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所属分类：linux技术
keepalived高可用
目录
keepalived简介
keepalived官网
Keepalived 软件起初是专为LVS负载均衡软件设计的，用来管理并监控LVS集群系统中各个服务节点的状态，后来又加入了可以实现高可用的VRRP功能。因此，Keepalived除了能够管理LVS软件外，还可以作为其他服务（例如：Nginx、Haproxy、MySQL等）的高可用解决方案软件。
Keepalived软件主要是通过VRRP协议实现高可用功能的。VRRP是Virtual Router RedundancyProtocol(虚拟路由器冗余协议）的缩写，VRRP出现的目的就是为了解决静态路由单点故障问题的，它能够保证当个别节点宕机时，整个网络可以不间断地运行。
所以，Keepalived 一方面具有配置管理LVS的功能，同时还具有对LVS下面节点进行健康检查的功能，另一方面也可实现系统网络服务的高可用功能。
keepalived的重要功能
eepalived 有三个重要的功能，分别是：
管理LVS负载均衡软件
实现LVS集群节点的健康检查
作为系统网络服务的高可用性（failover）
keepalived工作原理描述
Keepalived高可用对之间是通过VRRP通信的，因此，我们从 VRRP开始了解起：
- VRRP,全称 Virtual Router Redundancy Protocol,中文名为虚拟路由冗余协议，VRRP的出现是为了解决静态路由的单点故障。
- VRRP是通过一种竟选协议机制来将路由任务交给某台 VRRP路由器的。
- VRRP用 IP多播的方式（默认多播地址（224.0_0.18))实现高可用对之间通信。
- 工作时主节点发包，备节点接包，当备节点接收不到主节点发的数据包的时候，就启动接管程序接管主节点的开源。备节点可以有多个，通过优先级竞选，但一般 Keepalived系统运维工作中都是一对。
- VRRP使用了加密协议加密数据，但Keepalived官方目前还是推荐用明文的方式配置认证类型和密码。
介绍完 VRRP,接下来我再介绍一下 Keepalived服务的工作原理：
Keepalived高可用是通过 VRRP 进行通信的， VRRP是通过竞选机制来确定主备的，主的优先级高于备，因此，工作时主会优先获得所有的资源，备节点处于等待状态，当主挂了的时候，备节点就会接管主节点的资源，然后顶替主节点对外提供服务。
在 Keepalived 服务之间，只有作为主的服务器会一直发送 VRRP 广播包,告诉备它还活着，此时备不会枪占主，当主不可用时，即备监听不到主发送的广播包时，就会启动相关服务接管资源，保证业务的连续性.接管速度最快可以小于1秒。
keepalived实现nginx负载均衡机高可用
环境说明:
| 系统信息 | 主机名 | IP |
|---|---|---|
| centos 8.5 | master | 192.168.222.138 |
| centos 8.5 | backup | 192.168.222.139 |
本次高可用虚拟IP（VIP）地址暂定为192.168.222.133
keepalived安装
阿里云官网
配置主keepalived
关闭防火墙: [root@master ~]# systemctl stop firewalld.service [root@master ~]# vim /etc/selinux/config SELINUX=disabled [root@master ~]# setenforce 0 [root@master ~]# systemctl disable --now firewalld.service Removed /etc/systemd/system/multi-user.target.wants/firewalld.service. Removed /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service. 配置网络源: [root@master ~]# dnf -y install wget [root@master ~]# cd /etc/yum.repos.d/ [root@master yum.repos.d]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo [root@master yum.repos.d]#sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo 安装epel源: [root@master yum.repos.d]#dnf install -y https://mirrors.aliyun.com/epel/epel-release-latest-8.noarch.rpm [root@master yum.repos.d]#sed -i 's|^#baseurl=https://download.example/pub|baseurl=https://mirrors.aliyun.com|' /etc/yum.repos.d/epel* [root@master yum.repos.d]#sed -i 's|^metalink|#metalink|' /etc/yum.repos.d/epel* [root@master yum.repos.d]# ls CentOS-Base.repo epel-next-testing.repo epel-playground.repo epel-testing.repo epel-modular.repo epel-next.repo epel-testing-modular.repo epel.repo 查找keepalived: [root@master yum.repos.d]# cd [root@master ~]# dnf list all |grep keepalived Failed to set locale, defaulting to C.UTF-8 Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] keepalived.x86_64 2.1.5-6.el8 AppStream 安装keepalived: [root@master ~]# dnf -y install keepalived 查看配置文件: [root@master ~]# ls /etc/keepalived/ keepalived.conf 查看安装生成的文件: [root@master ~]# rpm -ql keepalived /etc/keepalived //配置目录 /etc/keepalived/keepalived.conf //此为主配置文件 /etc/sysconfig/keepalived /usr/bin/genhash /usr/lib/.build-id /usr/lib/.build-id/0a /usr/lib/.build-id/0a/410997e11c666114ca6d785e58ff0cc248744e /usr/lib/.build-id/6f /usr/lib/.build-id/6f/ba0d6bad6cb5ff7b074e703849ed93bebf4a0f /usr/lib/systemd/system/keepalived.service //此为服务控制文件 /usr/libexec/keepalived /usr/sbin/keepalived /usr/share/doc/keepalived /usr/share/doc/keepalived/AUTHOR /usr/share/doc/keepalived/CONTRIBUTORS /usr/share/doc/keepalived/COPYING /usr/share/doc/keepalived/ChangeLog /usr/share/doc/keepalived/README /usr/share/doc/keepalived/TODO /usr/share/doc/keepalived/keepalived.conf.HTTP_GET.port /usr/share/doc/keepalived/keepalived.conf.IPv6 /usr/share/doc/keepalived/keepalived.conf.PING_CHECK /usr/share/doc/keepalived/keepalived.conf.SMTP_CHECK /usr/share/doc/keepalived/keepalived.conf.SSL_GET /usr/share/doc/keepalived/keepalived.conf.SYNOPSIS /usr/share/doc/keepalived/keepalived.conf.UDP_CHECK /usr/share/doc/keepalived/keepalived.conf.conditional_conf /usr/share/doc/keepalived/keepalived.conf.fwmark /usr/share/doc/keepalived/keepalived.conf.inhibit /usr/share/doc/keepalived/keepalived.conf.misc_check /usr/share/doc/keepalived/keepalived.conf.misc_check_arg /usr/share/doc/keepalived/keepalived.conf.quorum /usr/share/doc/keepalived/keepalived.conf.sample /usr/share/doc/keepalived/keepalived.conf.status_code /usr/share/doc/keepalived/keepalived.conf.track_interface /usr/share/doc/keepalived/keepalived.conf.virtual_server_group /usr/share/doc/keepalived/keepalived.conf.virtualhost /usr/share/doc/keepalived/keepalived.conf.vrrp /usr/share/doc/keepalived/keepalived.conf.vrrp.localcheck /usr/share/doc/keepalived/keepalived.conf.vrrp.lvs_syncd /usr/share/doc/keepalived/keepalived.conf.vrrp.routes /usr/share/doc/keepalived/keepalived.conf.vrrp.rules /usr/share/doc/keepalived/keepalived.conf.vrrp.scripts /usr/share/doc/keepalived/keepalived.conf.vrrp.static_ipaddress /usr/share/doc/keepalived/keepalived.conf.vrrp.sync /usr/share/man/man1/genhash.1.gz /usr/share/man/man5/keepalived.conf.5.gz /usr/share/man/man8/keepalived.8.gz /usr/share/snmp/mibs/KEEPALIVED-MIB.txt /usr/share/snmp/mibs/VRRP-MIB.txt /usr/share/snmp/mibs/VRRPv3-MIB.txt 用同样的方法在备服务器上安装keepalived
关闭防火墙: [root@backup ~]# systemctl stop firewalld.service [root@backup ~]# vim /etc/selinux/config SELINUX=disabled [root@backup ~]# setenforce 0 [root@backup ~]# systemctl disable --now firewalld.service Removed /etc/systemd/system/multi-user.target.wants/firewalld.service. Removed /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service. 配置网络源: [root@backup ~]# dnf -y install wget [root@backup ~]# cd /etc/yum.repos.d/ [root@backup yum.repos.d]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo [root@backup yum.repos.d]#sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo 安装epel源 [root@backup yum.repos.d]#dnf install -y https://mirrors.aliyun.com/epel/epel-release-latest-8.noarch.rpm [root@backup yum.repos.d]#sed -i 's|^#baseurl=https://download.example/pub|baseurl=https://mirrors.aliyun.com|' /etc/yum.repos.d/epel* [root@backup yum.repos.d]#sed -i 's|^metalink|#metalink|' /etc/yum.repos.d/epel* [root@backup yum.repos.d]# ls CentOS-Base.repo epel-next-testing.repo epel-playground.repo epel-testing.repo epel-modular.repo epel-next.repo epel-testing-modular.repo epel.repo 查找keepalived: [root@backup yum.repos.d]# cd [root@backup ~]# dnf list all |grep keepalived Failed to set locale, defaulting to C.UTF-8 Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] Module yaml error: Unexpected key in data: static_context [line 9 col 3] keepalived.x86_64 2.1.5-6.el8 AppStream 安装keepalived: [root@backup ~]# dnf -y install keepalived 查看配置文件: [root@backup ~]# ls /etc/keepalived/ keepalived.conf 查看安装生成的文件: [root@backup ~]# rpm -ql keepalived /etc/keepalived //配置目录 /etc/keepalived/keepalived.conf //此为主配置文件 /etc/sysconfig/keepalived /usr/bin/genhash /usr/lib/.build-id /usr/lib/.build-id/0a /usr/lib/.build-id/0a/410997e11c666114ca6d785e58ff0cc248744e /usr/lib/.build-id/6f /usr/lib/.build-id/6f/ba0d6bad6cb5ff7b074e703849ed93bebf4a0f /usr/lib/systemd/system/keepalived.service //此为服务控制文件 /usr/libexec/keepalived /usr/sbin/keepalived /usr/share/doc/keepalived /usr/share/doc/keepalived/AUTHOR /usr/share/doc/keepalived/CONTRIBUTORS /usr/share/doc/keepalived/COPYING /usr/share/doc/keepalived/ChangeLog /usr/share/doc/keepalived/README /usr/share/doc/keepalived/TODO /usr/share/doc/keepalived/keepalived.conf.HTTP_GET.port /usr/share/doc/keepalived/keepalived.conf.IPv6 /usr/share/doc/keepalived/keepalived.conf.PING_CHECK /usr/share/doc/keepalived/keepalived.conf.SMTP_CHECK /usr/share/doc/keepalived/keepalived.conf.SSL_GET /usr/share/doc/keepalived/keepalived.conf.SYNOPSIS /usr/share/doc/keepalived/keepalived.conf.UDP_CHECK /usr/share/doc/keepalived/keepalived.conf.conditional_conf /usr/share/doc/keepalived/keepalived.conf.fwmark /usr/share/doc/keepalived/keepalived.conf.inhibit /usr/share/doc/keepalived/keepalived.conf.misc_check /usr/share/doc/keepalived/keepalived.conf.misc_check_arg /usr/share/doc/keepalived/keepalived.conf.quorum /usr/share/doc/keepalived/keepalived.conf.sample /usr/share/doc/keepalived/keepalived.conf.status_code /usr/share/doc/keepalived/keepalived.conf.track_interface /usr/share/doc/keepalived/keepalived.conf.virtual_server_group /usr/share/doc/keepalived/keepalived.conf.virtualhost /usr/share/doc/keepalived/keepalived.conf.vrrp /usr/share/doc/keepalived/keepalived.conf.vrrp.localcheck /usr/share/doc/keepalived/keepalived.conf.vrrp.lvs_syncd /usr/share/doc/keepalived/keepalived.conf.vrrp.routes /usr/share/doc/keepalived/keepalived.conf.vrrp.rules /usr/share/doc/keepalived/keepalived.conf.vrrp.scripts /usr/share/doc/keepalived/keepalived.conf.vrrp.static_ipaddress /usr/share/doc/keepalived/keepalived.conf.vrrp.sync /usr/share/man/man1/genhash.1.gz /usr/share/man/man5/keepalived.conf.5.gz /usr/share/man/man8/keepalived.8.gz /usr/share/snmp/mibs/KEEPALIVED-MIB.txt /usr/share/snmp/mibs/VRRP-MIB.txt /usr/share/snmp/mibs/VRRPv3-MIB.txt 在主备机上分别安装nginx
在master上安装nginx
[root@master ~]# dnf -y install nginx [root@master ~]# cd /usr/share/nginx/html/ [root@master html]# ls 404.html 50x.html index.html nginx-logo.png poweredby.png [root@master html]# echo 'master' > index.html [root@master html]# systemctl start nginx [root@master html]# ss -antl State Recv-Q Send-Q Local Address:Port Peer Address:Port Process LISTEN 0 128 0.0.0.0:111 0.0.0.0:* LISTEN 0 128 0.0.0.0:80 0.0.0.0:* LISTEN 0 32 192.168.122.1:53 0.0.0.0:* LISTEN 0 128 0.0.0.0:22 0.0.0.0:* LISTEN 0 128 [::]:111 [::]:* LISTEN 0 128 [::]:80 [::]:* LISTEN 0 128 [::]:22 [::]:* [root@master html]# systemctl enable nginx Created symlink /etc/systemd/system/multi-user.target.wants/nginx.service → /usr/lib/systemd/system/nginx.service. //在主节点这边需要设置开机自启 在backup上安装nginx
[root@backup ~]# dnf -y install nginx [root@backup ~]# cd /usr/share/nginx/html/ [root@backup html]# ls 404.html 50x.html index.html nginx-logo.png poweredby.png [root@backup html]# echo 'backup' > index.html root@backup html]# systemctl start nginx [root@backup html]# ss -antl State Recv-Q Send-Q Local Address:Port Peer Address:Port Process LISTEN 0 128 0.0.0.0:22 0.0.0.0:* LISTEN 0 128 0.0.0.0:80 0.0.0.0:* LISTEN 0 128 [::]:22 [::]:* LISTEN 0 128 [::]:80 [::]:* //在备节点这边不需要设置开机自启 在浏览器上访问试试，确保master上的nginx服务能够正常访问
keepalived配置
配置主keepalived
