Chinaunix首页 | 论坛 | 博客
  • 博客访问: 35828
  • 博文数量: 4
  • 博客积分: 2955
  • 博客等级: 少校
  • 技术积分: 38
  • 用 户 组: 普通用户
  • 注册时间: 2009-07-21 14:48
文章分类

全部博文(4)

文章存档

2010年(2)

2009年(2)

最近访客

分类: LINUX

2009-07-21 14:49:53

操作系统平台:CentOS5.2
软件:LVS+keepalived
 
LVS+Keepalived 介绍
LVS
LVS是Linux Virtual Server的简写,意即Linux虚拟服务器,是一个虚拟的服务器集群系统。本项目在1998年5月由章文嵩博士成立,是中国国内最早出现的自由软件项目之一。目前有三种IP负载均衡技术(VS/NAT、VS/TUN和VS/DR);
十种调度算法(rrr|wrr|lc|wlc|lblc|lblcr|dh|sh|sed|nq)。
Keepalvied
Keepalived在这里主要用作RealServer的健康状态检查以及LoadBalance主机和BackUP主机之间failover的实现
 
 
IP配置信息:
  1. LVS-DR-Master          192.168.2.166
  2. LVS-DR-BACKUP          192.168.2.167
  3. LVS-DR-VIP             192.168.2.170       
  4. WEB1-Realserver        192.168.2.171
  5. WEB2-Realserver        192.168.2.172
  6. GateWay                192.168.2.253

安装LVS和Keepalvied软件包
   

1. 下载相关软件包

#mkdir /usr/local/src/lvs

#cd /usr/local/src/lvs

#wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz

#wget http://www.keepalived.org/software/keepalived-1.1.15.tar.gz

 

2. 安装LVS和Keepalived

  1. #lsmod |grep ip_vs
  2. #uname -r
  3. 2.6.18-53.el5PAE
  4. #ln -s /usr/src/kernels/2.6.18-53.el5PAE-i686/  /usr/src/linux

  5. #tar zxvf ipvsadm-1.24.tar.gz
  6. #cd ipvsadm-1.24
  7. #make && make install
  8. #find / -name ipvsadm  # 查看ipvsadm的位置

  9. #tar zxvf keepalived-1.1.15.tar.gz
  10. #cd keepalived-1.1.15
  11. #./configure  && make && make install
  12. #find / -name keepalived  # 查看keepalived位置               
  13.    
  14. #cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
  15. #cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
  16. #mkdir /etc/keepalived
  17. #cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
  18. #cp /usr/local/sbin/keepalived /usr/sbin/
  19. #service keepalived start|stop     #做成系统启动服务方便管理.
四. 配置LVS实现负载均衡

  1. LVS-DR,配置LVS脚本实现负载均衡
 
vi /usr/local/sbin/lvs-dr.sh
 
#!/bin/bash
# description: start LVS of DirectorServer
#Written by :NetSeek http://www.linuxtone.org
GW=192.168.2.253
 
# website director vip.
WEB_VIP=192.168.2.170
WEB_RIP1=192.168.2.171
WEB_RIP2=192.168.2.172

. /etc/rc.d/init.d/functions
 
logger $0 called with $1
 
case "$1" in
 
start)
        # Clear all iptables rules.
        /sbin/iptables -F
        # Reset iptables counters.
        /sbin/iptables -Z
        # Clear all ipvsadm rules/services.
        /sbin/ipvsadm -C
 
 #set lvs vip for dr
        /sbin/ipvsadm --set 30 5 60
        /sbin/ifconfig eth0:0 $WEB_VIP broadcast $WEB_VIP netmask 255.255.255.255 up
        /sbin/route add -host $WEB_VIP dev eth0:0
        /sbin/ipvsadm -A -t $WEB_VIP:80 -s wrr -p 3
        /sbin/ipvsadm -a -t $WEB_VIP:80 -r $WEB_RIP1:80 -g -w 1
        /sbin/ipvsadm -a -t $WEB_VIP:80 -r $WEB_RIP2:80 -g -w 1
        touch /var/lock/subsys/ipvsadm >/dev/null 2>&1
       
        # set Arp
        /sbin/arping -I eth0 -c 5 -s $WEB_VIP $GW >/dev/null 2>&1
       ;;
stop)
        /sbin/ipvsadm -C
        /sbin/ipvsadm -Z
        ifconfig eth0:0 down
        route del $WEB_VIP  >/dev/null 2>&1
        rm -rf /var/lock/subsys/ipvsadm >/dev/null 2>&1
        /sbin/arping -I eth0 -c 5 -s $WEB_VIP $GW
        echo "ipvsadm stoped"
       ;;
 
status)
 
        if [ ! -e /var/lock/subsys/ipvsadm ];then
                echo "ipvsadm is stoped"
                exit 1
        else
                ipvsadm -ln
                echo "..........ipvsadm is OK."
        fi
      ;;
 
*)
        echo "Usage: $0 {start|stop|status}"
        exit 1
esac
 
exit 0
2. 配置Realserver脚本.
 

