Keepalived会主动检测web服务器,把有故障的服务器从系统中剔除,在服务器修复以后会重新加入到服务器群众,不影响服务器的正常工作
VRRP:虚拟路由冗余协议 它把一个虚拟路由器的责任动态的分配到局域网中的VRRP中的一台。控制虚拟路由IP地址的VRRP路由器称为主路由器,负责转发数据到虚拟IP地址,一旦主路由出现故障,就把数据包转发到备用的路由器上,虚拟IP地址在路由之间是共享的,其中一个指定为主路由,其余的作为备份路由,如果主路由出现故障,这个虚拟IP地址就会映射到一个备用路由上,这个备份路由就成为主路由 VRRP:能够动态的将一个虚拟路由器的责任指定至同一个VRRP组中的其它路由器上,消除静态路由配置的单点故障,同时切换路由的过程会比较块,主要是在主路由出现故障时,启用备用路由 配置keepalived为实现haproxy高可用的双主模型配置文件示例:
安装keepalived,先配置好两个高可用节点 在两个节点上安装keeoalived 在keepalived中指定vrrp 用不上的话禁用smnp 下载keepalived-1.2.7-5.el5.i386 yum -y install --nogpgcheck localinstall keepalived-1.2.7-5.el5.i386 Scp keepalived-1.2.7-5.el5.i386.rpm node2:/root/复制到另外一个节点 在另外一个节点上再执行yum -y install --nogpgcheck localinstall keepalived-1.2.7-5.el5.i386 安装keepalived cd keepalived keepalived的配置文件keepalived.conf ! Configuration File for keepalived global_defs { notification_email { linuxedu@foxmail.com mageedu@126.com } notification_email_from kanotify@magedu.com smtp_connect_timeout 3 smtp_server 127.0.0.1 router_id LVS_DEVEL } vrrp_script chk_haproxy { script "killall -0 haproxy" interval 1 weight 2 } vrrp_script chk_mantaince_down { script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0" interval 1 weight 2 } vrrp_instance VI_1 { interface eth0 state MASTER # BACKUP for slave routers priority 101 # 100 for BACKUP virtual_router_id 51 garp_master_delay 1 authentication { auth_type PASS auth_pass password } track_interface { eth0 } virtual_ipaddress { 172.16.116.7/16 dev eth0 label eth0:0 } track_script { chk_haproxy chk_mantaince_down } notify_master "/etc/keepalived/notify.sh master" notify_backup "/etc/keepalived/notify.sh backup" notify_fault "/etc/keepalived/notify.sh fault" } vrrp_instance VI_2 { interface eth0 state BACKUP # BACKUP for slave routers priority 100 # 100 for BACKUP virtual_router_id 52 garp_master_delay 1 authentication { auth_type PASS auth_pass password } track_interface { eth0 } virtual_ipaddress { 172.16.116.7/16 dev eth0 label eth0:1 } track_script { chk_haproxy chk_mantaince_down } notify_master "/etc/keepalived/notify.sh master" notify_backup "/etc/keepalived/notify.sh backup" notify_fault "/etc/keepalived/notify.sh fault" } notify.sh脚本的简单示例: #!/bin/bash # Author: MageEdu <linuxedu@foxmail.com> # description: An example of notify script # vip=172.16.116.8 contact='root@localhost' 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 } case "$1" in master) notify master /etc/rc.d/init.d/haproxy start exit 0 ;; backup) notify backup /etc/rc.d/init.d/haproxy restart exit 0 ;; fault) notify fault exit 0 ;; *) echo 'Usage: `basename $0` {master|backup|fault}' exit 1 ;; esac 配置好keepalived以后安装haproxy-1.4.22.tar.gz tar xf haproxy-1.4.20.tar.gz cd haproxy-1.4.20 make TARGET=linux26PREFIX=/usr/local/haproxy install cd /usr/local/haproxy/ mkdir conf logs cd conf/ vim haproxy.cfg /usr/local/haproxy/sbin/haproxy-f /usr/local/haproxy/conf/haproxy.cfg 修改完成后,启动keepalived服务 查看node1与node2上的VIP地址配置node1主机是否为172.16.116.7 eth0:0是否为172.16.116.8 用172.16.116.7测试网页,node1的返回结果是node1.magedu.com 用172.16.116.8测试网页,node2的返回结果是node2.magedu.com
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