http://kling.blog.51cto.com/3320545/1253474
一、前言：
在互联网上面，网站为用户提供原始的内容访问，同时为用户提供交互操作。提供稳定可靠的服务，可以给用户带来良好的体验，保证用户的正常访问使用，在网站的可靠性方面，有很多的技术可以来提供，这类技术可以分为：
高可用：保证服务的可靠，稳定，实现故障的屏蔽，避免了单点故障。
高性能：多台服务器连接起来，处理一个复杂的计算问题。
负载均衡：将用户请求引导到后端多台服务器，实现服务器请求的负载。
我们将这类技术称之为集群负载均衡，可以提供负载均衡和高可用的有硬件和软件，软件方面有haproxy，lvs，keepalived，nginx，heartbeat，corosync等等，而这里我们采用的是nginx-keepalived来构建。
Nginx有很强的代理功能，但是一台nginx 就形成了单点，现在使用keepalived来解决这个问题，keepalived可以实现故障转移切换，实现后端的健康检查，前端的高可用，使网站故障记录大大降低，避免了单点故障造成网站无法访问的问题，确保了网站业务的正常运行。
二、Nginx+keepalived有两种配置方案：
2.1、Nginx+keepalived 主从配置
这种方案，使用一个vip地址，前端使用2台机器，一台做主，一台做备，但同时只有一台机器工作，另一台备份机器在主机器不出现故障的时候，永远处于浪费状态，对于服务器不多的网站，该方案不经济实惠，所以本次不予采用。
2.2、Nginx+keepalived 双主配置
这种方案，使用两个vip地址，前端使用2台机器，互为主备，同时有两台机器工作，当其中一台机器出现故障，两台机器的请求转移到一台机器负担，非常适合于当前架构环境，故本次采用此方案对网站进行高可用架构。
三、Nginx+keepalived 主从配置
3.1、Nginx+keepalived 主从配置详情请见http://kling.blog.51cto.com/3320545/1240359
这里不做重点介绍。
四、Ningx+Keepalived 双主配置
4.1、拓扑结构
4.2、测试环境如下：
系统：Ceentos 6.4 64位
前端node1服务器：
DIP: 192.168.122.2
VIP: 192.168.122.22
前端node2服务器：
DIP: 192.168.122.3
VIP：192.168.122.23
后端服务器：
web server01：192.168.122.4
web server02：192.168.122.5
web server03：192.168.122.6
4.3、软件安装
分别在两台前端服务器上安装nginx+keepalived，使用脚本如下：
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#!/bin/bash# author: kuangl# mail: kuangl@orient-media.com# description: The installation of Nginx files.# -------------------------------------------------------- # ## Nginx_install# -------------------------------------------------------- ## Nginx installation#CURRENT_PATH=$(pwd)for i in $(rpm -q gcc gcc-c++ kernel-devel openssl-devel zlib-devel popt-devel popt-static libnl-devel wget make |grep 'not installed' | awk '{print $2}')do yum -y install $idone[ -d /root/software ][ "$?" != 0 ] && mkdir /root/softwarecd /root/software[ ! -e pcre-8.33.tar.gz ] && wget ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-8.33.tar.gztar -zxvf pcre-8.33.tar.gzcd pcre-8.33./configuremake && make installecho $? || [ $? != 0 ] || echo " installation pcre failed" || exit 1cd /root/software[ ! -e nginx-1.2.9.tar.gz ] && wget http://nginx.org/download/nginx-1.2.9.tar.gztar -zxvf nginx-1.2.9.tar.gzcd nginx-1.2.9./configure --prefix=/usr/local/nginx --with-http_ssl_module --with-http_sub_module --with-http_stub_status_module --with-http_gzip_static_modulemake && make installecho $? || [ $? != 0 ] || echo " installation nginx failed" || exit 1# -------------------------------------------------------- # ## Keepalived_intsall# -------------------------------------------------------- ## Keepalived installationcd /root/softwarae[ ! -e keepalived-1.2.4.tar.gz ] && wget http://www.keepalived.org/software/keepalived-1.2.4.tar.gztar -zxvf keepalived-1.2.4.tar.gzcd keepalived-1.2.4ln -s /usr/src/kernels/$(uname -r) /usr/src/kernels/linux./configure --prefix=/usr --bindir=/usr/bin --sbindir=/usr/bin --libexecdir=/usr/libexec --localstatedir=/var --libdir=/lib64 --infodir=/usr/share/info --sysconfdir=/etc --mandir=/usr/local/share/man --with-kernel-dir=/usr/src/kernels/linuxmake && make installecho $? || [ $? != 0 ] || print " installation keepalived failed" || exit 1chkconfig --add keepalivedchkconfig --level 345 keepalived on |
4.4、在后端服务器上安装apached
后端node4
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[root@node4 ~]# yum -y install httpd[root@node4 html]# echo "this is 192.168.122.4" > /var/www/htmlindex.html[root@node4 ~]# service httpd start[root@node4 html]# curl 192.168.122.4this is 192.168.122.4 |
后端node5
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[root@node5 ~]# yum -y install httpd[root@node5 html]# echo "this is 192.168.122.5" > /var/www/htmlindex.html[root@node5 ~]# service httpd start[root@node5 html]# curl 192.168.122.5this is 192.168.122.5 |
后端node6
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[root@node6 ~]# yum -y install httpd[root@node6 html]# echo "this is 192.168.122.6" > /var/www/htmlindex.html[root@node6 ~]# service httpd start[root@node6 html]# curl 192.168.122.6this is 192.168.122.6 |
4.5、node2、node3上配置nginx
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[root@node2 ~]# vim /usr/local/nginx/conf/nginx.confupstream web1 ##定义负载均衡组为web1 { ip_hash; server 192.168.122.4:80; server 192.168.122.5:80; server 192.168.122.6:80; } server { listen 80; server_name dev.test01.com; location / { root /home/kuangl/; index index.html index.htm; proxy_set_header Host $host; proxy_set_header X-Forwarded-For $remote_addr; proxy_pass http://web1; } } |