[root@master html]# cd /etc/keepalived/ [root@master keepalived]# ls keepalived.conf [root@master keepalived]# mv keepalived.conf{,-bak} [root@master keepalived]# ls keepalived.conf-bak //备份一下配置文件 [root@master keepalived]# dnf -y install vim [root@master keepalived]# vim keepalived.conf //编辑一个新配置文件 [root@master keepalived]# cat keepalived.conf ! Configuration File for keepalived global_defs { router_id lb01 } vrrp_instance VI_1 { //这里主备节点需要一致 state BACKUP interface ens33 //网卡 virtual_router_id 51 priority 100 //这里比备节点的高 advert_int 1 authentication { auth_type PASS auth_pass tushanbu //密码(可以随机生成) } virtual_ipaddress { 192.168.222.133 //高可用虚拟IP（VIP）地址 } } virtual_server 192.168.222.133 80 { delay_loop 6 lb_algo rr lb_kind DR persistence_timeout 50 protocol TCP real_server 192.168.222.138 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.222.139 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } } [root@master keepalived]# ls keepalived.conf keepalived.conf-bak [root@master keepalived]# systemctl enable --now keepalived Created symlink /etc/systemd/system/multi-user.target.wants/keepalived.service → /usr/lib/systemd/system/keepalived.service. [root@master keepalived]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:f6:83:57 brd ff:ff:ff:ff:ff:ff inet 192.168.222.138/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet 192.168.222.133/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fef6:8357/64 scope link valid_lft forever preferred_lft forever 3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff //此时备节点的keepalived还没有启动 [root@master keepalived]# scp keepalived.conf 192.168.222.139:/etc/keepalived The authenticity of host '192.168.222.139 (192.168.222.139)' can't be established. ECDSA key fingerprint is SHA256:anVVbTlEIzA1E8rB7IbLzaf7t9oQjB0qFP6Dd/ijnJI. Are you sure you want to continue connecting (yes/no/[fingerprint])? yes Warning: Permanently added '192.168.222.139' (ECDSA) to the list of known hosts. root@192.168.222.139's password: keepalived.conf 100% 875 905.2KB/s 00:00 //将创建的这个配置文件传到备节点上去，因为主,备节点的这个配置文件基本上都是一样的只需要改一点点 配置备keepalived
[root@backup html]# cd /etc/keepalived/ [root@backup keepalived]# ls keepalived.conf [root@backup keepalived]# mv keepalived.conf{,-bak} [root@backup keepalived]# ls keepalived.conf-bak //备份一下配置文件 [root@backup keepalived]# dnf -y install vim [root@backup keepalived]# ls //接收到主节点传过来的配置文件 keepalived.conf keepalived.conf-bak [root@backup keepalived]# vim keepalived.conf //进行修改一下 [root@backup keepalived]# cat keepalived.conf ! Configuration File for keepalived global_defs { router_id lb02 } vrrp_instance VI_1 { //这里主备节点需要一致 state BACKUP interface ens33 //网卡 virtual_router_id 51 priority 90 //这里比主节点的小 advert_int 1 authentication { auth_type PASS auth_pass tushanbu //密码(可以随机生成) } virtual_ipaddress { 192.168.222.133 //高可用虚拟IP（VIP）地址 } } virtual_server 192.168.222.133 80 { delay_loop 6 lb_algo rr lb_kind DR persistence_timeout 50 protocol TCP real_server 192.168.222.138 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.222.139 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } } [root@backup keepalived]# systemctl enable --now keepalived Created symlink /etc/systemd/system/multi-user.target.wants/keepalived.service → /usr/lib/systemd/system/keepalived.service. 查看VIP在哪里
在MASTER上查看
[root@master keepalived]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:f6:83:57 brd ff:ff:ff:ff:ff:ff inet 192.168.222.138/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet 192.168.222.133/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fef6:8357/64 scope link valid_lft forever preferred_lft forever 3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff //主节点上面有vip 在BACKUP上查看
