keepalived高可用
keepalived高可用
目录
keepalived简介
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官网
keepalived的重要功能
keepalived 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
keepalived 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）作为系统keepalived 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）网络服务的高可用性（failover）
keepalived高可用故障转移的原理
Keepalived 高可用服务之间的故障切换转移，是通过 VRRP (Virtual Router Redundancy Protocol ,虚拟路由器冗余协议）来实现的。
在 Keepalived 服务正常工作时，主 Master 节点会不断地向备节点发送（多播的方式）心跳消息，用以告诉备 Backup 节点自己还活看，当主 Master 节点发生故障时，就无法发送心跳消息，备节点也就因此无法继续检测到来自主 Master 节点的心跳了，于是调用自身的接管程序，接管主 Master 节点的 IP 资源及服务。而当主 Master 节点恢复时，备 Backup 节点又会释放主节点故障时自身接管的IP资源及服务，恢复到原来的备用角色。
什么是VRRP
VRRP ,全 称 Virtual Router Redundancy Protocol ,中文名为虚拟路由冗余协议 ，VRRP的出现就是为了解决静态踣甶的单点故障问题，VRRP是通过一种竞选机制来将路由的任务交给某台VRRP路由器的。
keepalived配置文件
keepalived 的主配置文件是 /etc/keepalived/keepalived.conf。其内容如下：
[root@master ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs { //全局配置
notification_email { //定义报警收件人邮件地址
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc //定义报警发件人邮箱
smtp_server 192.168.118.1 //邮箱服务器地址
smtp_connect_timeout 30 //定义邮箱超时时间
router_id LVS_DEVEL //定义路由标识信息，同局域网内唯一
vrrp_skip_check_adv_addr
vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_instance VI_1 { //定义实例
state MASTER //指定keepalived节点的初始状态，可选值为MASTER|BACKUP
interface eth0 //VRRP实例绑定的网卡接口，用户发送VRRP包
virtual_router_id 51 //虚拟路由的ID，同一集群要一致
priority 100 //定义优先级，按优先级来决定主备角色，优先级越大越优先
nopreempt //设置不抢占
advert_int 1 //主备通讯时间间隔
authentication { //配置认证
auth_type PASS //认证方式，此处为密码
auth_pass 1111 //同一集群中的keepalived配置里的此处必须一致，推荐使用8位随机数
}
virtual_ipaddress { //配置要使用的VIP地址
192.168.118.16
}
}
virtual_server 192.168.118.16 1358 { //配置虚拟服务器
delay_loop 6 //健康检查的时间间隔
lb_algo rr //lvs调度算法
lb_kind NAT //lvs模式
persistence_timeout 50 //持久化超时时间，单位是秒
protocol TCP //4层协议
sorry_server 192.168.118.200 1358 //定义备用服务器，当所有RS都故障时用sorry_server来响应客户端
real_server 192.168.118.2 1358 { //定义真实处理请求的服务器
weight 1 //给服务器指定权重，默认为1
HTTP_GET {
url {
path /testurl/test.jsp //指定要检查的URL路径
digest 640205b7b0fc66c1ea91c463fac6334d //摘要信息
}
url {
path /testurl2/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
url {
path /testurl3/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
connect_timeout 3 //连接超时时间
nb_get_retry 3 //get尝试次数
delay_before_retry 3 //在尝试之前延迟多长时间
}
}
real_server 192.168.118.3 1358 {
weight 1
HTTP_GET {
url {
path /testurl/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334c
}
url {
path /testurl2/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334c
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
定制主配置文件
vrrp_instance段配置
nopreempt //设置为不抢占。默认是抢占的，当高优先级的机器恢复后，会抢占低优先 \
级的机器成为MASTER，而不抢占，则允许低优先级的机器继续成为MASTER，即使高优先级 \
的机器已经上线。如果要使用这个功能，则初始化状态必须为BACKUP。
preempt_delay //设置抢占延迟。单位是秒，范围是0---1000，默认是0.发现低优先 \
级的MASTER后多少秒开始抢占。
vrrp_script段配置
//作用：添加一个周期性执行的脚本。脚本的退出状态码会被调用它的所有的VRRP Instance记录。
//注意：至少有一个VRRP实例调用它并且优先级不能为0.优先级范围是1-254.
vrrp_script <SCRIPT_NAME> {
...