4.6、在node2上配置keepalived
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[root@node2 conf]# vim /etc/keepalived/keepalived.conf! Configuration File for keepalivedglobal_defs { notification_email { 404060945@qq.com } notification_email_from root@localhost smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL}vrrp_script chk_haproxy { script "/etc/keepalived/chk_nginx.sh" interval 2 weight 2}vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 200 priority 250 advert_int 1 authentication { auth_type PASS auth_pass kuanglnginx } track_script { chk_nginx } virtual_ipaddress { 192.168.122.22 }}vrrp_instance VI_2 { state BACKUP interface eth0 virtual_router_id 251 priority 100 advert_int 1 authentication { auth_type PASS auth_pass kuangl } track_script { chk_nginx } virtual_ipaddress { 192.168.122.23 }} |
4.7、在node3上配置keepalived
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! Configuration File for keepalivedglobal_defs { notification_email { 404060945@qq.com } notification_email_from root@localhost smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL}vrrp_script chk_haproxy { script "/etc/keepalived/chk_nginx.sh" interval 2 weight 2}vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 200 priority 100 advert_int 1 authentication { auth_type PASS auth_pass kuanglnginx } track_script { chk_nginx } virtual_ipaddress { 192.168.122.22 }}vrrp_instance VI_2 { state MASTER interface eth0 virtual_router_id 251 priority 250 advert_int 1 authentication { auth_type PASS auth_pass kuangl } track_script { chk_nginx } virtual_ipaddress { 192.168.122.23 }} |
4.8、在两台双主服务器上添加自动检测脚本
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#!/bin/bash# description:# 定时查看nginx是否存在，如果不存在则启动nginx# 如果启动失败，则停止keepalivedstatus=$(ps -C nginx --no-heading|wc -l)if [ "${status}" = "0" ]; then /usr/local/nginx/sbin/nginx status2=$(ps -C nginx --no-heading|wc -l) if [ "${status2}" = "0" ]; then /etc/init.d/keepalived stop fifi |
4.9、开启nginx、keepalived服务
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[root@node2 ~]# service keepalived start[root@node2 ~]# /usr/local/nginx/sbin/nginx[root@node3 ~]# service keepalived start[root@node3 ~]# /usr/local/nginx/sbin/nginx |
4.10、用 ip a 查看VIP
4.11、测试访问
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[kuangl@node01 ~]$ curl http://192.168.122.22this is 192.168.122.6[kuangl@node01 ~]$ curl http://192.168.122.22this is 192.168.122.4[kuangl@node01 ~]$ curl http://192.168.122.22this is 192.168.122.5[kuangl@node01 ~]$ curl http://192.168.122.23this is 192.168.122.6[kuangl@node01 ~]$ curl http://192.168.122.23this is 192.168.122.4[kuangl@node01 ~]$ curl http://192.168.122.23this is 192.168.122.5 |
五、后端用rsync做数据同步
node5-node6上配置进程模式，以node5为例
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[root@node5 ~]# yum -y install rsync[root@node5 ~]# vim /etc/rsynsd.confuid = rootgid = rootuse chroot = nomax connections = 5pid file = /var/run/rsyncd.pidlock file = /var/run/rsync.locklog file = /var/log/rsyncd.log[web01] path=/home/kuangl/ comment = update ignore errors read only = no list = no hosts allow = 192.168.122.0/24auth users = root uid = rootgid = rootsecrets file = /etc/rsyncd.secrets[root@node5 ~]# vim /etc/rsyncd.secretsroot:123456[root@node5 ~]# chmod 0600 /etc/rsyncd.secrets[root@node5 ~]# ll /etc/rsyncd.secrets-rw-------. 1 root root 12 Jul 20 19:41 /etc/rsyncd.secrets[root@node5 ~]# rsync --daemon[root@node5 ~]# echo "rsync --daemon" >> /etc/rc.local |
node4上配置命令模式：
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[root@node4 ~]# yum -y install rsync[root@node4 ~]# vim /etc/rsyncd.secrets123456[root@node4 ~]# chmod 0600 /etc/rsyncd.secretsroot@node4 kuangl]# rsync -vzrtopg --delete --progress --password-file=/etc/rsyncd.secrets rsync+inotify root@192.168.122.5::web01sending incremental file listrsync+inotify/rsync+inotify/inotify-tools-3.14.tar.gz 358772 100% 1.85MB/s 0:00:00 (xfer#1, to-check=2/4)rsync+inotify/rsync+inotify_client.sh 617 100% 3.11kB/s 0:00:00 (xfer#2, to-check=1/4)rsync+inotify/rsync+inotify_server.sh 900 100% 4.03kB/s 0:00:00 (xfer#3, to-check=0/4)sent 360679 bytes received 69 bytes 240498.67 bytes/sectotal size is 360289 speedup is 1.00 |
查看结果
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[root@node5 ~]# cd /home/kuangl/[root@node5 kuangl]# lltotal 8-rw-r--r--. 1 root root 22 Jul 20 15:16 index.htmldrwxr-xr-x. 2 root root 4096 Nov 11 2012 rsync+inotify |
本文出自 “&思远晨曦” 博客，请务必保留此出处http://kling.blog.51cto.com/3320545/1253474