-------------------------------
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
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模拟LB-Master失效
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模拟DNS-Master失效
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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# ./cnfigureKeepalived configuration------------------------Keepalived version : 1.2.1Compiler : gccCompiler flags : -g -O2Extra Lib : -lpopt -lssl -lcrypto Use IPVS Framework : No //配置出现错误IPVS sync daemon support : NoUse VRRP Framework : YesUse 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# lldrwxr-xr-x. 3 root root 4096 May 24 00:37 keepaliveddrwxr-xr-x. 3 root root 4096 May 24 00:29 rc.ddrwxr-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 defineglobal_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 defineglobal_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: [ OK ]Starting named: [ OK ]# cd /var/named/chroot/etc/# vim named.conf //编辑主配置文档 |

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# vim named.rfc1912.zones //编辑区域声明文件[object Object] |

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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 = 2net.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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# ipvsadmIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConnTCP 192.168.2.200:http rr -> 192.168.2.50:http Route 100 0 4 -> 192.168.2.60:http Route 100 0 4 UDP 192.168.2.100:domain rr -> 192.168.2.30:domain Route 100 0 0 -> 192.168.2.40:domain Route 100 0 0 # ip addr1: 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 forever2: 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 InActConnTCP 192.168.2.200:http rr -> 192.168.2.50:http Route 100 0 0 -> 192.168.2.60:http Route 100 0 0 UDP 192.168.2.100:domain rr -> 192.168.2.30:domain Route 100 0 6 -> 192.168.2.40:domain Route 100 0 6 # ip addr1: 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 forever2: 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
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模拟LB-Master失效
(1)停掉LB-Master的keepalived服务
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# service keepalived stopStopping keepalived: [ OK ]# ipvsadmIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn# ip addr1: 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 forever2: 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 addr1: 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 forever2: 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# ipvsadmIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConnTCP 192.168.2.200:http rr -> 192.168.2.50:http Route 100 0 9 -> 192.168.2.60:http Route 100 0 10 UDP 192.168.2.100: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 stopStopping named: . [ OK ] |
(2)查看LB-Master状态(不断在测试客户端刷新网页)
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# ipvsadmIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConnTCP 192.168.2.200:http rr -> 192.168.2.50:http Route 100 0 13 -> 192.168.2.60:http Route 100 0 14 UDP 192.168.2.100:domain rr -> 192.168.2.40:domain Route 100 0 0 |
(3)查看LB-Backup状态
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# ipvsadmIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConnTCP 192.168.2.200:http rr -> 192.168.2.50:http Route 100 0 0 -> 192.168.2.60:http Route 100 0 0 UDP 192.168.2.100: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.51cto.com/8360868/1417899