}
//选项说明：
script "/path/to/somewhere" //指定要执行的脚本的路径。
interval <INTEGER> //指定脚本执行的间隔。单位是秒。默认为1s。
timeout <INTEGER> //指定在多少秒后，脚本被认为执行失败。
weight <-254 --- 254> //调整优先级。默认为2.
rise <INTEGER> //执行成功多少次才认为是成功。
fall <INTEGER> //执行失败多少次才认为失败。
user <USERNAME> [GROUPNAME] //运行脚本的用户和组。
init_fail //假设脚本初始状态是失败状态。
//weight说明：
1. 如果脚本执行成功(退出状态码为0)，weight大于0，则priority增加。
2. 如果脚本执行失败(退出状态码为非0)，weight小于0，则priority减少。
3. 其他情况下，priority不变。
real_server段配置
weight <INT> //给服务器指定权重。默认是1
inhibit_on_failure //当服务器健康检查失败时，将其weight设置为0， \
//而不是从Virtual Server中移除
notify_up <STRING> //当服务器健康检查成功时，执行的脚本
notify_down <STRING> //当服务器健康检查失败时，执行的脚本
uthreshold <INT> //到这台服务器的最大连接数
lthreshold <INT> //到这台服务器的最小连接数
tcp_check段配置
connect_ip <IP ADDRESS> //连接的IP地址。默认是real server的ip地址
connect_port <PORT> //连接的端口。默认是real server的端口
bindto <IP ADDRESS> //发起连接的接口的地址。
bind_port <PORT> //发起连接的源端口。
connect_timeout <INT> //连接超时时间。默认是5s。
fwmark <INTEGER> //使用fwmark对所有出去的检查数据包进行标记。
warmup <INT> //指定一个随机延迟，最大为N秒。可防止网络阻塞。如果为0，则关闭该功能。
retry <INIT> //重试次数。默认是1次。
delay_before_retry <INT> //默认是1秒。在重试之前延迟多少秒。
keepalived实现nginx高可用
环境介绍
| 主机名 | ip |
|---|---|
| master | 192.168.118.129 |
| backup | 192.168.118.128 |
准备工作
master
#修改master主机名
[root@localhost ~]# hostnamectl set-hostname master
[root@localhost ~]# bash
#关闭防火墙和selinux
[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.
[root@master ~]# setenforce 0
[root@master ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@backup ~]# reboot
backup
#修改backup主机名
[root@localhost ~]# hostnamectl set-hostname backup
[root@localhost ~]# bash
#关闭防火墙和selinux
[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.
