↑构建高可用LVS + keepalived+httpd和双主模型的keepalived方案↑
标签：web服务器 拓扑图 模型 检测 软件
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keepalived简介
keepalived是一个类似于layer3, 4 & 5交换机制的软件，也就是我们平时说的第3层、第4层和第5层交换。Keepalived的作用是检测web服务器的状态，如果有一台web服务器死机，或工作出现故障，Keepalived将检测到，并将有故障的web服务器从系统中剔除，当web服务器工作正常后Keepalived自动将web服务器加入到服务器群中，通过ping来监测对方的状态。
拓扑图：
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实验环境：
centos-6.4
所需的安装包：
主的和备的Director上都安装上keepalived
后端的两个realserver上都安装上htppd服务
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1.先同步个节点上的时间
[root@yulong]# ntpdate 172.16.0.1
2.在主的和从的上面安装keepalived
[root@yulong ~]# yum install keepalived -y
3.编辑keepalived配置文件
[root@yulong keepalived]# vim keepalived.conf
修改一下参数为自己所用的
global_defs {
notification_email {
root@localhost 收件人
}
notification_email_from keep@localhost 发件人
smtp_server 127.0.0.1 邮件服务器
smtp_connect_timeout 10 链接超时时间
router_id LVS_DEVEL
添加如下字段设置可以手动切换故障转移:
vrrp_script chk_maintainace {
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 1
weight -2
}
这段脚本的意思就是如果在这个目录下存在down的这个一个文件就把vip给转移到BAKPUP节点.这个文件可以手动创建来实现调试.
以下用文字注释的都是需要修改的地方
vrrp_instance VI_1 {
state MASTER 设置主节点
interface eth0 网卡类型
virtual_router_id 51 虚拟路由ID
priority 100 设置权重,权重必须大于BACKUP的权重
advert_int 1
authentication {
auth_type PASS 加密方法
auth_pass 1111 密码
}
virtual_ipaddress {
172.16.8.100 设置访问的虚拟IP
}
track_script {
chk_maintainace 这个是定义刚才添加的那段代码生效
}
}
4.配置完毕以上内容后复制到从节点上一份
[root@yulong keepalived]# scp keepalived.conf yu:/etc/keepalived/
5.然后在从节点上需要修改下如下两项
[root@www ~]# vim /etc/keepalived/keepalived.conf
state BACKUP 设置为备用节点
priority 99 权重设置为比主节点的小
6.然后主备都启动keepalived服务
[root@yulong keepalived]# service keepalived restart
Stopping keepalived: [ OK ]
Starting keepalived: [ OK ]
7.然后查看master上的状态
[root@yulong keepalived]# ip addr show
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:0e:d7:4d brd ff:ff:ff:ff:ff:ff
inet 172.16.8.17/16 brd 172.16.255.255 scope global eth0
inet 172.16.8.100/32 scope global eth0 刚才配置的虚拟ip已经生效
inet6 fe80::20c:29ff:fe0e:d74d/64 scope link
valid_lft forever preferred_lft forever
8.然后我们把master上的节点给停掉看看能不能转移
root@yulong keepalived]# touch down
[root@yulong keepalived]# ip addr show
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:0e:d7:4d brd ff:ff:ff:ff:ff:ff
inet 172.16.8.17/16 brd 172.16.255.255 scope global eth0
inet6 fe80::20c:29ff:fe0e:d74d/64 scope link
valid_lft forever preferred_lft forever
在keepalived目录下Touch down 文件是我们写的那条脚本,很强大哟
在次ip addr show查看vip已经没有了
9.在备节点上查看vip有没有转移过来
[root@www ~]# ip addr show
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:6a:51:21 brd ff:ff:ff:ff:ff:ff
inet 172.16.8.18/16 brd 172.16.255.255 scope global eth0
inet 172.16.8.100/32 scope global eth0 OK,已经转移过来了,说明是正常的.
