keepalived + lvs高可用web服务

xiaoxiao2021-04-18 70

参考文件：http://freeloda.blog.51cto.com/2033581/1280962

大纲

一、前言

二、Keepalived 详解

三、环境准备

四、LVS+Keepalived 实现高可用的前端负载均衡器

一、前言

这篇文章是前几篇文章的总结，我们先简单的总结一下我们前面讲解的内容，前面我们讲解了，LVS（负载均衡器）、Heartbeat、Corosync、Pacemaker、Web高可用集群、MySQL高可用集群、DRDB、iscsi、gfs2、cLVM等，唯一没有讲解的就是LVS可用，也就是前端高可用，我们这一篇博文主要讲解内容。在说这个之前我们得和大家讨论一个问题，也是好多博友问的问题。Heartbeat、Corosync、Keepalived这三个集群组件我们到底选哪个好，首先我想说明的是，Heartbeat、Corosync是属于同一类型，Keepalived与Heartbeat、Corosync，根本不是同一类型的。Keepalived使用的vrrp协议方式，虚拟路由冗余协议 (Virtual Router Redundancy Protocol，简称VRRP)；Heartbeat或Corosync是基于主机或网络服务的高可用方式；简单的说就是，Keepalived的目的是模拟路由器的高可用，Heartbeat或Corosync的目的是实现Service的高可用。所以一般Keepalived是实现前端高可用，常用的前端高可用的组合有，就是我们常见的LVS+Keepalived、Nginx+Keepalived、HAproxy+Keepalived。而Heartbeat或Corosync是实现服务的高可用，常见的组合有Heartbeat v3(Corosync)+Pacemaker+NFS+Httpd 实现Web服务器的高可用、Heartbeat v3(Corosync)+Pacemaker+NFS+MySQL 实现MySQL服务器的高可用。总结一下，Keepalived中实现轻量级的高可用，一般用于前端高可用，且不需要共享存储，一般常用于两个节点的高可用。而Heartbeat(或Corosync)一般用于服务的高可用，且需要共享存储，一般用于多节点的高可用。这个问题我们说明白了，又有博友会问了，那heartbaet与corosync我们又应该选择哪个好啊，我想说我们一般用corosync，因为corosync的运行机制更优于heartbeat，就连从heartbeat分离出来的pacemaker都说在以后的开发当中更倾向于corosync，所以现在corosync+pacemaker是最佳组合。但说实话我对于软件没有任何倾向性，所以我把所有的集群软件都和大家说了一下，我认为不管什么软件，只要它能存活下来都有它的特点和应用领域，只有把特定的软件放在特定的位置才能发挥最大的作用，那首先我们得对这个软件有所有了解。学习一种软件的最好方法，就是去查官方文档。好了说了那么多希望大家有所收获，下面我们来说一说keepalived。

二、Keepalived 详解

1.Keepalived 定义

Keepalived 是一个基于VRRP协议来实现的LVS服务高可用方案，可以利用其来避免单点故障。一个LVS服务会有2台服务器运行Keepalived，一台为主服务器（MASTER），一台为备份服务器（BACKUP），但是对外表现为一个虚拟IP，主服务器会发送特定的消息给备份服务器，当备份服务器收不到这个消息的时候，即主服务器宕机的时候，备份服务器就会接管虚拟IP，继续提供服务，从而保证了高可用性。Keepalived是VRRP的完美实现，因此在介绍keepalived之前，先介绍一下VRRP的原理。

2.VRRP 协议简介

在现实的网络环境中，两台需要通信的主机大多数情况下并没有直接的物理连接。对于这样的情况，它们之间路由怎样选择？主机如何选定到达目的主机的下一跳路由，这个问题通常的解决方法有二种：

在主机上使用动态路由协议(RIP、OSPF等)

在主机上配置静态路由

很明显，在主机上配置动态路由是非常不切实际的，因为管理、维护成本以及是否支持等诸多问题。配置静态路由就变得十分流行，但路由器(或者说默认网关default gateway)却经常成为单点故障。VRRP的目的就是为了解决静态路由单点故障问题，VRRP通过一竞选(election)协议来动态的将路由任务交给LAN中虚拟路由器中的某台VRRP路由器。

3.VRRP 工作机制

在一个VRRP虚拟路由器中，有多台物理的VRRP路由器，但是这多台的物理的机器并不能同时工作，而是由一台称为MASTER的负责路由工作，其它的都是BACKUP，MASTER并非一成不变，VRRP让每个VRRP路由器参与竞选，最终获胜的就是MASTER。MASTER拥有一些特权，比如，拥有虚拟路由器的IP地址，我们的主机就是用这个IP地址作为静态路由的。拥有特权的MASTER要负责转发发送给网关地址的包和响应ARP请求。