[root@backup ~]# setenforce 0
[root@backup ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@backup ~]# reboot
安装并配置nginx
master配置nginx
[root@master ~]# yum -y install nginx
[root@master ~]# cd /usr/share/nginx/html/
[root@master html]# mv index.html{,.bak}
[root@master html]# echo 'master' > index.html //备份配置原配置文件
[root@master html]# cat index.html
master
[root@master ~]# systemctl start nginx.service //开启nginx
[root@master ~]# curl 192.168.118.129
master
backup配置nginx
[root@backup ~]# yum -y install nginx
[root@backup ~]# cd /usr/share/nginx/html/
[root@backup html]# mv index.html{,.bak}
[root@backup html]# echo 'backup' > index.html
[root@backup html]# cat index.html
backup
[root@backup]# systemctl start nginx.service
[root@backup]# curl 192.168.118.128
backup
安装并配置keepalived
master安装配置keepalived
[root@master ~]# yum -y install keepalived
[root@master ~]# cd /etc/keepalived/
[root@master keepalived]# vim keepalived.conf
[root@master keepalived]# cat keepalived.conf
! Configuration File for keepalived
global_defs {
router_id lb01
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.118.250
}
}
virtual_server 192.168.118.250 80 {
delay_loop 6
lb_algo rr
lb_kind NAT
persistence_timeout 50
protocol TCP
real_server 192.168.118.129 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.118.128 80 {
weight 1keepa
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
#启动keepalived
[root@master ~]# systemctl start keepalived.service
[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:b5:9a:13 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.129/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1121sec preferred_lft 1121sec
inet 192.168.118.250/32 scope global ens33 //当keepalived启动后 会生成vip
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feb5:9a13/64 scope link noprefixroute
valid_lft forever preferred_lft forever
backup安装配置keepalived
[root@backup ~]# yum -y install keepalived
[root@master ~]# cd /etc/keepalived/
[root@master keepalived]# vim keepalived.conf
[root@master keepalived]# cat keepalived.conf
! Configuration File for keepalived
global_defs {
router_id lb02
}
vrrp_instance VI_1 {
state BACKUP //修改为backup
interface ens33
virtual_router_id 51
priority 90 //修改优先级 因为是备 所以优先级更低
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.118.250
}
}
virtual_server 192.168.118.250 80 {
delay_loop 6
lb_algo rr
lb_kind NAT
persistence_timeout 50
protocol TCP
real_server 192.168.118.129 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.118.128 80 {
weight 1keepa
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
[root@backup ~]# systemctl start keepalived.service
[root@backup ~]# ip a //因为优先级低 所以没有vip
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:29:16:02:99 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.128/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1140sec preferred_lft 1140sec
inet6 fe80::20c:29ff:fe16:299/64 scope link noprefixroute
valid_lft forever preferred_lft forever
访问测试
master在浏览器上使用vip进行访问
正常情况下主(master)的keepalived和nginx都是开启的,备(backup)的nginx是关闭的
[root@backup ~]# systemctl stop nginx
backup在浏览器上使用vip进行访问
关闭master主机的keepalived服务
[root@master ~]# systemctl stop keepalived.service
这时backup主机生成了vip
[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:29:16:02:99 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.128/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1735sec preferred_lft 1735sec
inet 192.168.118.250/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe16:299/64 scope link noprefixroute
valid_lft forever preferred_lft forever
[root@backup ~]# systemctl start nginx //开启nginx
在浏览器中访问
配置脚本
恢复环境
正常情况下主(master)的keepalived和nginx都是开启的,备(backup)的nginx是关闭的
[root@master ~]# systemctl start keepalived.service //启动master的keepalived服务
[root@backup ~]# systemctl stop nginx //关闭backup的nginx服务
master编写脚本
此脚本用于控制keepalived是否关闭，当master的nginx异常，而关闭时就自动关闭keepalived服务以便让backup能获得vip
[root@master ~]# mkdir /scripts
[root@master ~]# cd /scripts/
[root@master scripts]# touch check_m.sh
[root@master scripts]# vim check_m.sh
#!/bin/bash
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -lt 1 ];then
systemctl stop keepalived
fi
[root@master scripts]# chmod +x check_m.sh
[root@master scripts]# ll
total 4
-rwxr-xr-x 1 root root 145 Oct 9 00:29 check_m.sh
此脚本用于检查主机是否为master和backup 来控制nginx是否关闭和开启
[root@master scripts]# touch notify.sh
[root@master scripts]# vim notify.sh
[root@backup scripts]# cat notify.sh
#!/bin/bash
VIP=$2
#sendmail (){ //注释内容为异常时发送邮件，实验并不需要
# subject="${VIP}'s server keepalived state is translate"
# content="`date +'%F %T'`: `hostname`'s state change to master"
# echo $content | mail -s "$subject" **********@qq.com
#}
case "$1" in
master)
