Centos6.3实现LVS+Keepalive实现http服务的双机热备

时间:2015-03-13 11:16来源:blog.51cto.com 作者:“技术成就未来” 博 举报 点击:

一、初始环境部署

    两台centos 6.3 均最小欢安装,初始化系统环境

    主机配置   master: 192.168.0.250 24

               backup: 192.168.0.249 24

               vip   : 192.168.0.66  24

               测试端: 192.168.0.252 24

    在两台主上均以下操作,配置本地yum源 

    cd /etc/yum.repos.d/

    mv CentOS-Base.repo CentOS-Debuginfo.repo CentOS-Vault.repo /root/

    vi CentOS-Media.repo

    [c6-media]

    name=CentOS-$releasever - Media

    baseurl=file:///mnt/

            file:///media/cdrom/

            file:///media/cdrecorder/

    gpgcheck=0

    enabled=1

    mount /dev/cdrom /mnt/

    安装基本编译工具,以及其他工具包

    

    yum -y install make gcc openssl-devel

    yum -y install lrzsz ipvsadm sendmail httpd

二、安装lVS 和 keepalived 软件包

    查看内核是否支持lvs

    modprobe -l |grep ipvs    

    kernel/net/netfilter/ipvs/ip_vs.ko

    kernel/net/netfilter/ipvs/ip_vs_rr.ko

    kernel/net/netfilter/ipvs/ip_vs_wrr.ko

    kernel/net/netfilter/ipvs/ip_vs_lc.ko

    kernel/net/netfilter/ipvs/ip_vs_wlc.ko

    kernel/net/netfilter/ipvs/ip_vs_lblc.ko

    kernel/net/netfilter/ipvs/ip_vs_lblcr.ko

    kernel/net/netfilter/ipvs/ip_vs_dh.ko 

    kernel/net/netfilter/ipvs/ip_vs_sh.ko

    kernel/net/netfilter/ipvs/ip_vs_sed.ko

    kernel/net/netfilter/ipvs/ip_vs_nq.ko

    kernel/net/netfilter/ipvs/ip_vs_ftp.ko

    出现以上信息表示支持,kernel2.6 以后支持

    在www.keepalived.org 下载keepalived-1.2.15.tar.gz

    tar -zxvf keepalived-1.2.15.tar.gz

    cd keepalived-1.2.15

    ./configure --sysconf=/etc --with-kernel-dir=/usr/src/kernels/2.6.32-279.el6.x86_64

    make && make install

    ln -s /usr/local/sbin/keepalived /sbin/   (将keepalived指向/sbin/)

    vi /etc/keepalived/keepalived.conf

    

    ! Configuration File for keepalived

 

    global_defs {

    notification_email {

     18792525964@139.com     (这里是发送报警邮件地址)

     acassen@firewall.loc

     failover@firewall.loc

     sysadmin@firewall.loc

     }

     notification_email_from Alexandre.Cassen@firewall.loc

     smtp_server 192.168.0.250(这是右键服务器地址)

     smtp_connect_timeout 30  (连接smtp服务超时时间)

     router_id LVS_DEVEL

     }

 

     vrrp_instance VI_1 {

     state MASTER              (制定服务器角色)

     interface eth0

     virtual_router_id 51      (虚拟路由id,一个集群id必须一样)

     priority 100              (角色优先级,数值越大优先级越高)

     advert_int 1              (master与backup同步检查的时间间隔,单位秒)

     authentication {    

        auth_type PASS         (验证类型,有PASS和AH)

        auth_pass 1111         (验证密钥,两台机器必须一致)

     }

     virtual_ipaddress {

        192.168.0.66            (虚拟IP地址)

     }

     }

 

     virtual_server 192.168.0.66 80 {    

     delay_loop 6               (运行情况检查时间间隔)

     lb_algo rr                 (设置负载调度算法)

     lb_kind DR                 (负载均衡机制,设置DR,还有NAT和TUN模式)

     nat_mask 255.255.255.0

     persistence_timeout 50

     protocol TCP               (设置传输协议为TCP)