inet6 fe80::20c:29ff:fe6a:5121/64 scope link
valid_lft forever preferred_lft forever
10.下面在主节点上配置keepalived的realserver能调度上游的服务器
[root@yulong keepalived]# vim keepalived.conf
virtual_server 172.16.8.100 80 { 虚拟IP,就是一会要访问的IP
delay_loop 6
lb_algo rr 调度算法
lb_kind DR lvs的模式
nat_mask 255.255.0.0
persistence_timeout 50
protocol TCP 使用的协议
real_server 172.16.8.10 80 { realserver的ip地址 这个别写错了
weight 1 权重
TCP_CHECK { realserver的状态监测
connect_timeout 3 响应超时时间,默认3秒
nb_get_retry 3 重试次数
delay_before_retry 3 重试间隔时间
}
}
real_server 172.16.8.11 80 { 第二个realserver的定义 和上面的一样
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
11.配置完毕以后复制到备服务器上一份
[root@yulong keepalived]# scp keepalived.conf yu:/etc/keepalived/
然后在备的上面编辑keepalived.conf修改如下两项
state BACKUP 设置为备用节点
priority 99 权重设置为比主节点的小
12.上面的配置好以后我们来配置realserver服务器,两个realserver上都配置如下命令
[root@node1 ~]# ifconfig lo:0 172.16.8.100 broadcast 172.16.8.100 netmask 255.255.255.255 up
由于我们使用的DR模型配置DR模型的vip,在lo上配置就行
[root@node1 ~]# echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
[root@node1 ~]# echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
[root@node1 ~]# echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
[root@node1 ~]# echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
关闭arp广播
[root@node1 ~]# echo "<h1> you are word</h1>" > /var/www/html/index.html
设置访问的网页主页内容
13.配置完成后两个realserver服务器上都启动web服务器进行测试
[root@node1 ~]# service httpd restart
Stopping httpd: [ OK ]
Starting httpd: [ OK ]
多点击几下看看是不是均衡
131724243.png
131725953.png
访问成功,看来是均衡的
14.下面我们来通过ipvsadm查看下访问的状态
[root@yulong keepalived]# yum install ipvsadm
[root@yulong keepalived]# ipvsadm -L -n --stats
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Conns InPkts OutPkts InBytes OutBytes
-> RemoteAddress:Port
TCP 172.16.8.100:80 3 3 0 156 0
-> 172.16.8.10:80 2 2 0 104 0
-> 172.16.8.11:80 1 1 0 52 0
Ok 看来是通过keepalived调用的
下面来配置keepalived双主模型
1.在主的上面添加如下内容
[root@yulong keepalived]# vim keepalived.conf
vrrp_instance VI_2 {
state BACKUP
interface eth0
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 2111
}
virtual_ipaddress {
172.16.8.200
}
track_script {
chk_maintainace
}
}
2.在备的上面添加如下内容
vrrp_instance VI_2 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 2111
}
virtual_ipaddress {
172.16.8.200
}
track_script {
chk_maintainace
}
}
3.重启主备的keepalived的服务
[root@yulong keepalived]# service keepalived restart
4.查看备的上面虚拟主ip有木有生效
[root@www ~]# ip addr show
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:6a:51:21 brd ff:ff:ff:ff:ff:ff
inet 172.16.8.18/16 brd 172.16.255.255 scope global eth0
inet 172.16.8.200/32 scope global eth0 已经生效
inet6 fe80::20c:29ff:fe6a:5121/64 scope link
valid_lft forever preferred_lft forever
5.下面我们把备的master给down掉看看是否会转移
root@www ~]# cd /etc/keepalived/
[root@www keepalived]# touch down
[root@www keepalived]# ip addr show
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:6a:51:21 brd ff:ff:ff:ff:ff:ff
inet 172.16.8.18/16 brd 172.16.255.255 scope global eth0
inet6 fe80::20c:29ff:fe6a:5121/64 scope link
valid_lft forever preferred_lft forever
172.16.8.200 的虚拟ip已经看不到了
6.下面在主的上面看看是否转移过来
[root@yulong keepalived]# ip addr show
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:0e:d7:4d brd ff:ff:ff:ff:ff:ff
inet 172.16.8.17/16 brd 172.16.255.255 scope global eth0
inet 172.16.8.100/32 scope global eth0
inet 172.16.8.200/32 scope global eth0
inet6 fe80::20c:29ff:fe0e:d74d/64 scope link
valid_lft forever preferred_lft forever
两个虚拟ip都在,证明是正常的,此次双主模型搞定！
本文转自rshare 51CTO博客，原文链接：http://blog.51cto.com/1364952/1980066，如需转载请自行联系原作者
