LVS+keepalived DR模式配置高可用负载均衡集群

实验环境

LVS-Master	10.0.100.201	VIP：10.0.100.203
LVS-Slave	10.0.100.204

WEB1-Tomcat	10.0.2.29	gateway:10.0.2.253
WEB2-Tomcat	10.0.100.202

(注意：应保持所有服务器的时间一致)

Install LVS

# ln -s /usr/src/kernels/2.6.32-431.el6.i686/ /usr/src/linux
//若找不到这个目录则先安装kernel-devel
# yum -y install kernel-devel

# tar xf ipvsadm-1.24.tar.gz 

# cd /soft/ipvsadm-1.24

# make;make install

# ipvsadm -L
  IP Virtual Server version 1.2.1 (size=4096)
  Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn

Install keepalived

# tar –xvf keepalived-1.2.12.tar.gz

# ./configure --sysconf=/etc/ --with-kernel-dir=/usr/src/kernels/2.6.-.el6.i686/
Keepalived version       : 1.2.
Compiler                 : gcc
Compiler flags           : -g -O2
Extra Lib                : -lssl -lcrypto -lcrypt
Use IPVS Framework       : Yes   //表示使用ipvs框架也代表启动ipvs功能
IPVS sync daemon support : Yes   //表示启动ipvs的同步功能，--disabled-lvs-sysncd此参数可以关闭
IPVS use libnl           : No    //表示使用新的libn1版本，如果想使用新的版本，需要重新安装libn1的包
Use VRRP Framework       : Yes   //表示使用VRRP框架，这个实现keepalived高可用的必须功能
Use VRRP VMAC            : Yes   //表示使用基础VMAC接口的xmit VRRP包
SNMP support             : No
SHA1 support             : No
Use Debug flags          : No

# make;make install

# cp /soft/keepalived-1.2./bin/keepalived /usr/bin/

配置

1. LVS-Master的Keepalived配置

! Configuration File for keepalived
//全局定义
global_defs {
   notification_email     //定义邮件
   {
      xxxxxxxxx@.com    //定义邮件地址
   }
   notification_email_from xxxxxxxxx@.com
   smtp_server mail..com //定义邮件服务器
   smtp_connect_timeout   //邮件超时时间
   router_id LVS_DEVEL      //route_id标识
}

//定义VRR组
vrrp_instance VI_1 {
    state MASTER           //定义为MASTER
    interface eth0         //对外访问的网络接口
    virtual_router_id   //虚拟路由标识(注意要主从一致)
    priority            //优先级(主肯定比从高)
    nopreempt              //不抢占模式
    advert_int            //广播周期秒数
    authentication {
        auth_type PASS
        auth_pass
    }
    virtual_ipaddress {
        10.0.100.203      //VIP地址
 }
}

//VIP地址与端口等设置-->注意DR模式的VIP端口和所有WEB端口应该保持一致
virtual_server 10.0.100.203  {
    delay_loop   //健康检查时间间隔，单位秒
    lb_algo rr    //调度算法为rr
    lb_kind DR    //模式为DR
    persistence_timeout  //设置同一IP多少秒内的请求都发送到同一个realserver
    protocol TCP   //使用TCP协议

//realserver的IP与端口等设置
    real_server 10.0.2.29 {
        weight
        TCP_CHECK {
        connect_timeout    //连接超时时间，单位s
        nb_get_retry
        delay_before_retry
        connect_port       //连接端口
} 

}
    real_server 10.0.100.202  {
        weight
        TCP_CHECK {
        connect_timeout
        nb_get_retry
        delay_before_retry
        connect_port
        }
     }
}

LVS-Master：keepalived.conf

2. LVS-Slave的keepalived配置

! Configuration File for keepalived
global_defs {
   notification_email
   {
      xxxxxxxxx@.com
   }
   notification_email_from xxxxxxxxx@.com
   smtp_server mail..com
   smtp_connect_timeout
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state BACKUP      //这里的角色是BACKUP
    interface eth0
    virtual_router_id   //这里注意和MASTER保持一致
    priority            //优先级设置应比MASTER低
    advert_int
    authentication {
        auth_type PASS
        auth_pass
    }
    virtual_ipaddress {
        10.0.100.203
 }
}

virtual_server 10.0.100.203  {
    delay_loop
    lb_algo rr
    lb_kind DR
    persistence_timeout
    protocol TCP  

    real_server 10.0.2.29 {
        weight
        TCP_CHECK {
        connect_timeout
        nb_get_retry
        delay_before_retry
        connect_port
}
}
    real_server 10.0.100.202  {
        weight
        TCP_CHECK {
        connect_timeout
        nb_get_retry
        delay_before_retry
        connect_port
        }
     }
}

