在日常应用环境中,我们会遇到这样一种lvs部署环境,所有的dr以及的rs server都在一个局域网环境中,但只有一个公网ip,而又需要将应用发布到internet上,都知道lvs的最好的模式就是所有的server都有一个公网ip,但很多时候公网资源稀缺,当出现只有一个公网ip的时候,怎么实现lvs对外发布呢?
Lvs(lvs/dr模式)单个公网ip高可用应用案例
如图所示为整体的拓扑图:
一.部署前说明:
(1)系统版本: centos 6.6(64位)
(2)角色及ip相关信息:
角色名称 | ip信息 |
客户端(CIP) | 192.168.1.128/24 && Gateway:192.168.1.254 |
主调度器(master-dr) | eth0:172.51.96.119/24 && Gateway:172.51.97.1 |
备调度器(backup-dr) | eth0:172.51.96.105/24 && Gateway:172.51.97.1 |
后端web1(rs rip1) | eth0:172.51.96.235/24 && Gateway:172.51.96.1 |
后端web2(rs rip2) | eth0:172.51.96.236/24 && Gateway:172.51.96.1 |
公网ip信息 | 172.51.97.175/24 && Gateway:172.51.97.1 |
vip地址 | 172.51.97.175/24 |
Route1 | eth0:172.51.97.1/24 & eth1:10.10.10.254 |
Route2 | eth0:172.51.96.1/24 eth1:10.10.1.254 |
Route3 | eth0:192.168.1.254/24 eth1:10.10.100.254 |
注意:实际应用环境中,互联网之间连路都是联通的,这里椭圆区域代表整个internet。
(3)相关中间件信息
keepalive版本信息: keepalived-1.2.15
httpd版本信息: httpd-2.2 (提供http服务)
ipvsadm版本信息: ipvsadm-1.2.1
二.部署操作:
负载均衡器上配置操作
(1)分别在Master_DR和backup_DR上安装Keepalive,ipvsadm所需要的相关依赖包:
# yum install openssl-devel popt-devel libnl-devel kernel-devel -y
(2)分别在Master_DR和backup_DR上安装Keepalive以及ipvsadm,如下:
1. 安装ipvsadm软件
# yum install ipvsadm -y
2. 编译安装keepalive
1.1 keepalived的源码获取
keepalived源码包我们可以到keepalived的官网:http://www.keepalived.org/去下载,相关说明文档亦可在其官网查看,比如keepalived的使用,相关配置说明,这里演示的版本为:1.2.15
# cd ~# wget http://www.keepalived.org/software/keepalived-1.2.15.tar.gz
1.2 编译安装keepalived
<--编译安装keepalived-->
# ln -s /usr/src/kernels/2.6.32-573.18.1.el6.x86_64/ /usr/src/linux# tar zxvf keepalived-1.2.15.tar.gz -C /usr/local/src# cd /usr/local/src/keepalived-1.2.15/# ./configure \ --prefix=/usr/local/keepalived \ --with-kernel-dir=/usr/src/kernels/2.6.32-573.18.1.el6.x86_64# make make install
<--对keepalived进行相关路径优化调整-->
<---拷贝keepalived相关启动命令---># cp /usr/local/keepalived/sbin/keepalived /usr/sbin/ # cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ <---将keepalived启动脚本添加到系统服务---># cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/# chkconfig --add keepalived # chkconfig --level 2345 keepalived on <---创建keepalived相关配置文件---># mkdir -p /etc/keepalived # cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived
备注说明:1.keepalived安装完成后,相关路径如下:安装目录为:/usr/lccal/keepalived, 配置文件路径为:/etc/keepalive/2.安装完成后,需要将启动脚本复制到/etc/ini.d/下3.注意一定要执行述上的相关操作,不然有可能导致keepalived服务起不来
(3)分别配置Lvs_Master_DR以及Lvs_Backup_DR上的keepalive实例,如下所示:
1. master_dr配置代码示例(主调度器)
vim /etc/keepalived/keepalived.conf
内容如下
! Configuration File for keepalived global_defs { notification_email { [email protected] } notification_email_from [email protected] smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id DR_Master } #vrrp_script check_nginx { # script "/etc/keepalived/scripts/check_nginx.sh" # interval 3 # weight -5 #} vrrp_instance http { state BACKUP interface eth0 lvs sync daemon interface eth0 dont_track_primary nopreempt track_interface { eth0 eth1 } mcast_src_ip 172.51.96.105 garp_master_delay 6 virtual_router_id 60 priority 110 advert_int 1 authentication { auth_type PASS autp_pass 1234 } virtual_ipaddress { 172.51.97.175/24 brd 172.51.97.255 dev eth0 label eth0:1 } virtual_routes { 172.51.97/24 dev eth0 } # track_script { # check_nginx # } notify_master /etc/keepalived/scripts/state_master.sh notify_backup /etc/keepalived/scripts/state_backup.sh notify_fault /etc/keepalived/scripts/state_fault.sh } virtual_server 172.51.97.175 80 { delay_loop 1 lb_algo rr lb_kind DR persistence_timeout 30 nat_mask 255.255.255.0 protocol TCP real_server 172.51.96.235 80 { weight 1 notify_down /etc/keepalived/scripts/rs_state.sh HTTP_GET { url { path /info.php status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 172.51.96.236 80 { weight 1 notify_down /etc/keepalived/scripts/rs_state.sh HTTP_GET { url { path /info.php status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } }
2 backup_dr配置示例(备调度器)
vim /etc/keepalived/keepalived.conf
内容如下
! Configuration File for keepalived global_defs { notification_email { [email protected] } notification_email_from [email protected] smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id DR_BACKUP } #vrrp_script check_nginx { # script "/etc/keepalived/scripts/check_nginx.sh" # interval 3 # weight -5 #} vrrp_instance http { state BACKUP interface eth0 lvs sync daemon interface eth0 dont_track_primary track_interface { eth0 eth1 } mcast_src_ip 172.51.96.119 garp_master_delay 6 virtual_router_id 60 priority 105 advert_int 1 authentication { auth_type PASS autp_pass 1234 } virtual_ipaddress { 172.51.97.175/24 brd 172.51.97.255 dev eth0 label eth0:1 } virtual_routes { 172.51.97.175/24 dev eth0 } # track_script { # check_nginx # } notify_master /etc/keepalived/scripts/state_master.sh notify_backup /etc/keepalived/scripts/state_backup.sh notify_fault /etc/keepalived/scripts/state_fault.sh } virtual_server 172.51.97.175 80 { delay_loop 1 lb_algo rr lb_kind DR persistence_timeout 30 nat_mask 255.255.255.0 protocol TCP real_server 172.51.96.235 80 { weight 1 notify_down /etc/keepalived/scripts/rs_state.sh HTTP_GET { url { path /info.php status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 172.51.96.236 80 { weight 1 notify_down /etc/keepalived/scripts/rs_state.sh HTTP_GET { url { path /info.php status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } }
注意:关于vip,如果vip不在DIP所在的网段内,那么vip一定要配置在dr与后端上游RS Server直连的网卡上,不然就会出现无法访问的情况;
3.分别在主调度server和备调度server编写以下脚本,如
i 当调度器为切换master server时,记录切换时间日志
vim /etc/keepalived/scripts/state_master.sh
代码如下:
#!/bin/bash echo -e >> $LOGFILE host=CN-SH-DR01 #设置当前的主机名 LOGFILE="/var/log/keepalived-state.log" echo "[Master]" >> $LOGFILE date >> $LOGFILE echo "The ${host} Starting to become master server...." >> $LOGFILE 2>&1 echo "Please run the “ipvsadm -Ln” check the keepalived state ..." >> $LOGFILE echo ".........................................................................!">> $LOGFILE echo >>$LOGFILE
ii 当调度器为切换backup server时,记录切换时间日志
vim /etc/keepalived/scripts/state_backup.sh
代码如下:
#!/bin/bash echo -e >> $LOGFILE host=CN-SH-DR01 #设置当前的主机名 LOGFILE="/var/log/keepalived-state.log" echo "[Backup]" >> $LOGFILE date >> $LOGFILE echo "The ${host} Starting to become Backup server...." >> $LOGFILE 2>&1 echo "Please run the “ipvsadm -Ln” check the state ..." >> $LOGFILE echo "........................................................................!">> $LOGFILE echo >> $LOGFILE
iii 当调度器出现错误时,记录错误时间日志
vim /etc/keepalived/scripts/state_fault.sh
代码如下:
#!/bin/bash echo -e >> $LOGFILE host=CN-SH-DR01 #设置当前的主机名 LOGFILE="/var/log/keepalived-state.log" echo "[fault errot ]" >> $LOGFILE date >> $LOGFILE echo "The ${host} is fault error...." >> $LOGFILE 2>&1 echo "Please check the server state ..." >> $LOGFILE echo "........................................................................!">> $LOGFILE echo >> $LOGFILE
4. 重新启动keepalived服务
# service keepalived restart
后端RS server上配置操作
(1)分别在每个RIP(RIP1,RIP2)上新建一个shell脚本文件,如下操作所示:
# vim /etc/init.d/lvs-dr
脚本内容如下
#!/bin/sh # # Startup script handle the initialisation of LVS # chkconfig: - 28 72 # description: Initialise the Linux Virtual Server for DR # ### BEGIN INIT INFO # Provides: ipvsadm # Required-Start: $local_fs $network $named # Required-Stop: $local_fs $remote_fs $network # Short-Description: Initialise the Linux Virtual Server # Description: The Linux Virtual Server is a highly scalable and highly # available server built on a cluster of real servers, with the load # balancer running on Linux. # description: start LVS of DR-RIP LOCK=/var/lock/ipvsadm.lock VIP=172.51.97.175 . /etc/rc.d/init.d/functions start() { PID=`ifconfig | grep lo:0 | wc -l` if [ $PID -ne 0 ]; then echo "The LVS-DR-RIP Server is already running !" else /sbin/ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP up /sbin/route add -host $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/eth0/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/eth0/arp_announce echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce /bin/touch $LOCK echo "starting LVS-DR-RIP server is ok !" fi } stop() { /sbin/route del -host $VIP dev lo:0 /sbin/ifconfig lo:0 down >/dev/null 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/eth0/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/eth0/arp_announce echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce rm -rf $LOCK echo "stopping LVS-DR-RIP server is ok !" } status() { if [ -e $LOCK ]; then echo "The LVS-DR-RIP Server is already running !" else echo "The LVS-DR-RIP Server is not running !" fi } case "$1" in start) start ;; stop) stop ;; restart) stop start ;; status) status ;; *) echo "Usage: $1 {start|stop|restart|status}" exit 1 esac exit 0
注意:关于arp仰制,最好也把RIP上同DIR直连的网卡物理网卡也设置arp仰制,如上eth1所示。
授权并启动该脚本
# chmod 777 /etc/init.d/lvs-dr
# service lvd-dr start
(2)分别在每个RIP上安装http服务,并创建测试页,如下分别为RIP上测试页面:
RIP1(172.51.96.235)上的测试页:
RIP2(172.51.96.236)上的测试页:
三.测试验证:
我们可以通过messages查看vip抢夺情况,如下所示:
从上面我们可以看到cn-sh-sq-web01由于优先级为110>cn-sh-sq-web02的优先级(105),
顺利竞选成为master,这里我们可以在cn-sh-sq-web01上可以观察到vip的存在,如下图所示:
同时日志记录脚本也会记录相关信息:
[[email protected] ~]# tail -f /var/log/keepalived-state.log [Backup] Wed Mar 9 21:56:25 CST 2016 The CN-SH-DR01 Starting to become Backup server.... Please run the “ipvsadm -Ln” check the state ... ...............................................................................! [Master] Wed Mar 9 21:56:28 CST 2016 The CN-SH-DR01 Starting to become master server.... Please run the “ipvsadm -Ln” check the keepalived state ... ...............................................................................!
这时在CIP访问http://172.51.97.175 即可访问页面
这里我们用VMware来模拟客户端,其中客户端的ip信息如下:
访问http://172.51.97.175 可以看到后端两台rs sever页面轮询出现如下所示:
我们在maste-dr运行“ipvsadm -Ln -c”可以看到连接情况,:
至此,整个单个公网ip部署lvs高可用基本上部署完成了
总结:lvs DR模式中可以存在vip不与DIP同一网段,比如当整个应用环境中只有一个公网ip的情况下,我们可以把公网ip充当vip,绑定到dr与上游各RS server直连的那个网卡上,这样就可以顺利实现lvs对外提供服务,需要注意的是lvs对整个网络的环境要求特别高。