Linux利用keepalived實(shí)現(xiàn)lvs的高可用性的操作方法

更新時(shí)間：2018年09月02日 17:02:53 作者：OrochWang

LVS是Linux Virtual Server的簡(jiǎn)寫(xiě)，意即Linux虛擬服務(wù)器，是一個(gè)虛擬的服務(wù)器集群系統(tǒng)。這篇文章主要介紹了Linux利用keepalived實(shí)現(xiàn)lvs的高可用性 ,需要的朋友可以參考下

lvs+keepalived是什么？

keepalived工作原理

keepalived是集群管理中保證集群高可用的一個(gè)服務(wù)軟件，其功能類似于heartbeat，用來(lái)防止單點(diǎn)故障。 keepalived是以VRRP協(xié)議為實(shí)現(xiàn)基礎(chǔ)的，VRRP全稱Virtual Router Redundancy Protocol，即虛擬路由冗余協(xié)議。虛擬路由冗余協(xié)議，可以認(rèn)為是實(shí)現(xiàn)路由器高可用的協(xié)議，即將N臺(tái)提供相同功能的路由器組成一個(gè)路由器組，這個(gè)組里面有一個(gè)master和多個(gè)backup，master上面有一個(gè)對(duì)外提供服務(wù)的vip（該路由器所在局域網(wǎng)內(nèi)其他機(jī)器的默認(rèn)路由為該vip），master會(huì)發(fā)組播，當(dāng)backup收不到vrrp包時(shí)就認(rèn)為master宕掉了，這時(shí)就需要根據(jù)VRRP的優(yōu)先級(jí)來(lái)選舉一個(gè)backup當(dāng)master。這樣的話就可以保證路由器的高可用了。

LVS簡(jiǎn)介

LVS是Linux Virtual Server的簡(jiǎn)寫(xiě)，意即Linux虛擬服務(wù)器，是一個(gè)虛擬的服務(wù)器集群系統(tǒng)。本項(xiàng)目在1998年5月由章文嵩博士成立，是中國(guó)國(guó)內(nèi)最早出現(xiàn)的自由軟件項(xiàng)目之一。目前有三種IP負(fù)載均衡技術(shù)（VS/NAT、VS/TUN和VS/DR），十種調(diào)度算法。

本文重點(diǎn)給大家介紹Linux利用keepalived實(shí)現(xiàn)lvs的高可用性的操作方法，感興趣的朋友參考下吧。

單主模型IPVS示例

配置keepalive

高可用的ipvs集群示例：修改keepalived配置文件

修改主機(jī)：192.168.234.27的keepalived配置文件

[root@234c27 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost //接受郵件地址
}
notification_email_from keepalived@localhost //發(fā)送郵件地址
smtp_server 127.0.0.1 //發(fā)送郵件服務(wù)器IP
smtp_connect_timeout 30 //郵件連接超時(shí)時(shí)長(zhǎng)
router_id kptwo //路由id
vrrp _mcast_group4 234.10.10.10 //指定vrrp協(xié)議的多播地址
}
vrrp_instance VI_1 { //vrrp協(xié)議的
state MASTER //lvs的MASTER服務(wù)器
interface ens37 //
virtual_router_id 50 //虛擬路由
priority 100 //權(quán)重為100.越大越先
advert_int 1 //發(fā)送組博包的間隔
authentication { //驗(yàn)證
auth_type PASS //方式為pass( 明文)
auth_pass 1111 //密碼
}
virtual_ipaddress { //keepalived虛擬ip
10.0.0.100/24
}
}
virtual_server 10.0.0.100 80 {
 delay_loop 6 //檢查后端服務(wù)器的時(shí)間間隔
 lb_algo wrr //定義調(diào)度方法
 lb_kind DR //集群的類型
 #persistence_timeout 50 //持久連接時(shí)長(zhǎng)
 protocol TCP //服務(wù)協(xié)議，僅支持TCP
 real_server 192.168.234.47 80 { //后端real_server服務(wù)器地址
  weight 1 //權(quán)重
  HTTP_GET { //應(yīng)用層檢測(cè)
   url {
    path / //定義要監(jiān)控的URL
    status_code 200 //判斷上述檢測(cè)機(jī)制為健康狀態(tài)的響應(yīng)碼
   }
   connect_timeout 3 //連接請(qǐng)求的超時(shí)時(shí)長(zhǎng)
   nb_get_retry 3 //重試次數(shù)
   delay_before_retry 3 //重試之前的延遲時(shí)長(zhǎng)
  }
 }
 real_server 192.168.234.57 80 {
  weight 2
  HTTP_GET {
   url {
    path /
    status_code 200
   }
   connect_timeout 3
   nb_get_retry 3
   delay_before_retry 3
  }
 }
}