[root@backup keepalived]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:31:af:f9 brd ff:ff:ff:ff:ff:ff inet 192.168.222.139/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fe31:aff9/64 scope link valid_lft forever preferred_lft forever //备节点上面没有vip 测试
停掉master的keepalived服务，开启backup的niginx和keepalived服务然后查看主权情况
master
[root@master keepalived]# systemctl stop keepalived.service backup:
[root@backup keepalived]# systemctl start nginx.service [root@backup keepalived]# systemctl start keepalived.service [root@backup keepalived]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:31:af:f9 brd ff:ff:ff:ff:ff:ff inet 192.168.222.139/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet 192.168.222.133/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fe31:aff9/64 scope link valid_lft forever preferred_lft forever 
//此时可以看见backup是主
然后再开启master的keepalived服务再查看主权情况
master
[root@master keepalived]# systemctl start keepalived.service [root@master keepalived]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:f6:83:57 brd ff:ff:ff:ff:ff:ff inet 192.168.222.138/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet 192.168.222.133/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fef6:8357/64 scope link valid_lft forever preferred_lft forever 3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff backup
[root@backup keepalived]# systemctl stop nginx.service //此时测试的时候backup上面的nginx是要进行关闭的 [root@backup keepalived]# ss -antl State Recv-Q Send-Q Local Address:Port Peer Address:Port Process LISTEN 0 128 0.0.0.0:22 0.0.0.0:* LISTEN 0 128 [::]:22 [::]:* [root@backup keepalived]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:31:af:f9 brd ff:ff:ff:ff:ff:ff inet 192.168.222.139/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fe31:aff9/64 scope link valid_lft forever preferred_lft forever 
//此时可以看见master还是主
让keepalived监控nginx负载均衡机
keepalived通过脚本来监控nginx负载均衡机的状态
在master上编写脚本
[root@master keepalived]# cd [root@master ~]# mkdir /scripts [root@master ~]# cd /scripts/ [root@master scripts]# vim check_nginx.sh [root@master scripts]# cat check_nginx.sh #!/bin/bash nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep 'bnginxb'|wc -l) if [ $nginx_status -lt 1 ];then systemctl stop keepalived fi [root@master scripts]# chmod +x check_nginx.sh [root@master scripts]# ll total 4 -rwxr-xr-x. 1 root root 142 Oct 8 23:21 check_nginx.sh [root@master scripts]# vim notify.sh [root@master scripts]# cat notify.sh #!/bin/bash case "$1" in master) nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep 'bnginxb'|wc -l) if [ $nginx_status -lt 1 ];then systemctl start nginx fi ;; backup) nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep 'bnginxb'|wc -l) if [ $nginx_status -gt 0 ];then systemctl stop nginx fi ;; *) echo "Usage:$0 master|backup VIP" ;; esac [root@master scripts]# chmod +x notify.sh [root@master scripts]# ll total 8 -rwxr-xr-x. 1 root root 142 Oct 8 23:21 check_nginx.sh -rwxr-xr-x. 1 root root 383 Oct 8 23:31 notify.sh [root@master scripts]# scp check_nginx.sh 192.168.222.139:/scripts/ root@192.168.222.139's password: check_nginx.sh 100% 142 113.6KB/s 00:00 [root@master scripts]# scp notify.sh 192.168.222.139:/scripts/ root@192.168.222.139's password: notify.sh 100% 383 244.7KB/s 00:00 //将这个脚本传给备节点上提前创建好的目录里面 在backup上编写脚本
[root@backup keepalived]# cd [root@backup ~]# mkdir /scripts [root@backup ~]# cd /scripts/ [root@backup scripts]# ll total 8 -rwxr-xr-x. 1 root root 142 Oct 8 23:39 check_nginx.sh -rwxr-xr-x. 1 root root 383 Oct 8 23:36 notify.sh 配置keepalived加入监控脚本的配置
配置主keepalived
