LVS+Keepalived 实现高性能高可用负载均衡服务器

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

1. LVS-DR-Master        61.164.122.6        
   

2. LVS-DR-BACKUP        61.164.122.7        
   

3. LVS-DR-VIP        61.164.122.8        
   

4. WEB1-Realserver        61.164.122.9        
   

5. WEB2-Realserver        61.164.122.10        
   

6. GateWay        61.164.122.1   

安装LVS和Keepalvied软件包
下载相关软件包

1.      #mkdir /usr/local/src/lvs
   

2.      #cd /usr/local/src/lvs
   

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

4.      #wgethttp://www.keepalived.org/software/keepalived-1.1.15.tar.gz

 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. 
   

6.         #tar zxvf ipvsadm-1.24.tar.gz
   

7.         #cd ipvsadm-1.24
   

8.         #make && make install
   

9.         #find / -name ipvsadm  # 查看ipvsadm的位置
   

10. 
    

11.         #tar zxvf keepalived-1.1.15.tar.gz
    

12.         #cd keepalived-1.1.15
    

13.         #./configure  && make && make install
    

14.         #find / -name keepalived  # 查看keepalived位置               
    

15. 
    

16.         #cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
    

17.         #cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
    

18.         #mkdir /etc/keepalived
    

19.         #cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
    

20.         #cp /usr/local/sbin/keepalived /usr/sbin/
    

21.         #service keepalived start|stop     #做成系统启动服务方便管理.

 配置LVS实现负载均衡
  vi /etc/sysctl.conf

1.           net.ipv4.conf.lo.arp_ignore = 1
   

2.           net.ipv4.conf.lo.arp_announce = 2
   

3.           net.ipv4.conf.all.arp_ignore = 1
   

4.           net.ipv4.conf.all.arp_announce = 2

5.           sysctl   -p

       ip addr add 61.164.122.8/32 dev lo

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

1.   ! Configuration File for keepalived
   

2. 
   

3. global_defs {
   

4.    notification_email {
   

5.          [email protected]

6.    }
   

7.    notification_email_from [email protected]
   

8.    smtp_server 127.0.0.1
   

9.   # smtp_connect_timeout 30
   

10.    router_id LVS_DEVEL
    

11. }
    

12. 
    

13. # 20081013 written by :netseek
    

14. # VIP1
    

15. vrrp_instance VI_1 {
    

16.     state MASTER             #备份服务器上将MASTER改为BACKUP   
    

17.     interface eth0
    

18.     virtual_router_id 51
    

19.     priority 100    # 备份服务上将100改为99
    

20.     advert_int 1
    

21.     authentication {
    

22.         auth_type PASS
    

23.         auth_pass 1111
    

24.     }
    

25.     virtual_ipaddress {
    

26.         61.164.122.8   
    

27.         #(如果有多个VIP，继续换行填写.)
    

28.     }
    

29. }
    

30. 
    

31. virtual_server 61.164.122.8 80 {
    

32.     delay_loop 6                  #(每隔10秒查询realserver状态)
    

33.     lb_algo wrr                  #(lvs 算法)
    

34.     lb_kind DR                  #(Direct Route)
    

35.     persistence_timeout 60        #(同一IP的连接60秒内被分配到同一台realserver)
    

36.     protocol TCP                #(用TCP协议检查realserver状态)
    

37. 
    

38.     real_server 61.164.122.9 80 {
    

39.         weight 3               #(权重)
    

40.         TCP_CHECK {
    

41.         connect_timeout 10       #(10秒无响应超时)
    

42.         nb_get_retry 3
    

43.         delay_before_retry 3
    

44.         connect_port 80
    

45.         }
    

46.     }
    

47.     real_server 61.164.122.10 80 {
    

48.         weight 3
    

49.         TCP_CHECK {
    

50.         connect_timeout 10
    

51.         nb_get_retry 3
    

52.         delay_before_retry 3
    

53.         connect_port 80
    

54.         }
    

55.      }
    

56. }
    

#/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.
     整个LVS负均衡HA方案，由keepalived.conf一个文件即可搞定！