VRRP通过竞选协议来实现虚拟路由器的功能，所有的协议报文都是通过IP多播(multicast)包(多播地址224.0.0.18)形式发送的。虚拟路由器由VRID(范围0-255)和一组IP地址组成，对外表现为一个周知的MAC地址。所以，在一个虚拟路由器中，不管谁是MASTER，对外都是相同的MAC和IP(称之为VIP)。客户端主机并不需要因为MASTER的改变而修改自己的路由配置，对客户端来说，这种主从的切换是透明的。

在一个虚拟路由器中，只有作为MASTER的VRRP路由器会一直发送VRRP通告信息(VRRPAdvertisement message)，BACKUP不会抢占MASTER，除非它的优先级(priority)更高。当MASTER不可用时(BACKUP收不到通告信息)，多台BACKUP中优先级最高的这台会被抢占为MASTER。这种抢占是非常快速的(<1s)，以保证服务的连续性。由于安全性考虑，VRRP包使用了加密协议进行加密。

4.VRRP 工作流程

(1).初始化：路由器启动时，如果路由器的优先级是255(最高优先级，路由器拥有路由器地址)，要发送VRRP通告信息，并发送广播ARP信息通告路由器IP地址对应的MAC地址为路由虚拟MAC，设置通告信息定时器准备定时发送VRRP通告信息，转为MASTER状态；否则进入BACKUP状态，设置定时器检查定时检查是否收到MASTER的通告信息。

(2).Master

设置定时通告定时器；

用VRRP虚拟MAC地址响应路由器IP地址的ARP请求；

转发目的MAC是VRRP虚拟MAC的数据包；

如果是虚拟路由器IP的拥有者，将接受目的地址是虚拟路由器IP的数据包，否则丢弃；

当收到shutdown的事件时删除定时通告定时器，发送优先权级为0的通告包，转初始化状态；

如果定时通告定时器超时时，发送VRRP通告信息；

收到VRRP通告信息时，如果优先权为0，发送VRRP通告信息；否则判断数据的优先级是否高于本机，或相等而且实际IP地址大于本地实际IP，设置定时通告定时器，复位主机超时定时器，转BACKUP状态；否则的话，丢弃该通告包；

(3).Backup

设置主机超时定时器；

不能响应针对虚拟路由器IP的ARP请求信息；

丢弃所有目的MAC地址是虚拟路由器MAC地址的数据包；

不接受目的是虚拟路由器IP的所有数据包；

当收到shutdown的事件时删除主机超时定时器，转初始化状态；

主机超时定时器超时的时候，发送VRRP通告信息，广播ARP地址信息，转MASTER状态；

收到VRRP通告信息时，如果优先权为0，表示进入MASTER选举；否则判断数据的优先级是否高于本机，如果高的话承认MASTER有效，复位主机超时定时器；否则的话，丢弃该通告包；

5.ARP查询处理

当内部主机通过ARP查询虚拟路由器IP地址对应的MAC地址时，MASTER路由器回复的MAC地址为虚拟的VRRP的MAC地址，而不是实际网卡的 MAC地址，这样在路由器切换时让内网机器觉察不到；而在路由器重新启动时，不能主动发送本机网卡的实际MAC地址。如果虚拟路由器开启的ARP代理 (proxy_arp)功能，代理的ARP回应也回应VRRP虚拟MAC地址；好了VRRP的简单讲解就到这里，我们下来讲解一下Keepalived的案例。

三、环境准备

1.操作系统

CentOS 6.4 X86_64

2.软件版本

ipvsadm.x86_64 0:1.25-10.el6

keepalived.x86_64 0:1.2.7-3.el6

httpd-2.2.15-29.el6.centos.x86_64

3.实验拓扑

4.时间同步

node1:

1 [root@node1 ~] # ntpdate 202.120.2.101

node2:

1 [root@node2 ~] # ntpdate 202.120.2.101

master:

1 [root@master ~] # ntpdate 202.120.2.101

slave:

1 [root@slave ~] # ntpdate 202.120.2.101

5.主机名互相解析

node1:

1 2 3 4 5 [root@node1 ~] # cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.18.201 node1. test .com node1 192.168.18.202 node2. test .com node2

node2:

1 2 3 4 5 [root@node2 ~] # cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.18.201 node1. test .com node1 192.168.18.202 node2. test .com node2

6.安装yum源

node1:

1 2 [root@node1 ~] # rpm -ivh http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm [root@node1 ~] # rpm -ivh http://elrepo.org/elrepo-release-6-5.el6.elrepo.noarch.rpm

node2:

1 2 [root@node2 ~] # rpm -ivh http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm [root@node2 ~] # rpm -ivh http://elrepo.org/elrepo-release-6-5.el6.elrepo.noarch.rpm

master:

1 2 [root@master ~] # rpm -ivh http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm [root@master ~] # rpm -ivh http://elrepo.org/elrepo-release-6-5.el6.elrepo.noarch.rpm

slave:

