一、keepalived简介 1.Keepalived的作用是检测RealServer的健康状态,如果有一台RealServer服务器宕机,Keepalived将检测到,并将宕掉的RealServer服务器从系统中剔除,当RealServer服务器重新恢复正常工作后Keepalived自动将RealServer服务器加入到服务器群中。 2.keeepalived常见模型 <1>主从模型:(主节点修复后服务返回主节点) 定义一个VIP(定义在网卡别名之上) 在vrrp_instance做如下修改: stateMASTER#从节点为BACKUP priority101#指定优先级,数字越大优先级越高,主节点的优先级高于从节点
<2>双主模型: 创建两个虚拟路由器,两个节点互为主从 指定两个vrrp_instance互为主从 virtual_router_id不相同 <3>LVS+keepalived 首先配置LVS 配置keepalived,添加虚拟服务,指定lvs模型及调度算法
实战篇 系统环境:centos6.4-i386 yum-yinstallkeepalived keepalivedi686-1.2.7-3 二、主从模型HA集群
修改主配置文件:vim/etc/keepalived/keepalived.conf
[backcolor=white !important][backcolor=white !important]! Configuration File for keepalived
[backcolor=white !important]global_defs {
[backcolor=white !important]notification_email {
[backcolor=white !important]linuxedu@gmail.com
[backcolor=white !important]mageedu@126.com
[backcolor=white !important]}
[backcolor=white !important]notification_email_from kanotify@magedu.com
[backcolor=white !important]smtp_connect_timeout 3
[backcolor=white !important]smtp_server 127.0.0.1 #邮件发送者为本地主机
[backcolor=white !important]router_id LVS_DEVEL
[backcolor=white !important]}
[backcolor=white !important]vrrp_script chk_haproxy {
[backcolor=white !important]script "killall -0 haproxy"
[backcolor=white !important]interval 1
[backcolor=white !important]weight 2
[backcolor=white !important]}
[backcolor=white !important]vrrp_script chk_mantaince_down {
[backcolor=white !important]script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
[backcolor=white !important]interval 1
[backcolor=white !important]weight -2
[backcolor=white !important]}
[backcolor=white !important]vrrp_instance VI_1 { #vrrp实例
[backcolor=white !important]interface eth0
[backcolor=white !important]state MASTER # 从节点为BACKUP
[backcolor=white !important]priority 101 # 指定优先级,数字越大优先级越高
[backcolor=white !important]virtual_router_id 51
[backcolor=white !important]garp_master_delay 1
[backcolor=white !important]authentication {
[backcolor=white !important]auth_type PASS
[backcolor=white !important]auth_pass password
[backcolor=white !important]}
[backcolor=white !important]track_interface {
[backcolor=white !important]eth1
[backcolor=white !important]}
[backcolor=white !important]virtual_ipaddress {
[backcolor=white !important]172.16.15.114/16 dev eth1 label eth1:0 #指定VIP及网卡别名
[backcolor=white !important]}
[backcolor=white !important]track_script {
[backcolor=white !important]chk_haproxy
[backcolor=white !important]chk_mantaince_down
[backcolor=white !important]}
[backcolor=white !important]notify_master "/etc/keepalived/notify.sh master"
[backcolor=white !important]notify_backup "/etc/keepalived/notify.sh backup"
[backcolor=white !important]notify_fault "/etc/keepalived/notify.sh fault"
[backcolor=white !important]}
[backcolor=white !important]notify脚本:
[backcolor=white !important]contact='root@localhost'#!/bin/bash
[backcolor=white !important]vip=172.16.15.114 #指定vip
[backcolor=white !important]notify() {
[backcolor=white !important]mailsubject="`hostname` to be $1: $vip floating"
[backcolor=white !important]mailbody="`date '+%F %H:%M:%S'`: vrrp transition, `hostname` changed to be $1"
[backcolor=white !important]echo $mailbody | mail -s "$mailsubject" $contact
[backcolor=white !important]}
[backcolor=white !important]case "$1" in
[backcolor=white !important]master)
[backcolor=white !important]notify master
[backcolor=white !important]/etc/rc.d/init.d/haproxy start
[backcolor=white !important]exit 0