LVS-Slave：keepalived.conf

3. 利用脚本配置所有的WEB服务器

#!/bin/bash
# Written by NetSeek
# description: Config realserver lo and apply noarp
WEB_VIP="10.0.100.203"        //这里是VIP地址

. /etc/rc.d/init.d/functions

case "$1" in
start)
       ifconfig lo: $WEB_VIP netmask 255.255.255.255 broadcast $WEB_VIP
       /sbin/route add -host $WEB_VIP dev lo:
       echo "" >/proc/sys/net/ipv4/conf/lo/arp_ignore
       echo "" >/proc/sys/net/ipv4/conf/lo/arp_announce
       echo "" >/proc/sys/net/ipv4/conf/all/arp_ignore
       echo "" >/proc/sys/net/ipv4/conf/all/arp_announce
       sysctl -p >/dev/null >&
       echo "RealServer Start OK"
       ;;
stop)
       ifconfig lo: down
       route del $WEB_VIP >/dev/null >&
       echo "" >/proc/sys/net/ipv4/conf/lo/arp_ignore
       echo "" >/proc/sys/net/ipv4/conf/lo/arp_announce
       echo "" >/proc/sys/net/ipv4/conf/all/arp_ignore
       echo "" >/proc/sys/net/ipv4/conf/all/arp_announce
       echo "RealServer Stoped"
       ;;
status)
        # Status of LVS-DR real server.
        islothere=`/sbin/ifconfig lo: | grep $WEB_VIP`
        isrothere=`netstat -rn | grep "lo:0" | grep $web_VIP`
        if [ ! "$islothere" -o ! "isrothere" ]
        then
            echo "LVS-DR real server Stopped."
        else
            echo "LVS-DR Running."
        fi
        ;;
*)
        # Invalid entry.
        echo "$0: Usage: $0 {start|status|stop}"
        exit
        ;;
esac
exit 

realserver.sh

启动与验证

1. 在所有WEB服务器运行脚本，并查看是否都有了VIP？

WEB1:10.0.2.29
# ./realserver.sh start
RealServer Start OK
# ip add show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet 10.0.100.203/32 brd 10.0.100.203 scope global lo:0
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever

WEB2：10.0.100.202 
# ./realserver.sh start
RealServer Start OK
# ip add show
: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00::00:00:00 brd ::00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet 10.0.100.203/ brd 10.0.100.203 scope global lo:
    inet6 ::1/ scope host
       valid_lft forever preferred_lft forever

2. 在MASTER和SLAVE都启动LVS，查看VIP位置

LVS-Master:10.0.100.201
# /etc/init.d/keepalived start
正在启动 keepalived：                                      [确定]
# ip add show
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu  qdisc pfifo_fast state UNKNOWN qlen
    link/ether 00:0c:29:0f:bf:4a brd ff:ff:ff:ff:ff:ff
    inet 10.0.100.201/16 brd 10.0.255.255 scope global eth0
    inet 10.0.100.203/32 scope global eth0
    inet6 fe80::20c:29ff:fe0f:bf4a/64 scope link
       valid_lft forever preferred_lft forever

LVS-Slave:10.0.100.204
# /etc/init.d/keepalived start
正在启动 keepalived：                                      [确定]
# ip add show
: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu  qdisc pfifo_fast state UNKNOWN qlen
    link/ether :0c::2e:1d:0d brd ff:ff:ff:ff:ff:ff
    inet 10.0.100.204/16 brd 10.0.255.255 scope global eth0
    inet6 fe80::20c:29ff:fe2e:1d0d/ scope link
       valid_lft forever preferred_lft forever

3. 访问测试(可通过浏览器访问VIP，我们测试是否在两个实验WEB服务器访问中实现了负载均衡)

LVS-Master:10.0.100.201
# ipvsadm -L
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  10.0.100.203:http rr
  -> 10.0.100.202:http            Route   1      0          0
  -> 10.0.2.29:http               Route   1      0          0  

LVS-Slave:10.0.100.204
# ipvsadm -L
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  10.0.100.203:http rr
  -> 10.0.100.202:http            Route   1      0          0
  -> 10.0.2.29:http               Route   1      0          0