基于VMware的虚拟Linux集群搭建-lvs+keepalived本文通过keepalived实现lvs服务器的的双机热备和真实服务器之间的负载均衡。这方面的blog挺多，但是每个人搭建集群的环境不同，遇到的问题也不同，本文简述配置的一些过程以及配置过程中遇到问题时的解决方案。准本工作1. 创建Linux虚拟机本文是基于Vmare虚拟环境搭建集群的，所以首先在Vmare中创建一些虚拟机（安装一个Linux系统，其他的复制第一次安装的即可），本文创建4台虚拟机。网卡模式设置成桥接方式，这样可以保证虚拟机中的网络和主机IP在同一个网段，这样的好处是，给每台虚拟机设完IP之后，就可以通过同一网段的另一台主机登陆到Linux，就不用在虚拟机之间来回切换了。（Linux发行版本为CentOS 5.5）2. 配置yum库
若本机没有yum库，最好配置安装yum库，方便软件的安装
yum库创建基本步骤
①安装createrepo
②yum -y installl createrepo
③用createrepo创建
createrepo命令用于生成yum仓库所需要的一些基本配置信息。
具体请参考“yum库的安装于配置”
集群配置1. 设置虚拟机IP
在Vmare虚拟机中虚拟四个Linux主机
LvsMaster：192.168.10.101
LvsBak: 192.168.10.102
RealServer1: 192.168.10.121
RealServer2: 192.168.10.122
主机之间的拓扑关系图
2. 安装ipvsadm 和 keepalived① 分别在LvsMaster和LvsBak上安装 ipvsadm
yum -y install *ipvsadm*
下载地址：wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar
②分别在LvsMaster和LvsBak上安装 keepalived
安装依赖库：yum install -y openssl openssl-devel
下载keepalived：wget http://www.keepalived.org/software/keepalived-1.2.6.tar.gz
tar zxvf keepalived-1.2.6.tar.gz./configure –prefix=/usr/local/keepalivedmakemake installcp /usr/local/keepalived/sbin/keepalived /usr/sbin/cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/mkdir /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/keepalived /etc/keepalived.conf
③ 配置 keepalived
LvsMaster配置
global_defs { notification_email { 540621626@qq.com #emial通知 } notification_email_from 540621626@qq.com smtp_server 192.168.200.1 smtp_connect_timeout 30 router_id LVS_DEVEL}vrrp_sync_group test { #设置vrrp组group {loadbalance}}vrrp_instance loadbalance { state MASTER #设置主机类型，MASTER和BACKUP两种，必须大写，即太主机一台备用机 interface eth0#设置对外服务网卡 virtual_router_id 51 priority 100 #设置优先级，备用主机的优先级要比主机低即可 advert_int 1#设置同步时间间隔 authentication {#设置验证类型和密码 auth_type PASS auth_pass 1111 } virtual_ipaddress {#设置虚拟ip，即浮动ip 192.168.10.115 }virtual_server 192.168.10.115 80 { delay_loop 6#健康检查时间间隔 lb_algo rr#负载调度算法，默认为轮训算法 lb_kind DR#负载均衡转发规则，也就是IP转发规则，DR转发方式最快，但是所有机器必须在一个网段内，还有NAT和TUNEL两种转发方式 protocol TCP real_server 192.168.10.121 80 { weight 1 TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.10.122 80 { weight 1TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3}}
}
LvsBakr配置
global_defs { notification_email { 540621626@qqq.com } notification_email_from 540621626@qq.com smtp_server 192.168.200.1 smtp_connect_timeout 30 router_id LVS_DEVEL}vrrp_sync_group test {group {loadbalance}}
vrrp_instance loadbalance { state BACKUP interface eth0 virtual_router_id 51 priority 99 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.10.115 }}virtual_server 192.168.10.115 80 { delay_loop 6 lb_algo rr lb_kind DR protocol TCP real_server 192.168.10.121 80 { weight 1 TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.10.122 80 { weight 1TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3} }}
④ 启动keepalived
LvsMastrer:/etc/init.d/keepalived start
LvsBak : /etc/init.d/keepalived start
查看启动状态
LvsMaster: tail -f /var/log/messages
LvsBak: tail -f /var/log/messages
用ip addr和ipvsadm查看路由情况
LvsMaster： ip addr
LvsMaster: ipvsadm
LvsBak：ip addr
LvsBak：ipvsadm
3. 设置RealServer1和RealServer2① 编辑RealServe脚本RealServer1和ResalServer2的脚本设置相同，都是realserver.sh，设置脚本如下SNS_VIP=192.168.10.115source /etc/rc.d/init.d/functionscase "$1" instart)ifconfig lo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP up/sbin/route add -host $SNS_VIP dev lo:0echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/lo/arp_announceecho "1" >/proc/sys/net/ipv4/conf/all/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/all/arp_announcesysctl -p >/dev/null 2>&1echo "RealServer Start OK";;stop)ifconfig lo:0 downroute del $SNS_VIP >/dev/null 2>&1echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignoreecho "0" >/proc/sys/net/ipv4/conf/lo/arp_announceecho "0" >/proc/sys/net/ipv4/conf/all/arp_ignoreecho "0" >/proc/sys/net/ipv4/conf/all/arp_announceecho "RealServer Stoped";;*) echo "Usage: $0 {start|stop}" exit 1esacexit 0脚本编辑完成后启动realserver.shRealServer1： ./realserver.sh startRealServer2： ./realserver.sh start查看IP② 在RealServer1和RealServer2上安装apache安装yum -y install httpd配置ServerName www.example.comNameVirtualHost 192.168.10.121:80<VirtualHost 192.168.10.121:80>DocumentRoot /var/www/htmlServerName www.example.com</VirtualHost>在 /var/www/hmtl/下添加index.html测试主页启动apache ：/etc/init.d/httpd start4. 测试负载均衡和双机热备用ipvsadm查看 LvsMaster 和 LvsBak的路由情况LvsMaster: ipvsadmLvsBak: ipvsadm
5. 配置过程中应注意的问题① 配置keepalvied应注意的问题LvsMaster和LvsBak只有两处不同state MASTER | BACKUP （主Lvs是MASTER，备用Lv是BACKUP）priority 100 | 90 （主Lvs是100，备用LVS只要小于100即可）② 要关闭iptables或者开启相应的服务端口，否则无法通过浏览器访问你会发现，曾经以为很难做到的事情，