1 2 [root@slave ~] # rpm -ivh http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm [root@slave ~] # rpm -ivh http://elrepo.org/elrepo-release-6-5.el6.elrepo.noarch.rpm

四、LVS+Keepalived 实现高可用的前端负载均衡器

node1:

1.安装httpd

1 [root@node1 ~] # yum install -y httpd

2.配置httpd

1 2 [root@node1 ~] # vim /var/www/html/index.html <h1>RS1. test .com< /h1 >

3.启动httpd

1 [root@node1 ~] # service httpd start

4.测试

5.设置开机自启动

1 2 3 [root@node1 ~] # chkconfig httpd on [root@node1 ~] # chkconfig httpd --list httpd 0:关闭 1:关闭 2:启用 3:启用 4:启用 5:启用 6:关闭

6.配置node1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 [root@node1 ~] # mkdir src [root@node1 ~] # cd src/ [root@node1 src] # vim realserver.sh #!/bin/bash # # Script to start LVS DR real server. # description: LVS DR real server # . /etc/rc .d /init .d /functions VIP=192.168.18.200 #修改你的VIP host=` /bin/hostname ` case "$1" in start) # Start LVS-DR real server on this machine. /sbin/ifconfig lo down /sbin/ifconfig lo 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 /sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up /sbin/route add -host $VIP dev lo:0 ;; stop) # Stop LVS-DR real server loopback device(s). /sbin/ifconfig lo:0 down 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 ;; status) # Status of LVS-DR real server. islothere=` /sbin/ifconfig lo:0 | grep $VIP` isrothere=` netstat -rn | grep "lo:0" | grep $VIP` if [ ! "$islothere" -o ! "isrothere" ]; then # Either the route or the lo:0 device # not found. echo "LVS-DR real server Stopped." else echo "LVS-DR real server Running." fi ;; *) # Invalid entry. echo "$0: Usage: $0 {start|status|stop}" exit 1 ;; esac [root@node1 src] # chmod +x realserver.sh [root@node1 src] # ll 总用量 4 -rwxr-xr-x 1 root root 1485 8月 22 10:18 realserver.sh [root@node1 src] # ./realserver.sh start

7.查看配置

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 [root@node1 src] # ifconfig eth0 Link encap:Ethernet HWaddr 00:0C:29:11:92:E4 inet addr:192.168.18.201 Bcast:192.168.18.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe11:92e4 /64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:115061 errors:0 dropped:0 overruns:0 frame:0 TX packets:14979 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:43448483 (41.4 MiB) TX bytes:1224926 (1.1 MiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1 /128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:2 errors:0 dropped:0 overruns:0 frame:0 TX packets:2 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:168 (168.0 b) TX bytes:168 (168.0 b) lo:0 Link encap:Local Loopback inet addr:192.168.18.200 Mask:255.255.255.255 UP LOOPBACK RUNNING MTU:16436 Metric:1 [root@node1 src] # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.18.200 0.0.0.0 255.255.255.255 UH 0 0 0 lo 192.168.18.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0 0.0.0.0 192.168.18.254 0.0.0.0 UG 0 0 0 eth0 [root@node1 src] # cat /proc/sys/net/ipv4/conf/lo/arp_ignore 1 [root@node1 src] # cat /proc/sys/net/ipv4/conf/lo/arp_announce 2 [root@node1 src] # cat /proc/sys/net/ipv4/conf/all/arp_ignore 1 [root@node1 src] # cat /proc/sys/net/ipv4/conf/all/arp_announce 2

好了，node1到这里基本配置完成，下面我们来配置node2。

node2:

1.安装httpd

1 [root@node2 ~] # yum install -y httpd

2.配置httpd

1 2 [root@node2 ~] # vim /var/www/html/index.html <h1>RS2. test .com< /h1 >

3.启动httpd

1 [root@node2 ~] # service httpd start

4.测试

5.设置开机自启动

1 2 3 [root@node2 ~] # chkconfig httpd on [root@node2 ~] # chkconfig httpd --list httpd 0:关闭 1:关闭 2:启用 3:启用 4:启用 5:启用 6:关闭

6.配置node2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 [root@node2 ~] # mkdir src [root@node2 ~] # cd src/ [root@node2 src] # vim realserver.sh #!/bin/bash # # Script to start LVS DR real server. # description: LVS DR real server # . /etc/rc .d /init .d /functions VIP=192.168.18.200 host=` /bin/hostname ` case "$1" in start) # Start LVS-DR real server on this machine. /sbin/ifconfig lo down /sbin/ifconfig lo 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 /sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up /sbin/route add -host $VIP dev lo:0 ;; stop) # Stop LVS-DR real server loopback device(s). /sbin/ifconfig lo:0 down 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 ;; status) # Status of LVS-DR real server. islothere=` /sbin/ifconfig lo:0 | grep $VIP` isrothere=` netstat -rn | grep "lo:0" | grep $VIP` if [ ! "$islothere" -o ! "isrothere" ]; then # Either the route or the lo:0 device # not found. echo "LVS-DR real server Stopped." else echo "LVS-DR real server Running." fi ;; *) # Invalid entry. echo "$0: Usage: $0 {start|status|stop}" exit 1 ;; esac [root@node2 src] # chmod +x realserver.sh [root@node2 src] # ./realserver.sh start

