1.前言
上篇文章我们配置的双机热备,意思是说两台机器一台处于运行中,另一台永久处于备份。这样的话资源浪费严重,适用于国企,政府类系统。今天我们所讲的是双机双主热备,意味着两台机器同时处于工作状态,两台主机又同时为备份状态。
2.准备:
两台主机192.168.100.128/24 192.168.100.129/24
两个单独的ip 192.168.100.133/24 192.168.100.134/24
可以将你域名解析到这两个单独的ip,keepalived会将这两个ip通过虚拟ip技术漂移到两台主机上。如果一台机器down,keepalived会将原本漂移在它身上的ip,漂移到另一台机器上,这样就实现了双机双主互为主机和备份。
3.安装
安装可以查看我的上篇文章:nginx+keepalived实现双机热备高可用性 http://blog.csdn.net/caicongyang/article/details/46444007
4.配置
128机器 keepalived.conf配置文件
global_defs {
notification_email {
1491318829@qq.com
}
notification_email_from keepalived@localhost.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {
script "/opt/nginx_pid.sh"
interval 2
weight -20 #每检查一次,权重减去20
}
vrrp_instance VI_1 {
state MASTER
interface eth1 #注意看到你本机的网络接口
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
192.168.100.133
}
}
vrrp_instance VI_2 {
state BACKUP
interface eth1 #两处都为本机的网络接口
virtual_router_id 52
priority 99 #权重
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.100.134/24
}
}
129机器 keepalived.conf配置文件
global_defs {
notification_email {
1491318829@qq.com #接收警报的email地址,可以添加多个
}
notification_email_from admin@caicongyang.com ###发件人地址
smtp_server 127.0.0.1 ###发送邮件的服务器
smtp_connect_timeout 30 ###超时时间
router_id LVS_DEVEL ####load balancer 的标识 ID,用于email警报
}
vrrp_script chk_http_port {
script "/opt/nginx_pid.sh" ####检测nginx状态的脚本路径
interval 2
weight -20
}
vrrp_instance VI_1 {
state BACKUP
interface eth2
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.100.133/24
}
}
vrrp_instance VI_2 {
state MASTER
interface eth2
virtual_router_id 52
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
192.168.100.134/24
}
}
5.启动和测试
启动nginx
#/usr/local/nginx/sbin/nginx
启动keepalived
#service keepalived start
测试
1: lo: 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: eth1: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:ff:ca:24 brd ff:ff:ff:ff:ff:ff
inet 192.168.100.128/24 brd 192.168.100.255 scope global eth1
inet 192.168.100.133/32 scope global eth1
inet6 fe80::20c:29ff:feff:ca24/64 scope link
valid_lft forever preferred_lft forever
129机器结果
1: lo: 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: eth2: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:c0:02:92 brd ff:ff:ff:ff:ff:ff
inet 192.168.100.129/24 brd 192.168.100.255 scope global eth2
inet 192.168.100.134/24 scope global secondary eth2
inet6 fe80::20c:29ff:fec0:292/64 scope link
valid_lft forever preferred_lft forever
我们可以看到ip 133已经绑定到128的机器上了,134已经绑定到129的机器上了
接下来我们可以利用在128机器killall nginx查看上篇文章中的脚本能否起作用,结果是我们可以看到nginx会不断的重启。
那我们直接关掉128的机器,或者关闭的它的网络,然后看到ip133是否能自动绑定到129的机器上呢?结果当然是可以的
1: lo: 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: eth2: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:c0:02:92 brd ff:ff:ff:ff:ff:ff
inet 192.168.100.129/24 brd 192.168.100.255 scope global eth2
inet 192.168.100.134/24 scope global secondary eth2
inet 192.168.100.133/24 scope global secondary eth2
inet6 fe80::20c:29ff:fec0:292/64 scope link
valid_lft forever preferred_lft forever
如同上篇文章所说的,你可以用一下命令查看整个过程
#tail -f /var/log/messages
后记:这两边nginx+keepalied高可用性的文章中,我们配置了notification_email但是都没用到,楼主将在下篇文章配置smtp服务,让其生效,这样就能在服务发生异常的情况下,发送邮件提醒运维人员。当然博主我也会在后期发布免费网络监视工具Nagios的相关文章,将其整合进来,具体利弊后期分析。
不懂运维的程序员,不是好的工程师!
我的个人网站:http://www.caicongyang.com
我的CSDN博客地址: http://blog.csdn.net/caicongyang