Centos6.3下haproxy+keepalived+apache配置笔记
keepalived个人简单理解就是实现一个虚IP在keepalived主从服务器之间切换的功能，当主的keeplived挂掉，从机会无缝接管该虚IP。 keepalived它作为一个辅助实现高可用性工具，一般都会配合某个具体服务工作，例如mysql,drbd，haproxy等，本篇介绍的就是haproxy,在前期做好keepalived配置后，做一个切换脚本，当haproxy挂掉后，脚本会立即执行keepalived关闭操作，从而让从机接管,该虚IP其实会和本机的物理IP做绑定，访问虚IP其实就可以理解为访问本机物理IP，该虚IP会在脚本被触发后切换到从机，而后访问虚IP也就是在访问从机物理IP，从而实现haproxy的高可用性。 这个实验模拟的功能其实就是利用haproxy实现apache服务器间的负载均衡，缓解并发压力，并保证haproxy-master若挂掉,haproxy-backup能无缝接管，实现WEB站点负载均衡+高可用性。保证客户端无缝获取网站资源。解决方案：
系统环境：centos6.3apache: httpd-2.4.4haproxy: haproxy-1.4.8keepalived：keepalived-1.2.7
haproxy VIP: 192.168.7.70haproxy-master(haproxy1): 192.168.7.71 ha1.example.comhaproxy-backup(haproxy2): 192.168.7.72 ha2.example.comapache1: 192.168.7.73 www1.example.comapache2: 192.168.7.74 www2.example.com
(haproxy1)为仅haproxy1配置(haproxy2)为仅haproxy2配置(haproxy1，haproxy2)为haproxy1和haproxy2都得配置
部署环境：
1.关闭iptables和SELINUX# service iptables stop# setenforce 0# vi /etc/sysconfig/selinux---------------SELINUX=disabled---------------
2.apache安装配置详见传送门：http://showerlee.blog./2047005/1174141注：haproxy+keepalived其实搭配nginx效果也不错，本人线上因为长期使用apache，所以这篇博文就以apache介绍为主。安装完毕只需配置客户端浏览器访问根页面显示本机IP地址。
一.haproxy安装配置：(haproxy1，haproxy2)# wget http://haproxy.1wt.eu/download/1.4/src/haproxy-1.4.8.tar.gz# tar zxvf haproxy-1.4.8.tar.gz# cd haproxy-1.4.8# uname -a //查看linux内核版本# make TARGET=linux26 PREFIX=/usr/local/haproxy# make install PREFIX=/usr/local/haproxy# useradd -s /sbin/nologin haproxy# passwd haproxy# chown -R haproxy.haproxy /usr/local/haproxy
配置：# vi /usr/local/haproxy/haproxy.cfg-----------------globallog 127.0.0.1local0maxconn 5120chroot /usr/local/haproxyuser haproxygroup haproxydaemonquietnbproc1pidfile /usr/local/haproxy/haproxy.pid#启动服务后后会滚动日志，生产环境建议注释掉debugdefaultslog 127.0.0.1local3modehttpoptionhttplogoptionhttpcloseoptiondontlognull#optionforwardforoptionredispatchretries2maxconn 2000balance sourcecontimeout 5000clitimeout 50000srvtimeout 50000
listen web_proxy :80 server www1192.168.7.73:80weight 5 check inter 2000 rise 2 fall 5 server www2192.168.7.74:80weight 5 check inter 2000 rise 2 fall 5
listen stats :8888mode http#transparentstats uri / haproxy-statsstats realm Haproxy \ statistic#认证stats auth haproxy:password-----------------
启动haproxy# /usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/haproxy.cfg &注：这里加上“&”是为了让haproxy服务后台运行，去掉“&”可实时查看其滚动日志日志：------------------------Available polling systems : sepoll : pref=400,test result OK epoll : pref=300,test result OK poll : pref=200,test result OK select : pref=150,test result OKTotal: 4 (4 usable), will use sepoll.Using sepoll() as the polling mechanism.00000000:web_proxy.accept(0004)=0007 from 00000000:web_proxy.clireq: GET / HTTP/1.100000000:web_proxy.clihdr: Accept: text/html, application/xhtml+xml, */*00000000:web_proxy.clihdr: Accept-Language: zh-CN00000000:web_proxy.clihdr: User-Agent: Mozilla/5.0 (compatible; MSIE
