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31-高可用集群KEEPALIVED

31-高可用集群KEEPALIVED

作者: Liang_JC | 来源:发表于2020-04-28 11:07 被阅读0次

    本章内容

    ◆ 高可用集群
    ◆ KeepAlived 组成
    ◆ keepAlived 配置

    集群Cluster

    • 集群类型：
      LB lvs/nginx（http/upstream, stream/upstream）
      HA 高可用性
      SPoF: Single Point of Failure
      HPC

    • 系统可用性的公式：A=MTBF/（MTBF+MTTR）
      (0,1), 95%
      几个9（指标）: 99%, ..., 99.999%，99.9999%

    • 系统故障：
      硬件故障：设计缺陷、 wear out（损耗）、自然灾害……
      软件故障：设计缺陷

    • 提升系统高用性的解决方案之降低MTTR
      手段：冗余redundant
      active/passive 主备
      active/active 双主
      active --> HEARTBEAT --> passive
      active <--> HEARTBEAT <--> active

    • 高可用的是“服务”
      HA nginx service：
      vip/nginx process[/shared storage]
      资源：组成一个高可用服务的“组件”
      (1) passive node的数量
      (2) 资源切换

    • shared storage：
      NAS：文件共享服务器；
      SAN：存储区域网络，块级别的共享

    • Network partition：网络分区
      ● quorum：法定人数
      with quorum： > total/2
      without quorum: <= total/2
      ● 隔离设备： fence
      node：STONITH = Shooting The Other Node In The Head
      断电重启
      资源：断开存储的连接

    • TWO nodes Cluster
      辅助设备：ping node, quorum disk

    • Failover：故障切换，即某资源的主节点故障时，将资源转移至其它节点的操作

    • Failback：故障移回，即某资源的主节点故障后重新修改上线后，将之前已转移至其它节点的资源重新切回的过程

    • HA Cluster实现方案:
      ● AIS：应用接口规范 完备复杂的HA集群
      RHCS：Red Hat Cluster Suite红帽集群套件
      heartbeat
      corosync
      ● vrrp协议实现：虚拟路由冗余协议
      keepalived

    KeepAlived

    • keepalived：
      vrrp协议：Virtual Router Redundancy Protocol

    • 术语：
      虚拟路由器：Virtual Router
      虚拟路由器标识：VRID(0-255)，唯一标识虚拟路由器
      物理路由器：
      master：主设备
      backup：备用设备
      priority：优先级
      VIP：Virtual IP
      VMAC：Virutal MAC (00-00-5e-00-01-VRID)

    • 通告：心跳，优先级等；周期性

    • 工作方式：抢占式，非抢占式

    • 安全工作：
      认证：
      无认证
      简单字符认证：预共享密钥
      MD5

    • 工作模式：
      主/备：单虚拟路径器
      主/主：主/备（虚拟路由器1），备/主（虚拟路由器2）

    • keepalived:
      vrrp协议的软件实现，原生设计目的为了高可用ipvs服务

    • 功能：
      ● vrrp协议完成地址流动
      ● 为vip地址所在的节点生成ipvs规则(在配置文件中预先定义)
      ● 为ipvs集群的各RS做健康状态检测
      ● 基于脚本调用接口通过执行脚本完成脚本中定义的功能，进而影响集群事务，以此支持nginx、 haproxy等服务

    • 组件：
      ● 核心组件：
      vrrp stack
      ipvs wrapper
      checkers
      ● 控制组件：配置文件分析器
      ● IO复用器
      ● 内存管理组件

    KeepAlived组成

    image.png

    KeepAlived实现

    • HA Cluster 配置准备：
      (1) 各节点时间必须同步
      ntp, chrony
      (2) 确保iptables及selinux不会成为阻碍
      (3) 各节点之间可通过主机名互相通信（对KA并非必须），建议使用/etc/hosts文件实现
      (4) 各节点之间的root用户可以基于密钥认证的ssh服务完成互相通信（对KA并非必须）

    • Keepalived安装：
      keepalived包，CentOS 6.4+ Base源

    • 程序环境：
      ● 主配置文件：/etc/keepalived/keepalived.conf
      ● 主程序文件：/usr/sbin/keepalived
      ● Unit File：/usr/lib/systemd/system/keepalived.service
      ● Unit File的环境配置文件：/etc/sysconfig/keepalived

