lvs+keepalived+nginx

安装过程

查看是否有ipvsadm软件

1. 检查ipvsadm是否安装成功，可以直接输入，使用rpm包安装ipvsadm会比源码安装简单很多，
下载ipvsadm-1.24-13.el5.x86_64.rpm，执行rpm -ivh ipvsadm-1.24-13.el5.x86_64.rpm
[root@localhost ~]# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port Forward Weight ActiveConn InActConn
 
2. 检查模版是否加入内核
[root@localhost ~]# lsmod |grep ip_vs
 ip_vs 78081 0 
 如果没有显示，则说明没有加载，执行命令modprobe ip_vs就可以把ip_vs模块加载到内核

安装keepalived

1. keepalived-1.2.1.tar.gz     # 解压这个文件并且安装 (tar -zxvf keepalived-1.2.1.tar.gz)
2. ./configure --prefix=/hnisi/local/keepalived/ --with-kernel-dir=/usr/src/kernels/2.6.18-164.el5-i686
3.make
4.make install
5.配置文件的路径
cp /hnisi/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
cp /hnisi/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp /hnisi/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
cp /hnisi/local/keepalived/sbin/keepalived /sbin/

配置主keepalived

! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 88
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 85574999
    }
    virtual_ipaddress {
        192.168.22.250
    }
}

virtual_server 192.168.22.250 9082 {
    delay_loop 3
    lb_algo rr
    lb_kind DR
    protocol TCP
    
    real_server 192.168.22.237 9082 {
      weight 3
      TCP_CHECK {
        connect_timeout 10
        nb_get_retry 3
        delay_before_retry 3
        connect_port 9082
      }
    }

    real_server 192.168.22.229 9082 {
      weight 1
      TCP_CHECK {
        connect_timeout 10
        nb_get_retry 3
        delay_before_retry 3
        connect_port 9082
      }
    }

}

配置备keepalived

! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 30
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 85574999
    }
    virtual_ipaddress {
        192.168.22.250
    }
}

virtual_server 192.168.22.250 9082 {
    delay_loop 3
    lb_algo rr
    lb_kind DR
    protocol TCP
    
    real_server 192.168.22.237 9082 {
      weight 3
      TCP_CHECK {
        connect_timeout 10
        nb_get_retry 3
        delay_before_retry 3
        connect_port 9082
      }
    }

    real_server 192.168.22.229 9082 {
      weight 1
      TCP_CHECK {
        connect_timeout 10
        nb_get_retry 3
        delay_before_retry 3
        connect_port 9082
      }
    }

}

分别在主备上启动keepalived

[root@ip_lb home]# /etc/init.d/keepalived start
Starting keepalived: [  OK  ]

[root@ip_lb home]# /etc/init.d/keepalived stop
Stoping keepalived: [  OK  ]

[root@ip_lb home]# tail -f /var/log/messages

# PS:这里说的LVS，并不是用ipvsadm软件配置，而是直接用keepalived的virtual_server配置项控制的。
# 安装ipvsadm只是可以看到负载状况，其实只需要keepalived也可以实现负载均衡集群。

在web1服务器配置LVS-DR

vim /etc/init.d/lvsDR_node（web1主机）

#! /bin/sh   
# descript : start real server DR  
VIP=192.168.96.100  
. /etc/rc.d/init.d/functions  
case "$1" in  
       start)  
             echo "start LVS of RealServer DR"  
             /sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up  
             echo "1" > /proc/sys/net/ipv4/conf/all/arp_ignore  
             echo "2" > /proc/sys/net/ipv4/conf/all/arp_announce  
               ;;  
       stop)  
             /sbin/ifconfig lo:0 down  
             echo "close LVS of RealServer DR"  
             echo "0" > /proc/sys/net/ipv4/conf/all/arp_ignore  
             echo "0" > /proc/sys/net/ipv4/conf/all/arp_announce  
              ;;  
         *)  
              echo "Usage : $0 {start|stop}"  
              exit 1  
esac  

把这个文件复制到web2主机上

在web1和web2上分别启动这个脚本:

/etc/init.d/lvsDR_node start

测试是否可以负载均衡

#! /bin/sh  
for((i=1;i<=100;i++));do   
curl http://192.168.96.100:8099 >> /tmp/q;  
done  

官方文档：http://www.keepalived.org/pdf/sery-lvs-cluster.pdf

相关阅读：http://www.cnblogs.com/liwei0526vip/p/6370103.html