修改主機(jī)：192.168.234.37的keepalived配置文件

[root@234c37 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
 notification_email {
  root@localhost
 }
 notification_email_from keepalived@localhost
 smtp_server 127.0.0.1
 smtp_connect_timeout 30
 router_id kptwo
 vrrp _mcast_group4 234.10.10.10
}
vrrp_instance VI_1 {
 state BACKUP
 interface ens37
 virtual_router_id 50
 priority 80
 advert_int 1
 authentication {
  auth_type PASS
  auth_pass 1111
 }
 virtual_ipaddress {
  10.0.0.100/24
 }
}
virtual_server 10.0.0.100 80 {
 delay_loop 6
 lb_algo wrr
 lb_kind DR
 #persistence_timeout 50
 protocol TCP
 sorry_server 127.0.0.1:80
 real_server 192.168.234.47 80 {
  weight 1
  HTTP_GET {
   url {
    path /
    status_code 200
   }
   connect_timeout 3
   nb_get_retry 3
   delay_before_retry 3
  }
 }
 real_server 192.168.234.57 80 {
  weight 2
  HTTP_GET {
   url {
    path /
    status_code 200
   }
   connect_timeout 3
   nb_get_retry 3
   delay_before_retry 3
  }
 }
}

查看keepalived

[root@234c37 ~]# systemctl status keepalived
● keepalived.service - LVS and VRRP High Availability Monitor
 Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
 Active: inactive (dead)
…………
[root@234c37 ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
 -> RemoteAddress:Port   Forward Weight ActiveConn InActConn
//暫無(wú)ipvsadm

啟動(dòng)服務(wù)

[root@234c27 keepalived]# systemctl start keepalived.service
[root@234c27 keepalived]# systemctl status keepalived.service
● keepalived.service - LVS and VRRP High Availability Monitor
 Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
 Active: active (running) since Fri 2018-08-31 20:30:02 CST; 12s ago
 Process: 9657 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)
 Main PID: 9658 (keepalived)
………………
[root@234c27 keepalived]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
 -> RemoteAddress:Port   Forward Weight ActiveConn InActConn
TCP 10.0.0.100:80 wrr
 -> 192.168.234.47:80   Route 1  0   0
 -> 192.168.234.57:80   Route 2  0   0
//啟動(dòng)服務(wù)lvs vs已配置好

后端real_server準(zhǔn)備

增加ip在網(wǎng)卡上修改限制arp通告及應(yīng)答級(jí)別 rs1 rs2都做，網(wǎng)關(guān)并指向路由

ip a a 10.0.0.100/32 dev ens37
echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce
route add default gw 192.168.234.17

安裝httpd服務(wù) 寫(xiě)好網(wǎng)頁(yè)文件

啟動(dòng)服務(wù)

image

多主模型IPVS示例

配置keepalive

高可用的ipvs集群示例：修改keepalived配置文件

修改主機(jī)：192.168.234.27的keepalived配置文件

[root@234c27 keepalived]# vim /etc/keepalived/keepalived.conf
global_defs {
  notification_email {
   root@localhost
  }
  notification_email_from keepalived@localhost
  smtp_server 127.0.0.1
  smtp_connect_timeout 30
  router_id kpone
  vrrp _mcast_group4 234.10.10.10
}
vrrp_instance VI_1 {
  state MASTER
  interface ens37
  virtual_router_id 50
  priority 100
  advert_int 1
  authentication {
    auth_type PASS
    auth_pass 1111
  }
  virtual_ipaddress {
    10.0.0.100/24
  }
}
vrrp_instance VI_2 {
  state BACKUP
  interface ens37
  virtual_router_id 51
  priority 80
  advert_int 1
  authentication {
    auth_type PASS
    auth_pass 2222
  }
  virtual_ipaddress {
    10.0.0.200/24
  }
}
virtual_server 10.0.0.100 80 {
  delay_loop 6
  lb_algo wrr
  lb_kind DR
  #persistence_timeout 50
  protocol TCP
  #sorry_server 127.0.0.1:80
  real_server 192.168.234.47 80 {
    weight 1
    HTTP_GET {
      url {
       path /
       status_code 200
      }
      connect_timeout 3
      nb_get_retry 3
      delay_before_retry 3
    }
  }
}
virtual_server 10.0.0.200 80 {
  delay_loop 6
  lb_algo wrr
  lb_kind DR
  #persistence_timeout 50
  protocol TCP
  #sorry_server 127.0.0.1:80
  real_server 192.168.234.57 80 {
    weight 1
    HTTP_GET {
      url {
       path /
       status_code 200
      }
      connect_timeout 3
      nb_get_retry 3
      delay_before_retry 3
    }
  }
}