#!/bin/bash
# Written by NetSeek
# description: Config realserver lo and apply noarp
WEB_VIP=192.168.2.170
 
. /etc/rc.d/init.d/functions
 
case "$1" in
start)
       ifconfig lo:0 $WEB_VIP netmask 255.255.255.255 broadcast $WEB_VIP
       /sbin/route add -host $WEB_VIP dev lo:0
       echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
       echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
       echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
       echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
       sysctl -p >/dev/null 2>&1
       echo "RealServer Start OK"
 
       ;;
stop)
       ifconfig lo:0 down
       route del $WEB_VIP >/dev/null 2>&1
       echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
       echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
       echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
       echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
       echo "RealServer Stoped"
       ;;

status)
        # Status of LVS-DR real server.
        islothere=`/sbin/ifconfig lo:0 | grep $WEB_VIP`
        isrothere=`netstat -rn | grep "lo:0" | grep $web_VIP`
        if [ ! "$islothere" -o ! "isrothere" ];then
            # Either the route or the lo:0 device
            # not found.
            echo "LVS-DR real server Stopped."
        else
            echo "LVS-DR Running."
        fi
;;
*)
        # Invalid entry.
        echo "$0: Usage: $0 {start|status|stop}"
        exit 1
;;
esac
exit 0

 
附上realserver机上的/etc/sysctl.conf:
 

# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled.  See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls IP packet forwarding
net.ipv4.ip_forward = 1

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1

# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0

# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2

或者采用secondary ip address方式配置
# vi /etc/sysctl.conf
 
添加以下内容如上所示:
 

net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2

 #sysctl –p
 #ip addr add 61.164.122.8/32 dev lo
 #ip add list 查看是否绑定

 3. 启动lvs-dr脚本和realserver启本,在DR上可以查看LVS当前状态:

 #watch ipvsadm –ln

 

五.利用Keepalvied实现负载均衡和和高可用性

1.配置在主负载均衡服务器上配置keepalived.conf

#vi /etc/keepalived/keepalived.conf (主调度器)

! 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 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.2.170
    }
}

virtual_server 192.168.2.170 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    persistence_timeout 60
    protocol TCP
  
    real_server 192.168.2.171 80 {
        weight 3            
        TCP_CHECK {
        connect_timeout 10  
        nb_get_retry 3
        delay_before_retry 3
        connect_port 80
 } 
    }

    real_server 192.168.2.172 80 {
        weight 3
        TCP_CHECK {
        connect_timeout 10
        nb_get_retry 3
        delay_before_retry 3
        connect_port 80

        }

     }

}

 

在备用调度器上:

#vi /etc/keepalived/keepalived.conf (备用调度器)

! 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 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.2.170
    }
}

virtual_server 192.168.2.170 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    persistence_timeout 60
    protocol TCP
  
    real_server 192.168.2.171 80 {
        weight 3            
        TCP_CHECK {
        connect_timeout 10  
        nb_get_retry 3
        delay_before_retry 3
        connect_port 80
 } 
    }

    real_server 192.168.2.172 80 {
        weight 3
        TCP_CHECK {
        connect_timeout 10
        nb_get_retry 3
        delay_before_retry 3
        connect_port 80

        }

     }

}

 

2. BACKUP服务器同上配置,先安装lvs再按装keepalived,仍后配置/etc/keepalived/keepalived.conf,只需将红色标示的部分改一下即可.

3. vi /etc/rc.local
   #/usr/local/sbin/lvs-dr.sh  将lvs-dr.sh这个脚本注释掉。
   #/usr/local/sbin/lvs-dr.sh stop 停止lvs-dr脚本

   #/etc/init.d/keepalived start  启动keepalived 服务,keepalived就能利用keepalived.conf 配
   置文件,实现负载均衡和高可用.

4. 查看lvs服务是否正常
  

#watch ipvsadm –ln

IP Virtual Server version 1.2.1 (size=4096)

Prot LocalAddressort Scheduler Flags

  -> RemoteAddressort           Forward Weight ActiveConn InActConn

TCP  61.164.122.8:80 wrr persistent 60

  -> 61.164.122.10:80            Route   3      0          0

  -> 61.164.122.9:80             Route   3      0          0

复制代码

#tail –f /var/log/message  监听日志,查看状态,测试LVS负载均衡及高可用性是否有效。

5.停Master服务器的keepalived服务,查看BAKCUP服务器是否能正常接管服务。


四.相关参考

1.LVS 基础知识汇总


LVS的算法介绍            http://www.linuxtone.org/viewthread.php?tid=69
学习LVS的三种转发模式     http://www.linuxtone.org/viewthread.php?tid=77
LVS中的IP负载均衡技术     http://www.linuxtone.org/viewthread.php?tid=68

更多的请到http://www.linuxtone.org 负载均衡版查看

Keepalived 相关参考资料。
   http://www.keepalived.org/documentation.html

阅读(2318) | 评论(0) | 转发(2) |
给主人留下些什么吧!~~
评论热议
请登录后评论。

登录 注册