7.查看配置

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 [root@node2 src] # ifconfig eth0 Link encap:Ethernet HWaddr 00:0C:29:B8:DF:6A inet addr:192.168.18.202 Bcast:192.168.18.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:feb8:df6a /64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:110545 errors:0 dropped:0 overruns:0 frame:0 TX packets:10461 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:32853789 (31.3 MiB) TX bytes:889109 (868.2 KiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1 /128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:6 errors:0 dropped:0 overruns:0 frame:0 TX packets:6 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:616 (616.0 b) TX bytes:616 (616.0 b) lo:0 Link encap:Local Loopback inet addr:192.168.18.200 Mask:255.255.255.255 UP LOOPBACK RUNNING MTU:16436 Metric:1 [root@node2 src] # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.18.200 0.0.0.0 255.255.255.255 UH 0 0 0 lo 192.168.18.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0 0.0.0.0 192.168.18.254 0.0.0.0 UG 0 0 0 eth0 [root@node2 src] # cat /proc/sys/net/ipv4/conf/lo/arp_ignore 1 [root@node2 src] # cat /proc/sys/net/ipv4/conf/lo/arp_announce 2 [root@node2 src] # cat /proc/sys/net/ipv4/conf/all/arp_ignore 1 [root@node2 src] # cat /proc/sys/net/ipv4/conf/all/arp_announce 2

好了，到这里node2也基本配置完成。下面我们来配置master与slave。

masterg与slave:

1.安装keepalived与ipvsadm

1 2 [root@master ~] # yum install -y keepalived ipvsadm [root@slave ~] # yum install -y keepalived ipvsadm

2.修改配置文件

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 [root@master ~] # cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 15251076067@163.com #配置管理员邮箱 } notification_email_from root #配置发件人 smtp_server 127.0.0.1 #配置邮件服务器 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state MASTER #配置模式 interface eth0 virtual_router_id 51 priority 101 #配置优先级 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.18.200 #配置虚拟IP地址 } } virtual_server 192.168.18.200 80 { delay_loop 6 lb_algo rr lb_kind DR nat_mask 255.255.255.0 #persistence_timeout 50 protocol TCP real_server 192.168.18.201 80 { #配置realaserver weight 1 HTTP_GET { #监控配置 url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } real_server 192.168.18.202 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } }

3.将配置文件同步到slave

1 [root@master ~] # scp /etc/keepalived/keepalived.conf root@192.168.18.207:/etc/keepalived/

4.简单修改一下slave配置文件

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 [root@slave keepalived] # cat keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 15251076067@163.com } notification_email_from root smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state BACKUP #修改为BACKUP interface eth0 virtual_router_id 51 priority 100 #修改优先级 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.18.200 } } virtual_server 192.168.18.200 80 { delay_loop 6 lb_algo rr lb_kind DR nat_mask 255.255.255.0 #persistence_timeout 50 protocol TCP real_server 192.168.18.201 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } real_server 192.168.18.202 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } }

5.启动master与slave的keepalived服务

1 2 3 4 [root@master ~] # service keepalived start 正在启动 keepalived： [确定] [root@slave ~] # service keepalived start 正在启动 keepalived： [确定]

6.查看一下LVS状态

1 2 3 4 5 6 7 [root@master ~] # ipvsadm -L -n IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 192.168.18.200:80 rr -> 192.168.18.201:80 Route 1 0 0 -> 192.168.18.202:80 Route 1 0 0

7.测试

8.模拟故障

(1).停止一下node1

1 2 [root@node1 src] # service httpd stop 停止 httpd： [确定]

(2).查看一下的lvs

1 2 3 4 5 6 [root@master ~] # ipvsadm -L -n IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 192.168.18.200:80 rr -> 192.168.18.202:80 Route 1 0 0

(3).测试一下

(4).查看一下邮件

(5).重新启动一下node1

1 2 [root@node1 src] # service httpd start 正在启动 httpd： [确定]

(6).再查看一下lvs状态

(7).再查看一下邮件

(8).关闭master上keepalived

1 2 3 4 5 6 [root@master ~] # service keepalived stop 停止 keepalived： [确定] [root@master ~] # ipvsadm -L -n IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn

(9).查看一下slave状态

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 [root@slave ~] # ip addr show 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 UP qlen 1000 link /ether 00:0c:29:f9:e6:26 brd ff:ff:ff:ff:ff:ff inet 192.168.18.207 /24 brd 192.168.18.255 scope global eth0 inet 192.168.18.200 /32 scope global eth0 inet6 fe80::20c:29ff:fef9:e626 /64 scope link valid_lft forever preferred_lft forever [root@slave ~] # ipvsadm -L -n IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 192.168.18.200:80 rr -> 192.168.18.201:80 Route 1 0 0 -> 192.168.18.202:80 Route 1 0 0

(10).再次测试一下

注，大家可以看到，经过上面的演示我们现在LVS的高可用即前端负载均衡的高可用，同时实现对后端realserver监控，也实现后端realserver宕机时会给管理员发送邮件。但还有几个问题我们还没有解决，问题如下:

所有realserver都down机，怎么处理？是不是用户就没法打开，还是提供一下维护页面。

怎么完成维护模式keepalived切换？

如何在keepalived故障时，发送警告邮件给指定的管理员？

9.所有realserver都down机，怎么处理？

问题：在集群中如果所有real server全部宕机了，客户端访问时就会出现错误页面，这样是很不友好的，我们得提供一个维护页面来提醒用户，服务器正在维护，什么时间可以访问等，下面我们就来解决一下这个问题。解决方案有两种，一种是提供一台备用的real server当所有的服务器宕机时，提供维护页面，但这样做有点浪费服务器。另一种就是在负载均衡器上提供维护页面，这样是比较靠谱的，也比较常用。下面我们就来具体操作一下。

(1).master与slave安装上httpd

1 2 [root@master ~] # yum install -y httpd [root@slave ~] # yum install -y httpd

(2).配置维护页面

1 2 3 4 [root@master ~] # vim /var/www/html/index.html Website is currently under maintenance, please come back later! [root@slave ~] # vim /var/www/html/index.html Website is currently under maintenance, please come back later!

(3).启动httpd服务并测试

1 2 3 4 [root@master ~] # service httpd start 正在启动 httpd： [确定] [root@slave ~] # service httpd start 正在启动 httpd： [确定]

(4).修改配置文件

master:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 [root@master ~] # cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 15251076067@163.com } notification_email_from root smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 101 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.18.200 } } virtual_server 192.168.18.200 80 { delay_loop 6 lb_algo rr lb_kind DR nat_mask 255.255.255.0 protocol TCP real_server 192.168.18.201 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } real_server 192.168.18.202 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } sorry_server 127.0.0.1 80 #增加一行sorry_server }

slave:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 [root@slave ~] # cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 15251076067@163.com } notification_email_from root smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.18.200 } } virtual_server 192.168.18.200 80 { delay_loop 6 lb_algo rr lb_kind DR nat_mask 255.255.255.0 protocol TCP real_server 192.168.18.201 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } real_server 192.168.18.202 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } sorry_server 127.0.0.1 80 #增加一行sorry_server }

(5).关闭所有的real server并重新启动一下master与slave的keepalived

1 2 3 4 5 6 7 8 9 10 [root@node1 ~] # service httpd stop 停止 httpd： [确定] [root@node2 ~] # service httpd stop 停止 httpd： [确定] [root@master ~] # service keepalived restart 停止 keepalived： [确定] 正在启动 keepalived： [确定] [root@slave ~] # service keepalived restart 停止 keepalived： [确定] 正在启动 keepalived： [确定]

(6).查看一下lvs

(7).测试

注，sorry_server测试成功，下面我们继续。

10.怎么完成维护模式keepalived切换？

问题：我们一般进行主从切换测试时都是关闭keepalived或关闭网卡接口，有没有一种方法能实现在不关闭keepalived下或网卡接口来实现维护呢？方法肯定是有的，在keepalived新版本中，支持脚本vrrp_srcipt，具体如何使用大家可以man keepalived.conf查看。下面我们来演示一下具体怎么实现。

(1).定义脚本

1 2 3 4 5 6 7 vrrp_srcipt chk_schedown { script "[ -e /etc/keepalived/down ] && exit 1 || exit 0" interval 1 #监控间隔 weight -5 #减小优先级 fall 2 #监控失败次数 rise 1 #监控成功次数 }

(2).执行脚本

1 2 3 track_script { chk_schedown #执行chk_schedown脚本 }

(3).修改配置文件

master:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 [root@master ~] # cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 15251076067@163.com } notification_email_from root smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_script chk_schedown { #定义vrrp执行脚本 script "[ -e /etc/keepalived/down ] && exit 1 || exit 0" #查看是否有down文件，有就进入维护模式 interval 1 #监控间隔时间 weight -5 #降低优先级 fall 2 #失败次数 rise 1 #成功数次 } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 101 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.18.200 } track_script { #执行脚本 chk_schedown } } virtual_server 192.168.18.200 80 { delay_loop 6 lb_algo rr lb_kind DR nat_mask 255.255.255.0 protocol TCP real_server 192.168.18.201 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } real_server 192.168.18.202 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } sorry_server 127.0.0.1 80 }

slave:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 [root@slave ~] # cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 15251076067@163.com } notification_email_from root smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_script chk_schedown { script "[ -e /etc/keepalived/down ] && exit 1 || exit 0" interval 1 weight -5 fall 2 rise 1 } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.18.200 } track_script { chk_schedown } } virtual_server 192.168.18.200 80 { delay_loop 6 lb_algo rr lb_kind DR nat_mask 255.255.255.0 protocol TCP real_server 192.168.18.201 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } real_server 192.168.18.202 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } sorry_server 127.0.0.1 80

