Lvs+Keepalived+Bind+web构建高可用负载均衡系统
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一、前言
二、环境
三、配置
1.LB-Master及LB-Backup配置
(1)LB-Master及LB-Backup安装keepalived和ipvsadm
(2)LB-Master的keepalived主配置文档
(3)LB-Backup的keepalived主配置文档
2.DNS-Master及DNS-Backup配置
(1)DNS-Master及DNS-Backup网卡设置
(2)DNS-Master及DNS-Backup安装bind及ARP设置
(3)DNS-Master配置
(4)DNS-Backup配置
3.web1及web2配置
四、测试
五、故障模拟
[*] 模拟LB-Master失效
[*] 模拟DNS-Master失效
[*] 模拟web1失效
-------------------------------
一、前言
这个实验是实现企业高可用负载均衡的web案例，无论Master或Backup宕掉任意一台，业务照常可用。分析拓扑，其中LB-Master负责web的调度，LB-Master负责DNS的调度，实现负载均衡，如果其中一台出现故障，那么web和DNS服务会立即转移到另一台服务器上，DNS分为主辅同步，实现高可用，web在生产环境下页面应该是一致的，为了试验效果，web页面设置不一样，在实际环境下，web后端应架设共享存储，实现web页面的一致性。
二、环境
系统：CentOS6.4 32位 6台
拓扑图：
IP划分：
三、配置
1.LB-Master及LB-Backup配置
(1)LB-Master及LB-Backup安装keepalived和ipvsadm
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# yum groupinstall "Additional Development" //安装开发工具
# yum groupinstall "Development tools"
# tar -zxvf keepalived-1.2.1.tar.gz -C /usr/local/src/
# cd /usr/local/src/keepalived-1.2.1
# ./cnfigure
Keepalived configuration
------------------------
Keepalived version : 1.2.1
Compiler : gcc
Compiler flags : -g -O2
Extra Lib : -lpopt -lssl -lcrypto
Use IPVS Framework : No //配置出现错误
IPVS sync daemon support : No
Use VRRP Framework : Yes
Use Debug flags : No
解决方法：
# yum install kernel-devel ipvsadm
# ln -s /usr/src/kernels/2.6.32-358.el6.i686/ /usr/src/linux
# ./cnfigure //再次配置环境
# make //编译
# make install //安装
# cd /usr/local/etc //keepalived默认安装路径
# ll
drwxr-xr-x. 3 root root 4096 May 24 00:37 keepalived
drwxr-xr-x. 3 root root 4096 May 24 00:29 rc.d
drwxr-xr-x. 2 root root 4096 May 24 00:29 sysconfig
配置以系统方式service启动
# cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
# cp /usr/local/etc/sysconfig/keepalived/etc/sysconfig/
# mkdir /etc/keepalived
# cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
# cp /usr/local/sbin/keepalived /usr/sbin/
(2)LB-Master的keepalived主配置文档
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# cat /etc/keepalived/keepalived.conf
#guration File for keepalived
#global define
global_defs {
router_id Haweb_1
}
vrrp_sync_group VGM {
group {
VI_WEB
}
}
vrrp_sync_group VGN {
group {
HA_DNS
}
}
# vvrp_instance define #
vrrp_instance VI_WEB {
state MASTER
interface eth0
lvs_sync_daemon_inteface eth0
virtual_router_id 55
priority 100
advert_int 5
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.2.200/24 dev eth0
}
}
##########LVS###########
virtual_server 192.168.2.200 80 {
delay_loop 6
lb_algo rr
lb_kind DR
# persistence_timeout 20
protocol TCP
real_server 192.168.2.50 80 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
real_server 192.168.2.60 80 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
### HA DNS START ###
vrrp_instance HA_DNS {
state BACKUP
interface eth0
lvs_sync_daemon_inteface eth0
virtual_router_id 56
priority 90
advert_int 5
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.2.100/24 dev eth0
}
}
##########LVS DNS###########
virtual_server 192.168.2.100 53 {
delay_loop 6
lb_algo rr
lb_kind DR
# persistence_timeout 6
protocol UDP
real_server 192.168.2.30 53 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 53
}
}
real_server 192.168.2.40 53 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 53
}
}
}
##################################
(3)LB-Backup的keepalived主配置文档
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# cat /etc/keepalived/keepalived.conf
#guration File for keepalived
#global define
global_defs {
router_id Haweb_1
}
vrrp_sync_group VGM {
group {
VI_WEB
}
}
vrrp_sync_group VGN {
group {
HA_DNS
}
}
# vvrp_instance define #
vrrp_instance VI_WEB {
state BACKUP
interface eth0
lvs_sync_daemon_inteface eth0
virtual_router_id 55
priority 90
advert_int 5
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.2.200/24 dev eth0
}
}
##########LVS###########
virtual_server 192.168.2.200 80 {
delay_loop 6
lb_algo rr
lb_kind DR
# persistence_timeout 20
protocol TCP
real_server 192.168.2.50 80 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
real_server 192.168.2.60 80 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
### HA DNS START ###
vrrp_instance HA_DNS {
state MASTER
interface eth0
lvs_sync_daemon_inteface eth0
virtual_router_id 56
priority 100
advert_int 5
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.2.100/24 dev eth0
}
}
##########LVS DNS###########
virtual_server 192.168.2.100 53 {
delay_loop 6
lb_algo rr
lb_kind DR
# persistence_timeout 6
protocol UDP
real_server 192.168.2.30 53 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 53
}
}
real_server 192.168.2.40 53 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 53
}
}
}
##################################
2.DNS-Master及DNS-Backup配置
(1)DNS-Master及DNS-Backup网卡设置
DNS-Master及DNS-Backup在各自网卡基础上再添加lo:0端口。
(2)DNS-Master及DNS-Backup安装bind及ARP设置
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# yum install bind bind-chroot
