实现基于keepalived高可用集群

时间:2021-03-02 01:29:29

实现基于keepalived高可用集群

    keepalived主要模块是VRRP Stack和Cheackers,实现HA集群中失败切换(Failover)功能。Keepalived通过VRRP功能能再结合LVS负载均衡软件即可部署一个高性能的负载均衡集群系统。,Cheackers主要实现对服务器运行状态检测和故障隔离。其中ipvs和realserver健康状态检查通过配置文件配置就可以实现,而其他服务高可用则需要通过自己编写脚本,然后配置keepalived调用来实现。

   Keepalived运行有3个守护进程。父进程主要负责读取配置文件初始化、监控2个子进程等;然后两个子进程,一个负责VRRP,另一个负责Cheackers健康检查。其中父进程监控模块为WacthDog,工作实现:每个子进程打开一个接受unix域套接字,父进程连接到那些unix域套接字并向子进程发送周期性(5s)hello包。

   VRRP(Virtual Router Redundancy Protocol,虚拟路由冗余协议)可以认为是实现路由器高可用的协议,简单的说,当一个路由器故障时可以由另一个备份路由器继续提供相同的服务。

   VRRP根据优先级来确定虚拟路由器中每台路由器的角色(Master路由器或Backup路由器)。VRRP优先级的取值范围为0到255(数值越大表明优先级越高),可配置的范围是1到254,优先级0为系统保留给路由器放弃Master位置时候使用,255则是系统保留给IP地址拥有者使用。优先级越高,则越有可能成为Master路由器。当两台优先级相同的路由器同时竞争Master时,比较接口IP地址大小。接口地址大者当选为Master。


实验一、主从模式的集群服务(基于DR集群工作模式)

实现基于keepalived高可用集群

1、准备四台主机:都是桥接模式

      一台Director-master,DIP:172.17.111.117 VIP:172.17.111.111

        一台Director-backup,DIP:172.17.222.220 VIP:172.17.111.111

      一台后台服务器,RIP:172.17.111.234 VIP:172.17.111.111

      一台后台服务器,RIP:172.17.111.222 VIP:172.17.111.111

2、Director-master上操作:

              ①安装keepalived服务:

                 yum install keepalived

              ②修改配置文件:

                 vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

 global_defs {

   notification_email {

     root@localhost   邮件接收者

   }

   notification_email_from Alexandre.Cassen@firewall.loc 发件人

   smtp_server 127.0.0.1   发邮件的服务器

   smtp_connect_timeout 2   连接超时时间

   router_id LVS_DEVEL     路由器的标识

}

 vrrp_instance VI_1 {       配置虚拟路由器的实例

    state MASTER        初始状态

    interface eth0       所用端口

    virtual_router_id 50   虚拟路由的ID号

#    nopreempt 非抢占式,当多个BACKUP时,其中有个BACKUP的优先级高但是为非抢占式,那么它就不去抢VIP。

    priority 100        优先级

    advert_int 1        VRRP通告间隔

 authentication {         认证机制

        auth_type PASS

        auth_pass 1111

    }

    virtual_ipaddress {

        172.17.111.111

    }

}

 

virtual_server 172.17.111.111 80 {   虚拟服务

    delay_loop 6            服务轮询的时间间隔

    lb_algo wrr          LVS调度算法

    lb_kind DR             LVS集群模式

    nat_mask 255.255.255.255

    persistence_timeout 50       会话保持时间

    protocol TCP              健康检查用的协议

 

    real_server 172.17.111.222 80 { 后端真实节点主机

        weight 1         权重

        HTTP_GET {

            url {

              path /

            }

            connect_timeout 3   连接超时时间

            nb_get_retry 3     重连次数

            delay_before_retry 3 重连间隔

        }

    }

    real_server 172.17.111.234 80 {

        weight 1

        HTTP_GET {

            url {

              path /

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }   

    }

}

     ③开启转发功能

               echo 1 >/proc/sys/net/ipv4/ip_forward

     ④启动服务

            systemctl start keepalived

 

3、Director-backup上操作:

           ①安装keepalived服务:

                 yum install keepalived

           ②修改配置文件:

                 vim /etc/keepalived/keepalived.conf  

           同master的配置文件,只是修改一下初始状态及优先级即可

                    state BACKUP

                    priority 90    

           

           ③开启转发功能

               echo 1 >/proc/sys/net/ipv4/ip_forward

           ④启动服务

            systemctl start keepalived


4、两个后台服务器上操作:

          ①配置回环网卡:

  ifconfig lo:0 172.17.111.111 broadcast 172.17.111.111 netmask 255.255.255.255 up

            route add -host 172.17.111.111 lo:0

          ②忽略ip与mac不匹配的问题:

            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

5、测试:刚启动服务查看ip是在MASTER上,当关闭MASTER上的keepalived服务,那么ip就被BACKUP拿走了

实现基于keepalived高可用集群 


实验二、双主模式的集群服务(基于DR集群工作模式):

实现基于keepalived高可用集群

1、准备四台主机:都是桥接模式

     一台Director-master,DIP:172.17.111.117                                          VIP1:172.17.111.111 

               VIP2:172.17.111.112

     一台Director-backup,DIP:172.17.222.220 

               VIP1:172.17.111.111

               VIP2:172.17.111.112

     一台后台服务器,RIP:172.17.111.234 

            VIP1:172.17.111.111 

            VIP2:172.17.111.112

     一台后台服务器,RIP:172.17.111.222 

            VIP1:172.17.111.111 

            VIP2:172.17.111.112

2、Director-master1上操作:

         ①安装keepalived服务:

                  yum install keepalived

            ②修改配置文件(具体代码含义请参看上面的实验):

                  vim /etc/keepalived/keepalived.cong

! Configuration File for keepalived

 global_defs {

   notification_email {

     root@localhost

   }

   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 50

#    nopreempt

    priority 100

    advert_int 1

 authentication {

        auth_type PASS

        auth_pass 1111

    }

    virtual_ipaddress {

        172.17.111.111

    }

}

virtual_server 172.17.111.111 80 {

    delay_loop 6

    lb_algo wrr

    lb_kind DR

    nat_mask 255.255.255.255

    persistence_timeout 50

    protocol TCP


    real_server 172.17.111.222 80 {

        weight 1

        HTTP_GET {

            url {

              path /

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }

    }

    real_server 172.17.111.234 80 {

        weight 1

        HTTP_GET {

            url {

              path /

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }   

    }

}

vrrp_instance VI_2 {

    state BACKUP

    interface eth0

    virtual_router_id 51

#    nopreempt

    priority 90

    advert_int 1

 authentication {

        auth_type PASS

        auth_pass 1111

    }

    virtual_ipaddress {

        172.17.111.112

    }

}

 

virtual_server 172.17.111.112 443 {

    delay_loop 6

    lb_algo wrr

    lb_kind DR

    nat_mask 255.255.255.255

    persistence_timeout 50

    protocol TCP


    real_server 172.17.111.222 443 {

        weight 1

        HTTP_GET {

            url {

              path /

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }   

    }   

    real_server 172.17.111.234 443 {

        weight 1

        HTTP_GET {

            url {

              path /

            }

            connect_timeout 3

            nb_get_retry 3

            delay_before_retry 3

        }   

    }   

}

         ③开启转发功能

            echo 1 > /proc/sys/net/ipv4/ip_forward

         ④启动服务:

            systemctl start keepalived

 

3、Director-master2上操作:

         ①安装keepalived服务:

                yum install keepalived

         ②修改配置文件:

                vim /etc/keepalived/keepalived.conf

           内容与上面基本一致,只需修改vrrp_instance VI_1中

            state BACKUP

            priority 90  #小于100

          修改vrrp_instance VI_2中

            state MASTER

            priority 100

         

       ③开启转发功能

            echo 1 > /proc/sys/net/ipv4/ip_forward

         ④启动服务:

            systemctl start keepalived


4、两个后台服务器上操作:

          ①配置回环网卡:

ifconfig lo:0 172.17.111.111 broadcast 172.17.111.111 netmask 255.255.255.255 up

route add -host 172.17.111.111 lo:0

ifconfig lo:1 172.17.111.112 broadcast 172.17.111.111 netmask 255.255.255.255 up

route add -host 172.17.111.112 lo:1

          ②忽略ip与mac不匹配的问题:

            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


5、测试:刚启动服务时MASTER1主机上有172.17.111.111无172.17.111.112

              MASTER2主机上有172.17.111.112无172.17.111.111

实现基于keepalived高可用集群

实现基于keepalived高可用集群

当关闭MASTER2主机时,两个VIP都会在MASTER1主机上,而MASTER2主机上无VIP

实现基于keepalived高可用集群 

实现基于keepalived高可用集群


实验三、基于keepalived的使用NAT模型的主从模式集群


1、准备四台主机:一台master桥接与仅主机):DIP:192.168.199.145                                VIP1:172.17.111.10                                       VIP2:192.168.199.111(作为可漂移的DIP)

           一台backup桥接与仅主机):DIP:192.168.199.234                                      VIP1:172.17.111.10

                           VIP2:192.168.199.111(作为可漂移的DIP)

           一台后台服务器仅主机):RIP:192.168.199.146  可实现网站访问

           一台后台服务器仅主机):RIP:192.168.199.143  可实现网站访问

2、在master上操作:

            ①安装keepalived服务:

                  yum install keepalived

            ②修改配置文件(具体代码含义请参看实验一):


  vim /etc/keepalived/keepalived.conf

    ! Configuration File for keepalived

    global_defs {

       notification_email {

       root@localhost

       }

     notification_email_from Alexandre.Cassen@firewall.loc

     smtp_server 127.0.0.1

     smtp_connect_timeout 2

     router_id LVS_DEVEL2

     }

    vrrp_instance VI_1 {

        state MASTER

        interface eth0

        virtual_router_id 33

#        nopreempt

        priority 100

        advert_int 1

     authentication {

        auth_type PASS

        auth_pass 111111

     }

    virtual_ipaddress {

        172.17.111.10

        192.168.199.111

    }

}

 

    virtual_server 172.17.111.10 80 {

        delay_loop 6

        lb_algo wrr

        lb_kind NAT

        nat_mask 255.255.255.255

        persistence_timeout 50

           protocol TCP

 

    real_server 192.168.199.146 80 {

        weight 1

        HTTP_GET {

            url {

              path /

            }

           connect_timeout 3

           nb_get_retry 3

           delay_before_retry 3

        }

    }

    real_server 192.168.199.143 80 {

        weight 1

        HTTP_GET {

            url {

              path /

            }

           connect_timeout 3

           nb_get_retry 3

           delay_before_retry 3

        }   

    }

}

         ③开启转发功能

            echo 1 > /proc/sys/net/ipv4/ip_forward

         ④启动服务:

            systemctl start keepalived


 

3、backup上操作:

       ①安装keepalived服务:

                  yum install keepalived

       ②修改配置文件

   vim /etc/keepalived/keepalived.conf

     与上面配置一样,只需要修改state状态为BACKUP

       ③开启转发功能

            echo 1 > /proc/sys/net/ipv4/ip_forward

         ④启动服务:

            systemctl start keepalive

4、两台后台服务器上操作:添加网关,指向同一个VIP2

         route add default gw 192.168.199.111

5、测试:

      测试效果同实验一


感谢浏览,如有疑问,欢迎留言。

实现基于keepalived高可用集群