(4).测试

master:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 [root@master keepalived] # touch down #新建一下down文件 [root@master keepalived] # ll 总用量 4 -rw-r--r-- 1 root root 0 8月 22 13:39 down -rw-r--r-- 1 root root 1317 8月 22 13:35 keepalived.conf [root@master keepalived] # tail -f /var/log/messages #查看一下日志 Aug 22 13:43:52 master Keepalived_vrrp[12003]: VRRP_Instance(VI_1) Entering MASTER STATE Aug 22 13:43:52 master Keepalived_vrrp[12003]: VRRP_Instance(VI_1) setting protocol VIPs. Aug 22 13:43:52 master Keepalived_vrrp[12003]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.18.200 Aug 22 13:43:52 master Keepalived_vrrp[12003]: VRRP_Instance(VI_1) Received higher prio advert Aug 22 13:43:52 master Keepalived_vrrp[12003]: VRRP_Instance(VI_1) Entering BACKUP STATE Aug 22 13:43:52 master Keepalived_vrrp[12003]: VRRP_Instance(VI_1) removing protocol VIPs. Aug 22 13:43:52 master Keepalived_healthcheckers[12002]: Netlink reflector reports IP 192.168.18.200 added Aug 22 13:43:52 master Keepalived_healthcheckers[12002]: Netlink reflector reports IP 192.168.18.200 removed Aug 22 13:43:52 master Keepalived_healthcheckers[12002]: SMTP alert successfully sent. Aug 22 13:43:52 master Keepalived_healthcheckers[12002]: SMTP alert successfully sent. ^C [root@master keepalived] # ip add show #查看VIP 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 UP qlen 1000 link /ether 00:0c:29:4b:a1:85 brd ff:ff:ff:ff:ff:ff inet 192.168.18.208 /24 brd 192.168.18.255 scope global eth0 inet6 fe80::20c:29ff:fe4b:a185 /64 scope link valid_lft forever preferred_lft forever

slave:

1 2 3 4 5 6 7 8 9 10 11 12 [root@slave ~] # ip addr show #查看一下VIP已转移到slave上 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 UP qlen 1000 link /ether 00:0c:29:f9:e6:26 brd ff:ff:ff:ff:ff:ff inet 192.168.18.207 /24 brd 192.168.18.255 scope global eth0 inet 192.168.18.200 /32 scope global eth0 inet6 fe80::20c:29ff:fef9:e626 /64 scope link valid_lft forever preferred_lft forever