    KeepAlived配置

    • 配置文件组件部分：

    • TOP HIERACHY
      ● GLOBAL CONFIGURATION
      Global definitions
      Static routes/addresses
      ● VRRPD CONFIGURATION
      VRRP synchronization group(s)：vrrp同步组
      VRRP instance(s)：即一个vrrp虚拟路由器
      ● LVS CONFIGURATION
      Virtual server group(s)
      Virtual server(s)：ipvs集群的vs和rs

    • 配置语法：

    • 配置虚拟路由器：
      vrrp_instance <STRING> {
      ....
      }

    • 专用参数：
      ● state MASTER|BACKUP：当前节点在此虚拟路由器上的初始状态；只能 有一个是MASTER，余下的都应该为BACKUP
      ● interface IFACE_NAME：绑定为当前虚拟路由器使用的物理接口
      ● virtual_router_id VRID：当前虚拟路由器惟一标识，范围是0-255
      ● priority 100：当前物理节点在此虚拟路由器中的优先级；范围1-254
      ● advert_int 1：vrrp通告的时间间隔，默认1s

    authentication { #认证机制
    auth_type AH|PASS
    auth_pass <PASSWORD> 仅前8位有效
}
virtual_ipaddress { #虚拟IP
    <IPADDR>/<MASK> brd <IPADDR> dev <STRING> scope <SCOPE> label <LABEL>
    192.168.200.17/24 dev eth1
    192.168.200.18/24 dev eth2 label eth2:1
}
track_interface { #配置监控网络接口，一旦出现故障，则转为FAULT状态   实现地址转移
    eth0
    eth1
    …
}
    • nopreempt：定义工作模式为非抢占模式
    • preempt_delay 300：抢占式模式，节点上线后触发新选举操作的延迟时长，默认模式
    • 定义通知脚本：
      notify_master <STRING>|<QUOTED-STRING>：
      当前节点成为主节点时触发的脚本
      notify_backup <STRING>|<QUOTED-STRING>：
      当前节点转为备节点时触发的脚本
      notify_fault <STRING>|<QUOTED-STRING>：
      当前节点转为“失败”状态时触发的脚本
      notify <STRING>|<QUOTED-STRING>：
      通用格式的通知触发机制，一个脚本可完成以上三种状态的转换时的通知

    小笔记：搭建keepalived

    #环境：6台机器，Client:172.16.0.6  Router:172.16.0.7、192.168.37.7  RS1:192.168.37.17   RS2:192.168.37.27   ka1:192.168.37.37、192.168.37.100 ka2:192.168.37.47、192.168.37.100
#router2块网卡，桥接与nat模式

#ka1
yum install keepalived
cd /etc/keepalived
cp keepalived.conf{,.bak}
ssh-keygen
ssh-copy-id 192.168.37.47
echo "192.168.37.37 ka1" >> /etc/hosts
echo "192.168.37.47 ka2" >> /etc/hosts
vim keepalived.conf
! Configuration File for keepalived
global_defs {
    notification_email {
        root@localhost                  #发给本机root邮件
    }
    notification_email_from keepalived@localhost    #以什么身份发邮件
    smtp_server 127.0.0.1               #发邮件的地址
    smtp_connect_timeout 30
    router_id ka1                       #主机名
    vrrp_mcast_group4 224.100.100.100       #D类地址，多播
}

vrrp_instance VI_1 {            #虚拟路由器
    state MASTER                #在另一个结点上为BACKUP
    interface eth0              #网卡接口
    virtual_router_id 66        #多个节点必须相同
    priority 100                #优先级，在另一个结点上要小于这个值
    advert_int 1                #通告间隔1s
    authentication {
        auth_type PASS           #预共享密钥认证
        auth_pass 123456        #密码
    }
    virtual_ipaddress {
        192.168.37.100/24 dev eth0 label eth0:1
    }
}
systemctl start keepalived