修改主機(jī)：192.168.234.37的keepalived配置文件

[root@234c37 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
  notification_email {
   root@localhost
  }
  notification_email_from keepalived@localhost
  smtp_server 127.0.0.1
  smtp_connect_timeout 30
  router_id kptwo
  vrrp _mcast_group4 234.10.10.10
}
vrrp_instance VI_1 {
  state BACKUP
  interface ens37
  virtual_router_id 50
  priority 80
  advert_int 1
  authentication {
    auth_type PASS
    auth_pass 1111
  }
  virtual_ipaddress {
    10.0.0.100/24
  }
}
vrrp_instance VI_2 {
  state MASTER
  interface ens37
  virtual_router_id 51
  priority 100
  advert_int 1
  authentication {
    auth_type PASS
    auth_pass 2222
  }
  virtual_ipaddress {
    10.0.0.200/24
  }
}
virtual_server 10.0.0.100 80 {
  delay_loop 6
  lb_algo wrr
  lb_kind DR
  #persistence_timeout 50
  protocol TCP
  #sorry_server 127.0.0.1:80
  real_server 192.168.234.47 80 {
    weight 1
    HTTP_GET {
      url {
       path /
       status_code 200
      }
      connect_timeout 3
      nb_get_retry 3
      delay_before_retry 3
    }
  }
}
virtual_server 10.0.0.200 80 {
  delay_loop 6
  lb_algo wrr
  lb_kind DR
  #persistence_timeout 50
  protocol TCP
  #sorry_server 127.0.0.1:80
  real_server 192.168.234.57 80 {
    weight 1
    HTTP_GET {
      url {
       path /
       status_code 200
      }
      connect_timeout 3
      nb_get_retry 3
      delay_before_retry 3
    }
  }
}

讓10.0.0.100的ip優(yōu)先分配至192.168.234.47 192.168.234.57備用

讓10.0.0.200的ip優(yōu)先分配至192.168.234.57 192.168.234.47備用

后端real_server準(zhǔn)備

修改192.168.234.57的vip為10.0.0.200/32

  [root@234c27 keepalived]# ipvsadm -Ln
  IP Virtual Server version 1.2.1 (size=4096)
  Prot LocalAddress:Port Scheduler Flags
   -> RemoteAddress:Port      Forward Weight ActiveConn InActConn
  TCP 10.0.0.100:80 wrr
   -> 192.168.234.47:80      Route  1   0     0
  TCP 10.0.0.200:80 wrr
  -> 192.168.234.57:80      Route  1   0     0

現(xiàn)在宕掉一個(gè)lvs

  [root@234c27 keepalived]# systemctl stop keepalived.service
  [root@234c27 keepalived]# ipvsadm -Ln
  IP Virtual Server version 1.2.1 (size=4096)
  Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port      Forward Weight ActiveConn InActConn

依然提供服務(wù)

 [root@234c37 ~]# ipvsadm -Ln
 IP Virtual Server version 1.2.1 (size=4096)
  Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port      Forward Weight ActiveConn InActConn
  TCP 10.0.0.100:80 wrr
   -> 192.168.234.47:80      Route  1   0     21
  TCP 10.0.0.200:80 wrr
   -> 192.168.234.57:80      Route  1   0     39

后一個(gè)實(shí)現(xiàn)基于前一個(gè)的基礎(chǔ)上修改來(lái)的

假設(shè)要實(shí)現(xiàn)sorry_server

1.把rs服務(wù)都停掉。然后在lvs上安裝apache或者nginx服務(wù)

2.將keepalived配置文件中的

virtual_server 10.0.0.200 80 {
  delay_loop 6
  lb_algo wrr
  lb_kind DR
  #persistence_timeout 50
  protocol TCP
  #sorry_server 127.0.0.1:80 //這一行來(lái)修改 寫(xiě)出服務(wù)出錯(cuò)之后的頁(yè)面
  real_server 192.168.234.57 80 {
    weight 1
    HTTP_GET {
      url {
       path /
       status_code 200
      }
      connect_timeout 3
      nb_get_retry 3
      delay_before_retry 3
    }
  }
}

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