lvs+keepalived实现Mycat的负载均衡--高可用

上一篇的mysql主备已经完成，但是mycat只在130主上有一个，接下来在140master2上通过docker运行一个一模一样的mycat,就可以来配置lvs+keepalived了。

1. 再准备两台虚拟机150（keepalived主），151(keepalived从)
2. 下载安装keepalived ipvsadm 执行

   yum install keepalived ipvsadm
   cp /etc/keepalived/keepalived.conf $PWD/keepalived.conf.bak
   vim /etc/keepalived/keepalived.conf
   
   

   keepalived.conf内容：（主）

   ! 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 51
       priority 100
       advert_int 1
       authentication {
           auth_type PASS
           auth_pass 1111
       }
       virtual_ipaddress {
           192.168.209.100/24 dev eth0 label eth0:3
       }
   }
   
   virtual_server 192.168.209.100 8066 { 
       delay_loop 6
       lb_algo rr
       lb_kind DR
       nat_mask 255.255.255.0
       persistence_timeout 0
       protocol TCP
   
   
   
       real_server 192.168.209.130 8066 {
   
                 weight 1
            TCP_CHECK {
               connect_timeout 10
               nb_get_retry 3
               delay_before_retry 3
           }
   
       }
   
    real_server 192.168.209.140 8066 {
   
           weight 1
               TCP_CHECK {
               connect_timeout 10
               nb_get_retry 3
               delay_before_retry 3
           }
   
   
       }
   
   
   }

   virtual_server端口必须与real_server端口一样是8066 否则无法通过vip连接mycat

   
   keepalived.conf内容：（备）

   ! 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 52
       priority 90
       advert_int 1
       authentication {
           auth_type PASS
           auth_pass 1111
       }
       virtual_ipaddress {
           192.168.209.100/24 dev eth0 label eth0:3
       }
   }
   
   virtual_server 192.168.209.100 8066 {
       delay_loop 6
       lb_algo rr
       lb_kind DR
       nat_mask 255.255.255.0
       persistence_timeout 0
       protocol TCP
   
       real_server 192.168.209.130 8066 {
   
                 weight 1
            TCP_CHECK {
               connect_timeout 10
               nb_get_retry 3
               delay_before_retry 3
           }
   
       }
   
    real_server 192.168.209.140 8066 {
   
           weight 1
               TCP_CHECK {
               connect_timeout 10
               nb_get_retry 3
               delay_before_retry 3
           }
   
   
       }
   }

   配置完成后启动keepalived:

   service keepalived start

3. 将这两台 Mycat 服务器都配置成 lvs 的 real server，编辑 realserver 脚本文件：vim /etc/init.d/realserver
   然后在两台mycat中执行以下脚本内容：
   

   #!/bin/bash
   
   VIP=192.168.209.100
   
   /etc/rc.d/init.d/functions
   
   case "$1" in
   start)
          ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP
          route add -host $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 $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"
          ;;
   *)
          echo "Usage: $0 {start|stop}"
          exit 1
   esac
   
   exit 0

   保存脚本文件后更改该文件权限：chmod -R 755 /etc/init.d/realserver 

   同时再更改 functions 文件权限：chmod -R 755 /etc/init.d/functions

   首先启动 mysql，接着启动 mycat，然后启动 realserver（./realserver start），再启动 keepalived
   
   
4. 测试高可用：
   关掉130（mysql01 和mycat01）
   
   
   
   开启130关掉150（keepalived主）
   
   

　　　　无论哪种情况，通过sqlyog连接192.168.209.100:8066 服务均可用，即实现了mysql集群高可用