centos7以tomcat为例用keepalived的LVS做负载均衡

你的名字 2022-06-04 00:24 176阅读 0赞

keepalived可以用来做双机热备，此外它还有一个LVS模块可以用来做负载均衡，不过功能没有nginx强大，主要是看用途自己结合了。我用两台keepalived主备机，和三台tomcat服务机做测试。  
安装keepalived无特殊要求的话，直接用简单的yum安装即可：`yum -y install keepalived` 安装好后 `vi /etc/keepalived/keepalived.conf` 来配置keepalived的主机（格式要对，有些空格不能少）：

global_defs { router_id one }
    vrrp_instance VI_1 { state MASTER interface enp0s8 virtual_router_id 60 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 }
    
        virtual_ipaddress { 192.168.56.100 }
    }
    
    virtual_server 192.168.56.100 8080 { delay_loop 6 lb_algo rr lb_kind DR nat_mask 255.255.255.0 persistence_timeout 50 protocol TCP real_server 192.168.56.34 8080 { weight 1 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 8080 }
        }
    
         real_server 192.168.56.35 8080 { weight 1 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 8080 }
      }
    
         real_server 192.168.56.36 8080 { weight 1 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 8080 }
         }
    }

然后同样的路径去配置备机：

global_defs { router_id two }
    vrrp_instance VI_1 { state BACKUP interface enp0s8 virtual_router_id 60 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 1111 }
    
        virtual_ipaddress { 192.168.56.100 }
    }
    
    virtual_server 192.168.56.100 8080 { delay_loop 6 lb_algo rr lb_kind DR persistence_timeout 50 protocol TCP real_server 192.168.56.34 8080 { weight 1 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 8080 }
    
        }
    
         real_server 192.168.56.35 8080 { weight 1 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 8080 }
         }
    
         real_server 192.168.56.36 8080 { weight 1 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 8080 }
         }
    }

然后再去三台tomcat服务器将tomcat部署好，如果想要在接受到虚拟ip的请求后返回数据，还需要配置一个脚本：

[root@four ~]# vi realserver.sh 
    
    #add for chkconfig
    #chkconfig: 2345 70 30
    #description: RealServer's script
    #processname: realserver.sh
    #!/bin/bash
    VIP=192.168.56.100
    source /etc/rc.d/init.d/functions
    case "$1" in
    start)
           ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP
           /sbin/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
           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

然后赋予权限启动它就可以了！可以在keepalived中使用ipvsadm看到！