#ka2
yum install keepalived
cd /etc/keepalived
cp keepalived.conf{,.bak}
ssh-keygen
ssh-copy-id 192.168.37.37
echo "192.168.37.37 ka1" >> /etc/hosts
echo "192.168.37.47 ka2" >> /etc/hosts
vim keepalived.conf
! Configuration File for keepalived
global_defs {
    notification_email {
        root@localhost                  #发给本机root邮件
    }
    notification_email_from keepalived@localhost    #以什么身份发邮件
    smtp_server 127.0.0.1               #发邮件的地址
    smtp_connect_timeout 30
    router_id ka2                       #主机名
    vrrp_mcast_group4 224.100.100.100       #D类地址，多播
}

vrrp_instance VI_1 {            #虚拟路由器
    state BACKUP                
    interface eth0              #网卡接口
    virtual_router_id 66        #多个节点必须相同
    priority 80                 #优先级
    advert_int 1                #通告间隔1s
    authentication {
        auth_type PASS           #预共享密钥认证
        auth_pass 123456        #密码
    }
    virtual_ipaddress {
        192.168.37.100/24 dev eth0 label eth0:1
    }
}
systemctl start keepalived

#RS1、RS2
yum install httpd -y
echo `hostname` > /var/www/html/index.html
systemctl start httpd
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
ip address add 192.168.37.100/32 dev lo label lo:1

#抓包查看
tcpdump -i eth0 -nn host 224.100.100.100

    KeepAlived单主配置示例

    单主配置示例：

    ! 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 node1 #主机名，在另一结点为node2
    vrrp_mcast_group4 224.0.100.100
}

vrrp_instance VI_1 {
    state MASTER #在另一个结点上为BACKUP
    interface eth0
    virtual_router_id 6 #多个节点必须相同
    priority 100 #在另一个结点上为90
    advert_int 1 #通告间隔1s
    authentication {
        auth_type PASS #预共享密钥认证
        auth_pass 571f97b2
    }
    virtual_ipaddress {
        172.18.100.66/16 dev eth0 label eth0:0
    }
    track_interface {
        eth0
    }
}

    KeepAlived双主配置

    • 脚本的调用方法：

    • 在vrrp_instance VI_1 语句块最后面加下面行
      notify_master "/etc/keepalived/notify.sh master"
      notify_backup "/etc/keepalived/notify.sh backup"
      notify_fault "/etc/keepalived/notify.sh fault"

    示例通知脚本

    #!/bin/bash

contact='root@localhost'
notify() {
    mailsubject="$(hostname) to be $1, vip floating"
    mailbody="$(date +'%F %T'): vrrp transition, $(hostname) changed to be $1"
    echo "$mailbody" | mail -s "$mailsubject" $contact
}
case $1 in
master)
    notify master
    ;;
backup)
    notify backup
    ;;
fault)
    notify fault
    ;;
*)
    echo "Usage: $(basename $0) {master|backup|fault}"
    exit 1
    ;;
esac

    邮件设置

    KeepAlived双主配置

    #双主模型示例：
! 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 node1
    vrrp_mcast_group4 224.0.100.100
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 6
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 571f97b2
    }
    virtual_ipaddress {
            172.16.0.10/16 dev eth0
    }
}

vrrp_instance VI_2 {
    state BACKUP
    interface eth0
    virtual_router_id 8
    priority 98
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 578f07b2
    }
    virtual_ipaddress {
        172.16.0.11/16 dev eth0
    }
}

    小笔记：双主配置

    #ka1
vim /etc/keepalived/notify.sh
#!/bin/bash

contact='root@localhost'
notify() {
    mailsubject="$(hostname) to be $1, vip floating"
    mailbody="$(date +'%F %T'): vrrp transition, $(hostname) changed to be $1"
    echo "$mailbody" | mail -s "$mailsubject" $contact
}
case $1 in
master)
    notify master
    ;;
backup)
    notify backup
    ;;
fault)
    notify fault
    ;;
*)
    echo "Usage: $(basename $0) {master|backup|fault}"
    exit 1
    ;;
esac

vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    notification_email {
        root@localhost                  #发给本机root邮件
    }
    notification_email_from keepalived@localhost    #以什么身份发邮件
    smtp_server 127.0.0.1               #发邮件的地址
    smtp_connect_timeout 30
    router_id ka1                       #主机名
    vrrp_mcast_group4 224.100.100.100       #D类地址，多播
}

vrrp_instance VI_1 {            #虚拟路由器
    state MASTER                #在另一个结点上为BACKUP
    interface eth0              #网卡接口
    virtual_router_id 66        #多个节点必须相同
    priority 100                #优先级，在另一个结点上要小于这个值
    advert_int 1                #通告间隔1s
    authentication {
        auth_type PASS           #预共享密钥认证
        auth_pass 123456        #密码
    }
    virtual_ipaddress {
        192.168.37.100/24 dev eth0 label eth0:1
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"  
}
chmod +x /etc/keepalived/notify.sh
systemctl restart keepalived

