keepalived + lvs高可用web服务

    xiaoxiao2021-04-18  66

    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

    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).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

    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      -> 127.0.0.1:80                 Local   1      0          0

    (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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