好了，自写监测脚本，完成维护模式切换，到这里就演示成功，下面我们来解决最后一个问题，就是keepalived主从切换的邮件通告。

11.如何在keepalived故障时(或主备切换时)，发送警告邮件给指定的管理员？

(1).keepalived通知脚本进阶示例

下面的脚本可以接受选项，其中

-s, --service SERVICE,...：指定服务脚本名称，当状态切换时可自动启动、重启或关闭此服务；

-a, --address VIP: 指定相关虚拟路由器的VIP地址；

-m, --mode {mm|mb}：指定虚拟路由的模型，mm表示主主，mb表示主备；它们表示相对于同一种服务而方，其VIP的工作类型；

-n, --notify {master|backup|fault}：指定通知的类型，即vrrp角色切换的目标角色；

-h, --help：获取脚本的使用帮助；

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 #!/bin/bash # Author: freeloda # description: An example of notify script # Usage: notify.sh -m|--mode {mm|mb} -s|--service SERVICE1,... -a|--address VIP -n|--notify {master|backup|falut} -h|--help contact= '1521076067@163.com' helpflag=0 serviceflag=0 modeflag=0 addressflag=0 notifyflag=0 Usage() { echo "Usage: notify.sh [-m|--mode {mm|mb}] [-s|--service SERVICE1,...] <-a|--address VIP> <-n|--notify {master|backup|falut}>" echo "Usage: notify.sh -h|--help" } ParseOptions() { local I=1; if [ $ # -gt 0 ]; then while [ $I - le $ # ]; do case $1 in -s|--service) [ $ # -lt 2 ] && return 3 serviceflag=1 services=(` echo $2| awk -F "," '{for(i=1;i<=NF;i++) print $i}' `) shift 2 ;; -h|--help) helpflag=1 return 0 shift ;; -a|--address) [ $ # -lt 2 ] && return 3 addressflag=1 vip=$2 shift 2 ;; -m|--mode) [ $ # -lt 2 ] && return 3 mode=$2 shift 2 ;; -n|--notify) [ $ # -lt 2 ] && return 3 notifyflag=1 notify=$2 shift 2 ;; *) echo "Wrong options..." Usage return 7 ;; esac done return 0 fi } #workspace=$(dirname $0) RestartService() { if [ ${ #@} -gt 0 ]; then for I in $@; do if [ -x /etc/rc .d /init .d/$I ]; then /etc/rc .d /init .d/$I restart else echo "$I is not a valid service..." fi done fi } StopService() { if [ ${ #@} -gt 0 ]; then for I in $@; do if [ -x /etc/rc .d /init .d/$I ]; then /etc/rc .d /init .d/$I stop else echo "$I is not a valid service..." fi done fi } Notify() { mailsubject= "`hostname` to be $1: $vip floating" mailbody= "`date '+%F %H:%M:%S'`, vrrp transition, `hostname` changed to be $1." echo $mailbody | mail -s "$mailsubject" $contact } # Main Function ParseOptions $@ [ $? - ne 0 ] && Usage && exit 5 [ $helpflag - eq 1 ] && Usage && exit 0 if [ $addressflag - ne 1 -o $notifyflag - ne 1 ]; then Usage exit 2 fi mode=${mode:-mb} case $notify in 'master' ) if [ $serviceflag - eq 1 ]; then RestartService ${services[*]} fi Notify master ;; 'backup' ) if [ $serviceflag - eq 1 ]; then if [ "$mode" == 'mb' ]; then StopService ${services[*]} else RestartService ${services[*]} fi fi Notify backup ;; 'fault' ) Notify fault ;; *) Usage exit 4 ;; esac

(2).在keepalived.conf配置文件中，其调用方法如下所示：

notify_master "/etc/keepalived/notify.sh -n master -a 192.168.18.200"

notify_backup "/etc/keepalived/notify.sh -n backup -a 192.168.18.200"

notify_fault "/etc/keepalived/notify.sh -n fault -a 192.168.18.200"

(3).修改配置文件

master:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 [root@master keepalived] # cat keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 15251076067@163.com } notification_email_from root smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_script chk_schedown { script "[ -e /etc/keepalived/down ] && exit 1 || exit 0" interval 1 weight -5 fall 2 rise 1 } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 101 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.18.200 } track_script { chk_schedown } #增加以下三行 notify_master "/etc/keepalived/notify.sh -n master -a 192.168.18.200" notify_backup "/etc/keepalived/notify.sh -n backup -a 192.168.18.200" notify_fault "/etc/keepalived/notify.sh -n fault -a 192.168.18.200" } virtual_server 192.168.18.200 80 { delay_loop 6 lb_algo rr lb_kind DR nat_mask 255.255.255.0 protocol TCP real_server 192.168.18.201 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } real_server 192.168.18.202 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } sorry_server 127.0.0.1 80 }

slave:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 [root@slave keepalived] # cat keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 15251076067@163.com } notification_email_from root smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_script chk_schedown { script "[ -e /etc/keepalived/down ] && exit 1 || exit 0" interval 1 weight -5 fall 2 rise 1 } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.18.200 } track_script { chk_schedown } #增加以下三行 notify_master "/etc/keepalived/notify.sh -n master -a 192.168.18.200" notify_backup "/etc/keepalived/notify.sh -n backup -a 192.168.18.200" notify_fault "/etc/keepalived/notify.sh -n fault -a 192.168.18.200" } virtual_server 192.168.18.200 80 { delay_loop 6 lb_algo rr lb_kind DR nat_mask 255.255.255.0 protocol TCP real_server 192.168.18.201 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } real_server 192.168.18.202 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 2 nb_get_retry 3 delay_before_retry 1 } } sorry_server 127.0.0.1 80 }