#ka2
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    notification_email {
        root@localhost                  #发给本机root邮件
    }
    notification_email_from keepalived@localhost    #以什么身份发邮件
    smtp_server 127.0.0.1               #发邮件的地址
    smtp_connect_timeout 30
    router_id ka2                       #主机名
    vrrp_mcast_group4 224.100.100.100       #D类地址，多播
}

vrrp_instance VI_1 {            #虚拟路由器
    state BACKUP                
    interface eth0              #网卡接口
    virtual_router_id 66        #多个节点必须相同
    priority 80                 #优先级
    advert_int 1                #通告间隔1s
    authentication {
        auth_type PASS           #预共享密钥认证
        auth_pass 123456        #密码
    }
    virtual_ipaddress {
        192.168.37.100/24 dev eth0 label eth0:1
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"  
}
chmod +x /etc/keepalived/notify.sh
systemctl restart keepalived

    小笔记：keepalived日志

    vim /etc/sysconfig/keepalived
    KEEPALIVED_OPTIONS="-D -S 6"
vim /etc/rsyslog.conf
    local6.*    /var/log/keepalived.log
systemctl restart rsyslog keepalived

    小笔记：设置e-mail

    vim ~/.mailrc
    set from=184116857@qq.com
    set smtp=smtp.qq.com
    set smtp-auth-user=184116857@qq.com
    set smtp-auth-password=lzhdjmtznbftbiai
    set smtp-auth=login
    set ssl-verify=ignore
echo test | mail -s linux 184116857@qq.com

    小笔记：keepalived 双主双从

    #ka1
vim /etc/keepalived/keepalived.conf
vrrp_instance VI_2 {            #虚拟路由器
    state BACKUP                #在另一个结点上为BACKUP
    interface eth0              #网卡接口
    virtual_router_id 88        #多个节点必须相同
    priority 80                 #优先级，在另一个结点上要小于这个值
    advert_int 1                #通告间隔1s
    authentication {
        auth_type PASS           #预共享密钥认证
        auth_pass 654321        #密码
    }
    virtual_ipaddress {
        192.168.37.200/24 dev eth0 label eth0:2
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"  
}
systemctl restart keepalived

#ka2
vim /etc/keepalived/keepalived.conf
vrrp_instance VI_2 {            #虚拟路由器
    state MASTER                
    interface eth0              #网卡接口
    virtual_router_id 88        #多个节点必须相同
    priority 100                #优先级
    advert_int 1                #通告间隔1s
    authentication {
        auth_type PASS           #预共享密钥认证
        auth_pass 654321        #密码
    }
    virtual_ipaddress {
        192.168.37.200/24 dev eth0 label eth0:2
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"  
}
systemctl restart keepalived

#抓包查看
tcpdump -i eth0 -nn

    KeepAlived支持IPVS

    虚拟服务器：
    配置参数：

    virtual_server IP port | virtual_server fwmark int
{
    ...
    real_server {
    ...
    }
    ...
}

    常用参数

    • delay_loop <INT>：检查后端服务器的时间间隔

    • lb_algo rr|wrr|lc|wlc|lblc|sh|dh：定义调度方法

    • lb_kind NAT|DR|TUN：集群的类型

    • persistence_timeout <INT>：持久连接时长

    • protocol TCP：服务协议，仅支持TCP

    • sorry_server <IPADDR> <PORT>：所有RS故障时，备用服务器地址

    • real_server <IPADDR> <PORT>

    {
    weight <INT> RS权重
    notify_up <STRING>|<QUOTED-STRING> RS上线通知脚本
    notify_down <STRING>|<QUOTED-STRING> RS下线通知脚本
    HTTP_GET|SSL_GET|TCP_CHECK|SMTP_CHECK|MISC_CHEC K { ... }：定义当前主机的健康状态检测方法
}