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -lt 1 ];then
systemctl start nginx
fi
sendmail
;;
backup)
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|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 145 Oct 9 00:29 check_m.sh
-rwxr-xr-x 1 root root 572 Oct 9 00:36 notify.sh
backup编写脚本
[root@backup ~]# mkdir /scripts
[root@backup ~]# cd /scripts/
[root@backup scripts]# touch notify.sh
[root@backup scripts]# vim notify.sh
[root@backup scripts]# cat notify.sh
#!/bin/bash
VIP=$2
#sendmail (){
# subject="${VIP}'s server keepalived state is translate"
# content="`date +'%F %T'`: `hostname`'s state change to master"
# echo $content | mail -s "$subject" **********@qq.com
#}
case "$1" in
master)
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -lt 1 ];then
systemctl start nginx
fi
sendmail
;;
backup)
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -gt 0 ];then
systemctl stop nginx
fi
;;
*)
echo "Usage:$0 master|backup VIP"
;;
esac
[root@backup scripts]# chmod +x notify.sh
[root@backup scripts]# ll
total 4
-rwxr-xr-x 1 root root 558 Oct 9 00:41 notify.sh
配置keepalived加入监控脚本的配置
主(master)配置keepalived
[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 { //添加此处
script "/scripts/check_m.sh"
interval 1
weight -20
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.118.250
}
track_script { //添加此处
nginx_check
}
notify_master "/scripts/notify.sh master 192.168.118.250"
}
virtual_server 192.168.118.250 80 {
delay_loop 6
lb_algo rr
lb_kind NAT
persistence_timeout 50
protocol TCP
real_server 192.168.118.129 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.118.128 80 {
weight 1keepa
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
[root@master ~]# systemctl restart keepalived.service //重启服务
备用(backup)配置keepalived
[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 123456
}
virtual_ipaddress {
192.168.118.250
}
notify_master "/scripts/notify.sh master 192.168.118.250"
notify_backup "/scripts/notify.sh backup 192.168.118.250"
}
virtual_server 192.168.118.250 80 {
delay_loop 6
lb_algo rr
lb_kind NAT
persistence_timeout 50
protocol TCP
real_server 192.168.118.129 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.118.128 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 //重启服务
实验
这时保证master主机nginx与keepalived服务都处于开启状态，backup主机nginx处于关闭keepalived处于开启状态
关闭master的nginx服务
[root@master ~]# systemctl stop nginx
[root@master ~]# ip a //vip消失了
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:b5:9a:13 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.129/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1294sec preferred_lft 1294sec
inet6 fe80::20c:29ff:feb5:9a13/64 scope link noprefixroute
valid_lft forever preferred_lft forever
当master的nginx服务异常时，backup抢占vip开启nginx服务
[root@backup ~]# systemctl status nginx
● nginx.service - The nginx HTTP and reverse proxy server
Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor pres>
Active: active (running) since Sun 2022-10-09 00:56:16 CST; 3min 42s ago
Process: 143804 ExecStart=/usr/sbin/nginx (code=exited, status=0/SUCCESS)
Process: 143802 ExecStartPre=/usr/sbin/nginx -t (code=exited, status=0/SUCCES>
Process: 143799 ExecStartPre=/usr/bin/rm -f /run/nginx.pid (code=exited, stat>
...省略
[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:29:16:02:99 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.128/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1070sec preferred_lft 1070sec
inet 192.168.118.250/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe16:299/64 scope link noprefixroute
valid_lft forever preferred_lft forever
浏览器这时应访问backup
正常情况下主的nginx和keepalived服务是开启的，备的nginx是关闭keeplived服务是开启的。当主的nginx服务异常时通过监控或者脚本用邮件发送告警信息给用户，当需要恢复主的服务时需要手动将主的nginx异常修复后并将nginx和keepalived服务重启，主就拥有了vip并可以正常访问到master
开启master的nginx服务和keepalived服务
[root@master ~]# systemctl start nginx
[root@master ~]# systemctl restart keepalived.service
[root@master ~]# ip a //重新获取到了vip
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:b5:9a:13 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.129/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1777sec preferred_lft 1777sec
inet 192.168.118.250/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feb5:9a13/64 scope link noprefixroute
valid_lft forever preferred_lft forever
浏览器这时应访问到master
keepalived实现haproxy负载均衡高可用
环境介绍
| 主机名 | ip | 服务 |
|---|---|---|
| master | 192.168.118.129 | haproxy keepalived |
| backup | 192.168.118.128 | haproxy keepalived |
| RS1 | 192.168.118.130 | nginx |
| RS2 | 192.168.118.131 | httpd |
准备工作
master
#修改master主机名
[root@localhost ~]# hostnamectl set-hostname master
[root@localhost ~]# bash
#关闭防火墙和selinux
[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.