(4).增加脚本

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 [root@slave keepalived] # pwd /etc/keepalived [root@slave keepalived] # vim notify.sh [root@slave keepalived] # cat notify.sh #!/bin/bash # Author: freeloda # description: An example of notify script # Usage: notify.sh -m|--mode {mm|mb} -s|--service SERVICE1,... -a|--address VIP -n|--notify {master|backup|falut} -h|--help contact= '15251076067@163.com' helpflag=0 serviceflag=0 modeflag=0 addressflag=0 notifyflag=0 Usage() { echo "Usage: notify.sh [-m|--mode {mm|mb}] [-s|--service SERVICE1,...] <-a|--address VIP> <-n|--notify {master|backup|falut}>" echo "Usage: notify.sh -h|--help" } ParseOptions() { local I=1; if [ $ # -gt 0 ]; then while [ $I - le $ # ]; do case $1 in -s|--service) [ $ # -lt 2 ] && return 3 serviceflag=1 services=(` echo $2| awk -F "," '{for(i=1;i<=NF;i++) print $i}' `) shift 2 ;; -h|--help) helpflag=1 return 0 shift ;; -a|--address) [ $ # -lt 2 ] && return 3 addressflag=1 vip=$2 shift 2 ;; -m|--mode) [ $ # -lt 2 ] && return 3 mode=$2 shift 2 ;; -n|--notify) [ $ # -lt 2 ] && return 3 notifyflag=1 notify=$2 shift 2 ;; *) echo "Wrong options..." Usage return 7 ;; esac done return 0 fi } #workspace=$(dirname $0) RestartService() { if [ ${ #@} -gt 0 ]; then for I in $@; do if [ -x /etc/rc .d /init .d/$I ]; then /etc/rc .d /init .d/$I restart else echo "$I is not a valid service..." fi done fi } StopService() { if [ ${ #@} -gt 0 ]; then for I in $@; do if [ -x /etc/rc .d /init .d/$I ]; then /etc/rc .d /init .d/$I stop else echo "$I is not a valid service..." fi done fi } Notify() { mailsubject= "`hostname` to be $1: $vip floating" mailbody= "`date '+%F %H:%M:%S'`, vrrp transition, `hostname` changed to be $1." echo $mailbody | mail -s "$mailsubject" $contact } # Main Function ParseOptions $@ [ $? - ne 0 ] && Usage && exit 5 [ $helpflag - eq 1 ] && Usage && exit 0 if [ $addressflag - ne 1 -o $notifyflag - ne 1 ]; then Usage exit 2 fi mode=${mode:-mb} case $notify in 'master' ) if [ $serviceflag - eq 1 ]; then RestartService ${services[*]} fi Notify master ;; 'backup' ) if [ $serviceflag - eq 1 ]; then if [ "$mode" == 'mb' ]; then StopService ${services[*]} else RestartService ${services[*]} fi fi Notify backup ;; 'fault' ) Notify fault ;; *) Usage exit 4 ;; esac

(5).给脚本增加执行权限

1 [root@slave keepalived] # chmod +x notify.sh

(6).将master上脚本复制到slave上

1 [root@slave keepalived] # scp -p notify.sh root@192.168.18.207:/etc/keepalived/

(7).测试一下脚本

1 2 3 4 5 6 7 [root@slave keepalived] # ./notify.sh -h Usage: notify.sh [-m|--mode {mm|mb}] [-s|--service SERVICE1,...] <-a|--address VIP> <-n|--notify {master|backup|falut}> Usage: notify.sh -h|--help [root@slave keepalived] # ./notify.sh --help Usage: notify.sh [-m|--mode {mm|mb}] [-s|--service SERVICE1,...] <-a|--address VIP> <-n|--notify {master|backup|falut}> Usage: notify.sh -h|--help [root@slave keepalived] # ./notify.sh -m mb -a 1.1.1.1 -n master

(8).查看一下邮件

注，大家可以看到成功收到邮件，测试成功。在模拟故障时先重启一下keepalived服务。

(9).模拟故障

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 [root@master keepalived] # ip addr show #查看一下VIP 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 UP qlen 1000 link /ether 00:0c:29:4b:a1:85 brd ff:ff:ff:ff:ff:ff inet 192.168.18.208 /24 brd 192.168.18.255 scope global eth0 inet 192.168.18.200 /32 scope global eth0 inet6 fe80::20c:29ff:fe4b:a185 /64 scope link valid_lft forever preferred_lft forever [root@master keepalived] # touch down #进入维护模式 [root@master keepalived] # ll 总用量 8 -rw-r--r-- 1 root root 0 8月 22 14:39 down -rw-r--r-- 1 root root 1543 8月 22 14:04 keepalived.conf -rwxr-xr-x 1 root root 2516 8月 22 14:15 notify.sh [root@master keepalived] # ip addr show #再次查看VIP 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 UP qlen 1000 link /ether 00:0c:29:4b:a1:85 brd ff:ff:ff:ff:ff:ff inet 192.168.18.208 /24 brd 192.168.18.255 scope global eth0 inet6 fe80::20c:29ff:fe4b:a185 /64 scope link valid_lft forever preferred_lft forever [root@slave keepalived] # ip addr show #大家可以看到VIP成功移动到slave上 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 UP qlen 1000 link /ether 00:0c:29:f9:e6:26 brd ff:ff:ff:ff:ff:ff inet 192.168.18.207 /24 brd 192.168.18.255 scope global eth0 inet 192.168.18.200 /32 scope global eth0 inet6 fe80::20c:29ff:fef9:e626 /64 scope link valid_lft forever preferred_lft forever

(10).查看一下邮件

注，大家可以看到，主备切换时，会发送邮件报警，好了到这里所有演示全部完成。希望大家有所收获^_^……

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