 Jun 7 2012 ipvsadm-1.24.tar.gz
-rw-r--r-- 1 root root 241437 Jun 7 2012 keepalived-1.1.19.tar.gz
[root@master ~]#tar zxvf keepalived-1.1.19.tar.gz
[root@master ~]# cd keepalived-1.1.19

[root@master ipvsadm-1.24]#./configure --prefix=/usr/local/keepalived
[root@master ipvsadm-1.24]#make;make install
C:LVS-master上的配置脚本为,vim /usr/local/keepalived/etc/keepalived/keepalived.conf

! Configuration File for keepalived
#全局定义部分
global_defs {
notification_email {
[email protected]#设置邮件报警地址，可以设置多个，每行一个
[email protected]
[email protected]
}
notification_email_from

[email protected]

#设置邮件的发送地址
smtp_server 127.0.0.1 #设置smtp server地址
smtp_connect_timeout 30 #设置连接smtp server的超时时间
router_id LVS_DEVEL #表示运行keepalived服务器的一个标示，发邮件时显示在邮件主题中的信息
}
#vrrp实例定义部分
vrrp_instance VI_1 {
state MASTER #指定keepalived的角色
interface eth0 #指定HA检测网络的端口
virtual_router_id 51 #虚拟路由表示，这个表示是一个数字，同一个vrrp实例使用唯一的标示
priority 100 #定义优先级，数字越大，优先级越大，在同一个vrrp_instance下，MASTER的优先级必须高于BACKUP
advert_int 1 #设定MASTER和BACKUP负载均衡器之间的同步检查的时间间隔，单位是秒
authentication {

auth_type PASS #设定验证类型，主要有PASS和AH两种
auth_pass 1111 #设置密码，在同一个vrrp_instance下，MASTER和BACKUP必须使用相同的密码才能正常通信
}
virtual_ipaddress { #设置虚拟IP地址，可以为多个虚拟IP地址，每行一个
192.168.220.220
}
}
#虚拟服务器定义部分
virtual_server 192.168.220.220 80 { #设置虚拟服务器，需要指定虚拟IP地址和服务器端口，IP与端口之间用空格隔开
delay_loop 6 #设置运行情况检查时间，单位是秒
lb_algo rr #设置负载调度算法，这里是rr,即轮询算法
lb_kind DR #设置LVS 实现负载均衡的调度机制，有NAT 、TUN和DR三个模式
persistence_timeout 1 #会话保持时间，单位是秒
protocol TCP #指定转发协议的类型

real_server 192.168.220.12 80 { #配置web2

weight 100 #服务节点的权值
TCP_CHECK { #realserver的状态检测部分，单位是秒
connect_timeout 3 #表示三秒无响应超时
nb_get_retry 3 #表示重试次数
delay_before_retry 3 #表示重试间隔
connect_port 80 #连接的端口
}
}

real_server 192.168.220.11 80 { #配置web1
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}

}

D:C:LVS-backup上的配置脚本为,vim /usr/local/keepalived/etc/keepalived/keepalived.conf 红色部分为和LVS-master的区别
! 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 BACKUP
interface eth0
virtual_router_id 51
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.220.220
}
}

virtual_server 192.168.220.220 80 {

delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 1
protocol TCP

real_server 192.168.220.12 80 {

weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}

real_server 192.168.220.11 80 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}

二：在后端服务器池realserver上的设置;

A：

web1:192.168.220.11

新建脚本vim /root/lvs-realserver.sh如下：

#!/bin/bash
#description :Start Real Server
VIP=192.168.220.220
/etc/rc.d/init.d/functions
case "$1" in
start)
echo "Start LVS of Real Server"
/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up
echo "1" > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" > /proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" > /proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" > /proc/sys/net/ipv4/conf/all/arp_announce
;;
stop)
/sbin/ifconfig lo:0 down
echo "close LVS Director server"
echo "0" > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo "0" > /proc/sys/net/ipv4/conf/lo/arp_announce
echo "0" > /proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" > /proc/sys/net/ipv4/conf/all/arp_announce
;;
*)
echo "Usage: $0 {start|stop}"
exit 1
esac

B:

web2:192.168.220.12

新建脚本vim /root/lvs-realserver.sh如下：

#!/bin/bash
#description :Start Real Server
VIP=192.168.220.220
/etc/rc.d/init.d/functions
case "$1" in
start)
echo "Start LVS of Real Server"
/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up
echo "1" > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" > /proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" > /proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" > /proc/sys/net/ipv4/conf/all/arp_announce
;;
stop)
/sbin/ifconfig lo:0 down
echo "close LVS Director server"
echo "0" > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo "0" > /proc/sys/net/ipv4/conf/lo/arp_announce
echo "0" > /proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" > /proc/sys/net/ipv4/conf/all/arp_announce
;;
*)
echo "Usage: $0 {start|stop}"
exit 1
esac

三：开启服务并测试；

A:在LVS-master和LVS-backup 上分别 [root@master ]# /usr/local/keepalive/sbin/keepalived -f /usr/local/keepalive/etc/keepalived/keepalived.conf 启动keepalived

B:在后端服务器池web1和web2上分别 执行/root/lvs-realserver.sh start

C:进行测试，看看效果怎么样，我的测试成功...