 

     real_server 192.168.0.250 80 {

        weight 1                (服务器权值设置)

        TCP_CHECK {

            connect_timeout 3   (表示3秒无响应超市)

            nb_get_retry 3      (重试次数3次)

            delay_before_retry 3(重试时间间隔3秒)

        }

     }

 

 

     real_server 192.168.0.249 80 {

        weight 1           

            TCP_CHECK {

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

      }

 

    }

    在master主机上配置如上,在backup主机祝需要修改

    state BACKUP

    priority 90

    vi /etc/init.d/lvsrs  (编写realserver启动脚本)

    

    #!/bin/bash

    NS_VIP=192.168.0.66

 

    /etc/rc.d/init.d/functions

 

    case "$1" in

    start)

         /sbin/ifconfig lo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP up

         /sbin/route add -host $SNS_VIP dev lo:0

         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

         syscty -p > /dev/null 2>&1

         echo "RealServer Start Ok"

         ;;

     stop)

         ifconfig lo:0 down

         route del $SNS_VIP >/dev/null 2>&1

         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

         echo "RealServer Stoped"

         ;;

     *)

         echo "Usage: $0 {start|stop}"

     exit 1

     esac

     exit 0

 

     chmod 755 /etc/init.d/lvsrs

     /etc/init.d/keepalived start

     /etc/init.d/lvsrs start

三、测试配置正确

    在master上执行

    echo "This is master" > /var/www/html/index.html

    service httpd start

    在backup上执行

    echo "This is backup" > /var/www/html/index.html

    service httpd start

    两台机器均关闭防火墙 

    service iptables stop

    在测试端浏览器输入http://192.168.0.66

    wKioL1UBIHPBkhzrAACPFtraDso656.jpg

    接着停掉master上的httpd服务

    service httpd stop

    wKiom1UBJteh0-rYAACLSPc4QM0570.jpg

    我们可看到已经切换到backup服务器,检查backup的日志

    tail -f /var/log/messages

   

    Mar 12 03:35:22 backup Keepalived_healthcheckers[3123]: Removing service [192.168.0.249]:80 from VS [192.168.0.66]:80

    Mar 12 03:35:22 backup Keepalived_healthcheckers[3123]: SMTP connection ERROR to [192.168.0.250]:25.

    Mar 12 03:39:46 backup Keepalived_healthcheckers[3123]: TCP connection to [192.168.0.249]:80 success.

    Mar 12 03:39:46 backup Keepalived_healthcheckers[3123]: Adding service [192.168.0.249]:80 to VS [192.168.0.66]:80

    Mar 12 03:39:46 backup Keepalived_healthcheckers[3123]: Remote SMTP server [192.168.0.250]:25 connected.

    Mar 12 03:39:46 backup Keepalived_healthcheckers[3123]: Error reading data from remote SMTP server [192.168.0.250]:25.

    Mar 12 03:39:55 backup Keepalived_healthcheckers[3123]: TCP connection to [192.168.0.250]:80 failed !!!

    Mar 12 03:39:55 backup Keepalived_healthcheckers[3123]: Removing service [192.168.0.250]:80 from VS [192.168.0.66]:80

    Mar 12 03:39:55 backup Keepalived_healthcheckers[3123]: Remote SMTP server [192.168.0.250]:25 connected.

    Mar 12 03:39:55 backup Keepalived_healthcheckers[3123]: Error reading data from remote SMTP server [192.168.0.250]:25.

    注意:这里master宕机backup接管,master恢复backup依然提供服务,当backup宕机master才会接管服务!不是master恢复 服务又从backup切回master!

    双机热备功能已实现,你会了吗?

 

    

本文出自 “技术成就未来” 博客,请务必保留此出处http://linuxmysqldba.blog.51cto.com/2530817/1619681

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