[backcolor=white !important];;
[backcolor=white !important]backup)
[backcolor=white !important]notify backup
[backcolor=white !important]/etc/rc.d/init.d/haproxy stop
[backcolor=white !important]exit 0
[backcolor=white !important];;
[backcolor=white !important]fault)
[backcolor=white !important]notify fault
[backcolor=white !important]exit 0
[backcolor=white !important];;
[backcolor=white !important]*)
[backcolor=white !important]echo 'Usage: `basename $0` {master|backup|fault}'
[backcolor=white !important]exit 1
[backcolor=white !important];;
[backcolor=white !important]esac
以windows作为客户端访问172.16.15.114 关掉主服务:servicekeepalivedstop
三、双主模型 原理:创建两个虚拟路由器,两个节点互为主从。
! Configuration File for keepalivedglobal_defs {notification_email { linuxedu@gmail.commageedu@126.com}notification_email_from kanotify@magedu.comsmtp_connect_timeout 3smtp_server 127.0.0.1router_id LVS_DEVEL}vrrp_script chk_haproxy {script "killall -0 haproxy"interval 1weight 2}vrrp_script chk_mantaince_down {script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"interval 1weight 2}vrrp_instance VI_1 { #实例1interface eth1state MASTER # BACKUP for slave routerspriority 101 # 100 for BACKUPvirtual_router_id 51garp_master_delay 1authentication {auth_type PASSauth_pass password}track_interface {eth1}virtual_ipaddress { #VIP1172.16.15.115/16 dev eth1 label eth1:1}track_script {chk_haproxychk_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 { #实例2interface eth1state BACKUP # BACKUP for slave routerspriority 100 # 100 for BACKUPvirtual_router_id 52garp_master_delay 1authentication {auth_type PASSauth_pass password}track_interface {eth1}virtual_ipaddress { #VIP2172.16.15.116/16 dev eth1 label eth1:2}track_script {chk_haproxychk_mantaince_down}} 在客户端访问172.16.15.115172.16.15.116 查看IP
四、实现LVS+keepalived(LVS--DR) 1、首先配置LVS负载均衡集群 注:LVS在会后续博文中做详细介绍!!!
添加ipvsadm规则
#yum -y install ipvsadm #安装ipvsadm#ipvsadm #查看ipvsadm信息及规则#ipvsadm -A -t 172.16.15.117:80 -s rr #指定Director(调度器)注释:A(添加规则)-t(指定协议为TCP)172.16.15.117:80(指定VIP及端口)-srr(指定调度算法为rr)#添加real_server
#ipvsadm -a -t 172.16.15.117:80 -r 172.16.15.5 -g#ipvsadm -a -t 172.16.15.117:80 -r 172.16.15.14 -g#ifconfig lo:0 $WEB_VIP netmask 255.255.255.255 broadcast $WEB_VIP #配置VIP,只允许本地回环# /sbin/route add -host $WEB_VIP dev lo:0 #添加本地路由#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注释:在此只添加两个节点-a:添加服务-r172.16.15.5:指定服务IP-g:指定lvs模型(默认DR)2、配置基于keepalived(主从)高可用集群
! Configuration File for keepalivedglobal_defs {notification_email { linuxedu@gmail.commageedu@126.com}notification_email_from kanotify@magedu.comsmtp_connect_timeout 3smtp_server 127.0.0.1router_id LVS_DEVEL}vrrp_script chk_schedown {script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"interval 2weight -2}vrrp_instance VI_1 {interface eth1state MASTERpriority 101virtual_router_id 51garp_master_delay 1authentication {auth_type PASSauth_pass password}track_interface {eth1}virtual_ipaddress {172.16.15.117/16 #指定VIP,此处的VIP和lvs的VIP相同,因此不指定网卡}track_script {chk_schedown}}virtual_server 172.16.15.117 80 { #指定虚拟服务delay_loop 6lb_algo rrlb_kind DRpersistence_timeout 50protocol TCPsorry_server 172.16.15.14 80 #错误页面real_server 172.16.15.5 80 { #指定rserver1weight 1HTTP_GET {url {path /status_code 200 #状态码}connect_timeout 3nb_get_retry 3delay_before_retry 3}}real_server 172.16.15.14 80 { #指定rserver2weight 1HTTP_GET {url {path /status_code 200}connect_timeout 3 #连接超时时间nb_get_retry 3 #尝试连接次数delay_before_retry 3 #每次尝试之前等待的时间}}} 在客户端访问172.16.15.117
|