[root@master scripts]# cd [root@master ~]# vim /etc/keepalived/keepalived.conf [root@master ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id lb01 } vrrp_script nginx_check { //添加这一部分 script "/scripts/check_nginx.sh" interval 5 weight -20 } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass tushanbu } virtual_ipaddress { 192.168.222.133 } track_script { //添加这一部分 nginx_check } notify_master "/scripts/notify.sh master 192.168.222.133" notify_backup "/scripts/notify.sh backup 192.168.222.133" } virtual_server 192.168.222.133 80 { delay_loop 6 lb_algo rr lb_kind DR persistence_timeout 50 protocol TCP real_server 192.168.222.138 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.222.139 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } } [root@master ~]# systemctl restart keepalived.service [root@master ~]# systemctl restart nginx.service 配置备keepalived
backup无需检测nginx是否正常，当升级为MASTER时启动nginx，当降级为BACKUP时关闭
[root@backup scripts]# cd [root@backup ~]# vim /etc/keepalived/keepalived.conf [root@backup ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id lb02 } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 priority 90 advert_int 1 authentication { auth_type PASS auth_pass tushanbu } virtual_ipaddress { 192.168.222.133 } notify_master "/scripts/notify.sh master 192.168.222.133" //添加 notify_backup "/scripts/notify.sh backup 192.168.222.133" //添加 } virtual_server 192.168.222.133 80 { delay_loop 6 lb_algo rr lb_kind DR persistence_timeout 50 protocol TCP real_server 192.168.222.138 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.222.139 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } } [root@backup ~]# systemctl restart keepalived.service [root@backup ~]# systemctl restart nginx.service 测试
正常状态运行查看状态
master: [root@master ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:f6:83:57 brd ff:ff:ff:ff:ff:ff inet 192.168.222.138/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet 192.168.222.133/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fef6:8357/64 scope link valid_lft forever preferred_lft forever 3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff [root@master ~]# curl 192.168.222.133 master backup: [root@backup ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:31:af:f9 brd ff:ff:ff:ff:ff:ff inet 192.168.222.139/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fe31:aff9/64 scope link valid_lft forever preferred_lft forever 停止nginx [root@master ~]# systemctl stop nginx.service [root@master ~]# ss -antl State Recv-Q Send-Q Local Address:Port Peer Address:Port Process LISTEN 0 128 0.0.0.0:111 0.0.0.0:* LISTEN 0 32 192.168.122.1:53 0.0.0.0:* LISTEN 0 128 0.0.0.0:22 0.0.0.0:* LISTEN 0 128 [::]:111 [::]:* LISTEN 0 128 [::]:22 [::]:* master上停止nginx后的状态
master： [root@master ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:f6:83:57 brd ff:ff:ff:ff:ff:ff inet 192.168.222.138/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fef6:8357/64 scope link valid_lft forever preferred_lft forever 3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000 link/ether 52:54:00:db:51:2f brd ff:ff:ff:ff:ff:ff backup: [root@backup ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 00:0c:29:31:af:f9 brd ff:ff:ff:ff:ff:ff inet 192.168.222.139/24 brd 192.168.222.255 scope global noprefixroute ens33 valid_lft forever preferred_lft forever inet 192.168.222.133/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fe31:aff9/64 scope link valid_lft forever preferred_lft forever [root@backup ~]# curl 192.168.222.133 backup 