9.0; Windows NT 6.1; WOW64; Trident/5.0)00000000:web_proxy.clihdr: Accept-Encoding: gzip, deflate00000000:web_proxy.clihdr: Host: 192.168.7.7100000000:web_proxy.clihdr: If-Modified-Since: Tue, 28 May 2013 18:22:10
GMT00000000:web_proxy.clihdr: If-None-Match: "10-4ddcb57ecf1ee"00000000:web_proxy.clihdr: Connection: Keep-Alive00000000:web_proxy.srvrep: HTTP/1.1 304 Not Modified00000000:web_proxy.srvhdr: Date: Tue, 28 May 2013 19:48:35 GMT00000000:web_proxy.srvhdr: Server: Apache/2.4.4 (Unix)00000000:web_proxy.srvhdr: Connection: close00000000:web_proxy.srvhdr: ETag: "10-4ddcb57ecf1ee"00000000:web_proxy.srvcls00000000:web_proxy.clicls00000000:web_proxy.closed------------------------
查看是否启动# ps -ef|grep haproxy--------------------------haproxy 2255 10 03:33 ? 00:00:00 /usr/local/haproxy/sbin/haproxy -f/usr/local/haproxy/haproxy.cfgroot 232322910 03:56 pts/1 00:00:00 grep haproxy--------------------------
重启haproxy# pkill haproxy# /usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/haproxy.cfg
其中：haproxy代理：192.168.7.71:80apache1： 192.168.7.73:80apache2： 192.168.7.74:80统计页面监听的端口：8888访问页面：http://192.168.7.71:8888/haproxy-stats认证账号/密码：haproxy/password
总结： 通过日志可以看出，客户端192.168.7.129连接haproxy192.168.7.71的80端口，且客户端无论如何刷新页面，haproxy都只会把访问请求跳转到apache2的192.168.7.74地址，这是因为balance source这个参数会保持会话ID,如果改成balance roundrobin模式，那么客户端会轮流连接两台web服务器，线上还是建议使用balance source,这样会保持某一客户端在长时间内保持他的会话，不会来回跳转。 这里其实已经利用haproxy完成了对两台apache服务器的负载均衡功能，但如何保证负载均衡的高可用性，这里就得利用keepalived的热备功能，保证haproxy1如果挂掉，haproxy2能实时接管，实现网站前端负载均衡高可用，这也是我们目前比较流行的组合haproxy+keepalived。
二.keepalived安装配置：(haproxy1，haproxy2）
# wget http://www.keepalived.org/software/keepalived-1.2.7.tar.gz# tar zxvf keepalived-1.2.7.tar.gz# cd keepalived-1.2.7# ./configure --prefix=/usr/local/keepalived --with-kernel-dir=/usr/src/kernels/2.6.32-279.el6.x86_64# make && make install
设置keepalived启动脚本# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/# mkdir /etc/keepalived# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/# chkconfig keepalived on
(haproxy1）
# vi /etc/keepalived/keepalived.conf----------------------! Configuration File for keepalived
global_defs {router_id LVS_DEVEL}vrrp_instance VI_1 {state MASTERinterface eth0virtual_router_id 51priority 150advert_int 1authentication {auth_type PASSauth_pass 1111}
virtual_ipaddress {192.168.7.70}}----------------------
(haproxy2）
# vi /etc/keepalived/keepalived.conf----------------------! Configuration File for keepalived
global_defs {router_id LVS_DEVEL}vrrp_instance VI_1 {state BACKUPinterface eth0virtual_router_id 51priority 120advert_int 1authentication {auth_type PASSauth_pass 1111}
virtual_ipaddress {192.168.7.70}}----------------------