[root@master ~]# setenforce 0
[root@master ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@backup ~]# reboot
backup
#修改backup主机名
[root@localhost ~]# hostnamectl set-hostname backup
[root@localhost ~]# bash
#关闭防火墙和selinux
[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.
[root@backup ~]# setenforce 0
[root@backup ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@backup ~]# reboot
RS1
#修改RS1主机名
[root@localhost ~]# hostnamectl set-hostname RS1
[root@localhost ~]# bash
#关闭防火墙和selinux
[root@RS1 ~]# systemctl disable --now firewalld.service
Removed /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@RS1 ~]# setenforce 0
[root@RS1 ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@RS1 ~]# reboot
#安装nginx服务，主页内容为web1
[root@RS1 ~]# dnf -y install nginx
[root@RS1 ~]# echo "web1" > /usr/share/nginx/html/index.html
[root@RS1 ~]# systemctl enable --now nginx.service
Created symlink /etc/systemd/system/multi-user.target.wants/nginx.service → /usr/lib/systemd/system/nginx.service.
[root@RS1 ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 128 0.0.0.0:80 0.0.0.0:*
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 128 [::]:80 [::]:*
LISTEN 0 128 [::]:22 [::]:*
[root@RS1 ~]# curl 192.168.118.130
web1
RS2
#修改RS2主机名
[root@localhost ~]# hostnamectl set-hostname RS2
[root@localhost ~]# bash
#关闭防火墙和selinux
[root@RS2 ~]# systemctl disable --now firewalld.service
Removed /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@RS2 ~]# setenforce 0
[root@RS2 ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@RS2 ~]# reboot
#安装httpd服务，主页内容为web2
[root@RS2 ~]# dnf -y install httpd
[root@RS2 ~]# echo "web2" > /var/www/html/index.html
[root@RS2 ~]# systemctl enable --now httpd.service
Created symlink /etc/systemd/system/multi-user.target.wants/httpd.service → /usr/lib/systemd/system/httpd.service.
[root@RS2 ~]# 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 *:80 *:*
LISTEN 0 128 [::]:22 [::]:*
[root@RS2 ~]# curl 192.168.118.131
web2
部署haproxy负载均衡
master
#创建用户
[root@master ~]# useradd -rMs /sbin/nologin haproxy
#下载依赖包
[root@master ~]# dnf -y install make gcc pcre-devel bzip2-devel openssl-devel systemd-devel wget vim
#下载haproxy压缩包
[root@master ~]# wget https://src.fedoraproject.org/repo/pkgs/haproxy/haproxy-2.6.0.tar.gz/sha512/7bb70bfb5606bbdac61d712bc510c5e8d5a5126ed8827d699b14a2f4562b3bd57f8f21344d955041cee0812c661350cca8082078afe2f277ff1399e461ddb7bb/haproxy-2.6.0.tar.gz
#解压并安装
[root@master ~]# tar -xf haproxy-2.6.0.tar.gz
[root@master ~]# cd haproxy-2.6.0
[root@master haproxy-2.6.0]# make -j $(grep 'processor' /proc/cpuinfo |wc -l) \
TARGET=linux-glibc \
USE_OPENSSL=1 \
USE_ZLIB=1 \
USE_PCRE=1 \
USE_SYSTEMD=1
[root@master haproxy-2.6.0]# make install PREFIX=/usr/local/haproxy
#复制命令到/usr/sbin目录下
[root@master haproxy-2.6.0]# cp haproxy /usr/sbin/
[root@master haproxy-2.6.0]# cd
#修改内核参数
[root@master ~]# vim /etc/sysctl.conf
...省略