# vim /etc/sysctl.conf //添加以下两行
net.ipv4.conf.all.arp_announce = 2 //关闭所有接口的ARP响应和发布
net.ipv4.conf.all.arp_ignore = 1
# sysctl -p (3)DNS-Master配置
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# service named start
Generating /etc/rndc.key:
Starting named:
# cd /var/named/chroot/etc/
# vimnamed.conf //编辑主配置文档
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# vimnamed.rfc1912.zones //编辑区域声明文件
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# scp named.conf named.rfc1912.zones 192.168.2.40:/var/named/chroot/etc/
# cd /var/named/chroot/var/named/
# cp -p named.localhost abc.com.zone
# cp -p named.localhost abc.com.local
# vim abc.com.zone
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# vim abc.com.local
(4)DNS-Backup配置
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# cd /var/named/chroot/etc/
# chgrp named named.conf named.rfc1912.zones
# vim named.rfc1912.zones
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# service named start
# cd /var/named/chroot/var/named/slaves
# ll //区域文件已经同步
-rw-r--r--. 1 named named 325 May 27 19:31 abc.com.local
-rw-r--r--. 1 named named 340 May 27 19:39 abc.com.zone
# vim abc.com.zone
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# vim abc.com.local
3.web1及web2配置
在原有网卡基础上再添加一块lo:0网卡
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# yum install httpd
# echo "This is web1.">/var/www/html/index.html //web1配置
# echo "This is web2.">/var/www/html/index.html //web2配置
# vim /etc/sysctl.conf //添加以下两行
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1
# sysctl -p
# service httpd start 四、测试：
测试客户端IP配置：
客户端浏览器访问http://www.abc.com,并不断刷新，可以看出web1和web2交替不断出现，在实际生产环境下web内容是一样的 。
LB-Master（负责web轮询）：
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# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP192.168.2.200:http rr
-> 192.168.2.50:http Route 100 0 4
-> 192.168.2.60:http Route 100 0 4
UDP192.168.2.100:domain rr
-> 192.168.2.30:domain Route 100 0 0
-> 192.168.2.40:domain Route 100 0 0
# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 00:0c:29:1c:d4:8d brd ff:ff:ff:ff:ff:ff
inet 192.168.2.10/24 brd 192.168.2.255 scope global eth0
inet 192.168.2.200/24 scope global secondary eth0
inet6 fe80::20c:29ff:fe1c:d48d/64 scope link
valid_lft forever preferred_lft forever
LB-Backup（负责DNS轮询）：
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IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP192.168.2.200:http rr
-> 192.168.2.50:http Route 100 0 0
-> 192.168.2.60:http Route 100 0 0
UDP192.168.2.100:domain rr
-> 192.168.2.30:domain Route 100 0 6
-> 192.168.2.40:domain Route 100 0 6
# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 00:0c:29:22:3d:01 brd ff:ff:ff:ff:ff:ff
inet 192.168.2.20/24 brd 192.168.2.255 scope global eth0
inet 192.168.2.100/24 scope global secondary eth0
inet6 fe80::20c:29ff:fe22:3d01/64 scope link
valid_lft forever preferred_lft forever
五、故障模拟
[*] 模拟LB-Master失效
（1）停掉LB-Master的keepalived服务
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# service keepalived stop
Stopping keepalived:
# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 00:0c:29:1c:d4:8d brd ff:ff:ff:ff:ff:ff
inet 192.168.2.10/24 brd 192.168.2.255 scope global eth0
inet6 fe80::20c:29ff:fe1c:d48d/64 scope link
valid_lft forever preferred_lft forever （2）查看LB-Backup状态（不断在测试客户端刷新网页）
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# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 00:0c:29:22:3d:01 brd ff:ff:ff:ff:ff:ff
inet 192.168.2.20/24 brd 192.168.2.255 scope global eth0
inet 192.168.2.100/24 scope global secondary eth0
inet 192.168.2.200/24 scope global secondary eth0
inet6 fe80::20c:29ff:fe22:3d01/64 scope link
valid_lft forever preferred_lft forever
# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP192.168.2.200:http rr
-> 192.168.2.50:http Route 100 0 9
-> 192.168.2.60:http Route 100 0 10
UDP192.168.2.100:domain rr
-> 192.168.2.30:domain Route 100 0 6
-> 192.168.2.40:domain Route 100 0 6 2.模拟DNS-Master失效
（1）停掉DNS-Master的named服务，并恢复LB-Master的服务
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# service named stop
Stopping named: . （2）查看LB-Master状态（不断在测试客户端刷新网页）
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# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP192.168.2.200:http rr
-> 192.168.2.50:http Route 100 0 13
-> 192.168.2.60:http Route 100 0 14
UDP192.168.2.100:domain rr
-> 192.168.2.40:domain Route 100 0 0 （3）查看LB-Backup状态
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# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP192.168.2.200:http rr
-> 192.168.2.50:http Route 100 0 0
-> 192.168.2.60:http Route 100 0 0
UDP192.168.2.100:domain rr
-> 192.168.2.40:domain Route 100 0 6 3.模拟web1失效
停掉web1的httpd服务即可测试，这步比较简单，不再赘述。
本文出自 “一诺千金” 博客，请务必保留此出处http://hatech.blog.iyunv.com/8360868/1417899
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