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    Linux利用keepalived实现lvs的高可用性方法

    栏目:Linux/apache问题 时间:2018-12-20 09:22

      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。这篇文章主要介绍了Linux利用keepalived实现lvs的高可用性 ,需要的朋友可以参考下
      lvs+keepalived是什么?
      keepalived工作原理
      keepalived是集群管理中保证集群高可用的一个服务软件,其功能类似于heartbeat,用来防止单点故障。 keepalived是以VRRP协议为实现基础的,VRRP全称Virtual Router Redundancy Protocol,即虚拟路由冗余协议。 虚拟路由冗余协议,可以认为是实现路由器高可用的协议,即将N台提供相同功能的路由器组成一个路由器组,这个组里面有一个master和多个backup,master上面有一个对外提供服务的vip(该路由器所在局域网内其他机器的默认路由为该vip),master会发组播,当backup收不到vrrp包时就认为master宕掉了,这时就需要根据VRRP的优先级来选举一个backup当master。这样的话就可以保证路由器的高可用了。
      LVS简介
      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。
      本文重点给大家介绍Linux利用keepalived实现lvs的高可用性的操作方法,感兴趣的朋友参考下吧。
      单主模型IPVS示例
      配置keepalive
      高可用的ipvs集群示例:修改keepalived配置文件
      修改主机: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 //接受邮件地址
      }
      notification_email_from keepalived@localhost //发送邮件地址
      smtp_server 127.0.0.1 //发送邮件服务器IP
      smtp_connect_timeout 30 //邮件连接超时时长
      router_id kptwo //路由id
      vrrp _mcast_group4 234.10.10.10 //指定vrrp协议的多播地址
      }
      vrrp_instance VI_1 { //vrrp协议的
      state MASTER //lvs的MASTER服务器
      interface ens37 //
      virtual_router_id 50 //虚拟路由
      priority 100 //权重为100.越大越先
      advert_int 1 //发送组博包的间隔
      authentication { //验证
      auth_type PASS //方式为pass( 明文)
      auth_pass 1111 //密码
      }
      virtual_ipaddress { //keepalived虚拟ip
      10.0.0.100/24
      }
      }
      virtual_server 10.0.0.100 80 {
      delay_loop 6 //检查后端服务器的时间间隔
      lb_algo wrr //定义调度方法
      lb_kind DR //集群的类型
      #persistence_timeout 50 //持久连接时长
      protocol TCP //服务协议,仅支持TCP
      real_server 192.168.234.47 80 { //后端real_server服务器地址
      weight 1 //权重
      HTTP_GET { //应用层检测
      url {
      path / //定义要监控的URL
      status_code 200 //判断上述检测机制为健康状态的响应码
      }
      connect_timeout 3 //连接请求的超时时长
      nb_get_retry 3 //重试次数
      delay_before_retry 3 //重试之前的延迟时长
      }
      }
      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
      }
      }
      }
      修改主机: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
      //暂无ipvsadm
      启动服务
      [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
      //启动服务lvs vs已配置好
      后端real_server准备
      增加ip在网卡上 修改限制arp通告及应答级别 rs1 rs2都做,网关并指向路由
      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
      安装httpd服务 写好网页文件
      启动服务
      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
      修改主机: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
      }
      }
      }
      修改主机: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
      }
      }
      }
      让10.0.0.100的ip优先分配至192.168.234.47 192.168.234.57备用
      让10.0.0.200的ip优先分配至192.168.234.57 192.168.234.47备用
      后端real_server准备
      修改192.168.234.57的vip为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
      现在宕掉一个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
      依然提供服务
      image6
      [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
      后一个实现基于前一个的基础上修改来的
      假设要实现sorry_server
      1.把rs服务都停掉。然后在lvs上安装apache或者nginx服务
      2.将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 //这一行来修改 写出服务出错之后的页面
      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
      }
      }
      }