    KeepAlived配置检测

    HTTP_GET|SSL_GET：应用层检测

    HTTP_GET|SSL_GET {
url {
    path <URL_PATH>：定义要监控的URL
    status_code <INT>：判断上述检测机制为健康状态的响应码
    digest <STRING>：判断为健康状态的响应的内容的校验码
}
    connect_timeout <INTEGER>：连接请求的超时时长
    nb_get_retry <INT>：重试次数
    delay_before_retry <INT>：重试之前的延迟时长
    connect_ip <IP ADDRESS>：向当前RS哪个IP地址发起健康状态检测请求
    connect_port <PORT>：向当前RS的哪个PORT发起健康状态检测请求
    bindto <IP ADDRESS>：发出健康状态检测请求时使用的源地址
    bind_port <PORT>：发出健康状态检测请求时使用的源端口
} 

传输层检测 TCP_CHECK
TCP_CHECK {
    connect_ip <IP ADDRESS>：向当前RS的哪个IP地址发起健康状态检测请求
    connect_port <PORT>：向当前RS的哪个PORT发起健康状态检测请求
    bindto <IP ADDRESS>：发出健康状态检测请求时使用的源地址
    bind_port <PORT>：发出健康状态检测请求时使用的源端口
    connect_timeout <INTEGER>：连接请求的超时时长
}

    单主模型IPVS示例

    #高可用的ipvs集群示例：
! 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 node1
    vrrp_mcast_group4 224.0.100.10
}
    
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 6
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 571f97b2
    }
    virtual_ipaddress {
        172.16.0.10/16 dev eth0
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

virtual_server 172.16.0.10 80 {
    delay_loop 3
    lb_algo rr
    lb_kind DR
    protocol TCP
    sorry_server 127.0.0.1 80
    real_server 172.16.0.11 80 {
        weight 1
        HTTP_GET {
            url {
                path /
                status_code 200
            }
        connect_timeout 1
        nb_get_retry 3
        delay_before_retry 1
        }
    }
}

real_server 172.16.0.12 80 {
    weight 1
    HTTP_GET {
        url {   
            path /
            status_code 200
        }
        connect_timeout 1
        nb_get_retry 3
        delay_before_retry 1
    }
}

    小笔记：配置单主IPVS

    #ka1、ka2
vim /etc/keepalived/keepalived.conf     #把vrrp_instance VI_2的内容全部删除，追加以下
virtual_server 192.168.37.100 80 {      #LVS调度器
    delay_loop 6                #检查后端服务器的时间间隔
    lb_algo rr                  #调度方法rr|wrr|sh|dh|lc|wlc|sed|nq|lblc|lblcr
    lb_kind DR                  #集群的类型NAT|DR|TUN
    #persistence_timeout 50     #持久连接
    protocol TCP
    sorry_server 127.0.0.1 80
    
    real_server 192.168.37.17 80 {
        weight 1
        HTTP_GET {
            url {
                path /          #定义要监控的URL
                status_code 200 #定义健康状态码
            }
        connect_timeout 1       #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 192.168.37.27 80 {
        weight 1
        HTTP_GET {
            url {
                path /
                status_code 200
            }
        connect_timeout 1
        nb_get_retry 3
        delay_before_retry 3
        }
    }
    
}
systemctl restart keepalived

#RS1、RS2
yum install httpd -y
echo `hostname` > /var/www/html/index.html
systemctl start httpd
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
ip address add 192.168.37.100/32 dev lo label lo:1

#client
while true;do curl 192.168.37.100;sleep 0.5;done

    双主模式的lvs集群示例

    #双主模式的lvs集群，拓扑、实现过程；
#配置示例（一个节点）：
! Configuration File for keepalived
global_defs {
    notification_email {
        root@localhost
    }
    notification_email_from kaadmin@localhost
    smtp_server 127.0.0.1
    smtp_connect_timeout 30
    router_id node1
    vrrp_mcast_group4 224.0.100.100
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 6
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass f1bf7fde
    }
    virtual_ipaddress {
        172.16.0.80/16 dev eth0 label eth0:0
    }
    track_interface {
        eth0
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}
vrrp_instance VI_2 {
    state BACKUP
    interface eth0
    virtual_router_id 8
    priority 98
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass f2bf7ade
    }
    virtual_ipaddress {
        172.16.0.90/16 dev eth0 label eth0:1
    }
    track_interface {
        eth0
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}
virtual_server fwmark 3 {
    delay_loop 2
    lb_algo rr
    lb_kind DR
    nat_mask 255.255.0.0
    protocol TCP
    sorry_server 127.0.0.1 80
    
    real_server 172.16.0.11 80 {
        weight 1
        HTTP_GET {
        url {
            path /
            status_code 200
            }
        connect_timeout 2
        nb_get_retry 3
        delay_before_retry 3
        }
    }

    real_server 172.16.0.12 80 {
        weight 1
        HTTP_GET {
        url {
            path /
            status_code 200
        }
        connect_timeout 2
        nb_get_retry 3
        delay_before_retry 3
        }
    }
}