启动keepalived# service keepalived start# ps -ef |grep keepalived----------------------root 172617220 10:57 ? 00:00:00 sh /etc/keepalived/check_haproxy.shroot 2678 10 11:15 ? 00:00:00 keepalived -Droot 268026780 11:15 ? 00:00:00 keepalived -Droot 268126780 11:15 ? 00:00:00 keepalived -Droot 269121780 11:15 pts/1 00:00:00 grep keepalived-----------------------
创建haproxy+keepalived脚本：实现当haproxy挂掉后，能再次启动haproxy,若无法再次启动则彻底关闭keepalived将VIP交给从机处理。(haproxy1，haproxy2）# vi /etc/keepalived/check_haproxy.sh---------------------#!/bin/bashwhile :dohapid=`ps -C haproxy --no-header |wc -l`if [ $hapid -eq 0 ];then/usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/haproxy.cfgsleep 5 if [ $hapid -eq 0 ];then /etc/init.d/keepalived stop fifisleep 5done--------------------改执行权限# chmod 755 /etc/keepalived/check_haproxy.sh强制后台执行（关闭客户端连接也会继续运行）# nohup sh /etc/keepalived/check_haproxy.sh
注；该脚本参考酒哥的"构建高可用LINUX服务器"一书，需在keepalived开机正常启动后，方可在主从机执行。本人实测，不能将该脚本做开机启动，会导致开机将keepalived服务关闭，如想实现开机自动执行该脚本，估计要做脚本语句优化，这里有兴趣的朋友可以帮忙修改一下。
三.测试：1.在两台机器上分别执行ip add，目前显示VIP在haproxy1上与本机网卡绑定(haproxy1）# ip add-----------------------eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen1000 link/ether 00:0c:29:d2:c6:75 brd ff:ff:ff:ff:ff:ff inet 192.168.7.71/24 brd 192.168.7.255 scope global eth0 inet 192.168.7.70/32 scope global eth0 inet6 fe80::20c:29ff:fed2:c675/64 scope link valid_lft forever preferred_lft forever-----------------------(haproxy2）# ip add-----------------------eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen1000 link/ether 00:0c:29:ff:21:19 brd ff:ff:ff:ff:ff:ff inet 192.168.7.72/24 brd 192.168.7.255 scope global eth0 inet6 fe80::20c:29ff:feff:2119/64 scope link valid_lft forever preferred_lft forever-----------------------在浏览器访问该虚IP:http://192.168.7.70返回如图：证明，keepalived让haproxy1接管负载均衡，将页面跳转到apache2上
2.停掉haproxy1上的haproxy服务，5秒后keepalived会自动将其再次启动（haproxy1）# pkill haproxy等5秒# ps -ef |grep haproxy--------------root 171217080 01:17 ? 00:00:00 sh /etc/keepalived/check_haproxy.shhaproxy 2440 10 01:29 ? 00:00:00 /usr/local/haproxy/sbin/haproxy -f/usr/local/haproxy/haproxy.cfgroot 244318070 01:29 pts/1 00:00:00 grep haproxy--------------
3.停掉主的keepalived，备机马上接管服务（haproxy1）# service keepalived stop# uname -a---------------Linux ha1.example.com 2.6.32-279.el6.x86_64 #1 SMP Fri Jun 22 12:19:21 UTC 2012x86_64 x86_64 x86_64 GNU/Linux---------------（haproxy2）# ip addeth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen1000 link/ether 00:0c:29:ff:21:19 brd ff:ff:ff:ff:ff:ff inet 192.168.7.72/24 brd 192.168.7.255 scope global eth0 inet 192.168.7.70/32 scope global eth0 inet6 fe80::20c:29ff:feff:2119/64 scope link valid_lft forever preferred_lft forever# uname -a---------------Linux ha2.example.com 2.6.32-279.el6.x86_64 #1 SMP Fri Jun 22 12:19:21 UTC 2012x86_64 x86_64 x86_64 GNU/Linux---------------现已跳转到haproxy2,在浏览器再次访问该虚IP:http://192.168.7.70返回如图：
---------大功告成----------
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