    小笔记：双主配置

    #ka1
global_defs {
   notification_email {
     root@localhost
   }
   notification_email_from keepalived@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id ka1
   vrrp_mcast_group4 224.0.0.100
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 10
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.37.100/24 dev eth0 label eth0:1
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

vrrp_instance VI_2 {
    state BACKUP
    interface eth0
    virtual_router_id 20
    priority 60
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 654321
    }
    virtual_ipaddress {
        192.168.37.100/24 dev eth0 label eth0:2
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}
virtual_server 192.168.37.100 80 {
    delay_loop 5
    lb_algo rr
    lb_kind DR
    !persistence_timeout 50
    protocol TCP

    sorry_server 127.0.0.1 80

    real_server 192.168.37.17 80 {
        weight 1
        HTTP_GET {
            url {
              path /
          status_code 200
            }
            connect_timeout 1
            nb_get_retry 3
            delay_before_retry 3
        }
    }
    
    real_server 192.168.37.27 80 {
        weight 1
        HTTP_GET {
            url {
              path /
          status_code 200
            }
            connect_timeout 1
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}
systemctl restart keepalived.service

#ka2
global_defs {
   notification_email {
     root@localhost
   }
   notification_email_from keepalived@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id ka1
   vrrp_mcast_group4 224.0.0.100
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 10
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.37.100/24 dev eth0 label eth0:1
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

vrrp_instance VI_2 {
    state MASTER
    interface eth0
    virtual_router_id 20
    priority 70
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 654321
    }
    virtual_ipaddress {
        192.168.37.100/24 dev eth0 label eth0:2
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}
virtual_server 192.168.37.100 80 {
    delay_loop 5
    lb_algo rr
    lb_kind DR
    !persistence_timeout 50
    protocol TCP

    sorry_server 127.0.0.1 80

    real_server 192.168.37.17 80 {
        weight 1
        HTTP_GET {
            url {
              path /
          status_code 200
            }
            connect_timeout 1
            nb_get_retry 3
            delay_before_retry 3
        }
    }
    
    real_server 192.168.37.27 80 {
        weight 1
        HTTP_GET {
            url {
              path /
          status_code 200
            }
            connect_timeout 1
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}
systemctl restart keepalived.service

#client
while true;do curl 192.168.37.100;sleep 0.5;done

    keepalived调用脚本进行资源监控

    • keepalived调用外部的辅助脚本进行资源监控，并根据监控的结果状态能实现优先动态调整
    • vrrp_script:自定义资源监控脚本，vrrp实例根据脚本返回值，公共定义，可被多个实例调用，
      定义在vrrp实例之外
    • track_script:调用vrrp_script定义的脚本去监控资源，定义在实例之内，调用事先定义的
      vrrp_script
    • 分两步：(1) 先定义一个脚本；(2) 调用此脚本
    vrrp_script <SCRIPT_NAME> {
    script ""
    interval INT
    weight -INT
}
track_script {
    SCRIPT_NAME_1
    SCRIPT_NAME_2
}

    示例：高可用nginx服务

    ! 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 node1
    vrrp_mcast_group4 224.0.100.100
}
vrrp_script chk_down {
    script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
    interval 1
    weight -20
}
vrrp_script chk_nginx {
    script “/usr/bin/killall -0 nginx "
    interval 1
    weight -20
    fall 2 #2次检测失败为失败
    rise 1 #1次检测成功为成功
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 14
    priority 100
    advert_int 1    
    authentication {
        auth_type PASS
        auth_pass 571f97b2
    }
    virtual_ipaddress {
        172.18.0.93/16 dev eth0
    }
    track_script {
        chk_down
        chk_nginx
    }
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

    同步组

    LVS NAT模型VIP和DIP需要同步，需要同步组

    vrrp_sync_group VG_1 {
    group {
        VI_1 # name of vrrp_instance (below)
        VI_2 # One for each moveable IP
    }
}
vrrp_instance VI_1 {
    eth0
    vip
}
vrrp_instance VI_2 {
    eth1
    dip
}

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