net.ipv4.ip_nonlocal_bind = 1
net.ipv4.ip_forward = 1
[root@master ~]# sysctl -p
net.ipv4.ip_nonlocal_bind = 1
net.ipv4.ip_forward = 1
#修改配置文件
[root@master ~]# mkdir /etc/haproxy
[root@master ~]# vim /etc/haproxy/haproxy.cfg
global
daemon
maxconn 256
defaults
mode http
timeout connect 5000ms
timeout client 50000ms
timeout server 50000ms
frontend http-in
bind *:80
default_backend servers
backend servers
server web01 192.168.118.130:80
server web02 192.168.118.131:80
#编写service文件，并启动服务
[root@master ~]# vim /usr/lib/systemd/system/haproxy.service
[Unit]
Description=HAProxy Load Balancer
After=syslog.target network.target
[Service]
ExecStartPre=/usr/local/haproxy/sbin/haproxy -f /etc/haproxy/haproxy.cfg -c -q
ExecStart=/usr/local/haproxy/sbin/haproxy -Ws -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid
ExecReload=/bin/kill -USR2 $MAINPID
[Install]
WantedBy=multi-user.target
[root@master ~]# systemctl daemon-reload
[root@master ~]# systemctl start haproxy.service
[root@master ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 128 0.0.0.0:80 0.0.0.0:*
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 128 [::]:22 [::]:*
#查看负载均衡效果
[root@master ~]# curl 192.168.118.129
web1
[root@master ~]# curl 192.168.118.129
web2
[root@master ~]# curl 192.168.118.129
web1
[root@master ~]# curl 192.168.118.129
web2
backup
[root@backup ~]# dnf -y install nginx
#创建用户
[root@backup ~]# useradd -rMs /sbin/nologin haproxy
#下载依赖包
[root@backup ~]# dnf -y install make gcc pcre-devel bzip2-devel openssl-devel systemd-devel wget vim
#下载haproxy压缩包
[root@backup ~]# wget https://src.fedoraproject.org/repo/pkgs/haproxy/haproxy-2.6.0.tar.gz/sha512/7bb70bfb5606bbdac61d712bc510c5e8d5a5126ed8827d699b14a2f4562b3bd57f8f21344d955041cee0812c661350cca8082078afe2f277ff1399e461ddb7bb/haproxy-2.6.0.tar.gz
#解压并安装
[root@backup ~]# tar -xf haproxy-2.6.0.tar.gz
[root@backup ~]# cd haproxy-2.6.0
[root@backup haproxy-2.6.0]# make -j $(grep 'processor' /proc/cpuinfo |wc -l) \
TARGET=linux-glibc \
USE_OPENSSL=1 \
USE_ZLIB=1 \
USE_PCRE=1 \
USE_SYSTEMD=1
[root@backup haproxy-2.6.0]# make install PREFIX=/usr/local/haproxy
#复制命令到/usr/sbin目录下
[root@backup haproxy-2.6.0]# cp haproxy /usr/sbin/
[root@backup haproxy-2.6.0]# cd
#修改内核参数
[root@backup ~]# vim /etc/sysctl.conf
...省略
net.ipv4.ip_nonlocal_bind = 1
net.ipv4.ip_forward = 1
[root@backup ~]# sysctl -p
net.ipv4.ip_nonlocal_bind = 1
net.ipv4.ip_forward = 1
#修改配置文件
[root@backup ~]# mkdir /etc/haproxy
[root@backup ~]# vim /etc/haproxy/haproxy.cfg
global
daemon
maxconn 256
defaults
mode http
timeout connect 5000ms
timeout client 50000ms
timeout server 50000ms
frontend http-in
bind *:80
default_backend servers
backend servers
server web01 192.168.118.130:80
server web02 192.168.118.131:80
#编写service文件，并启动服务
[root@backup ~]# vim /usr/lib/systemd/system/haproxy.service
[Unit]
Description=HAProxy Load Balancer
After=syslog.target network.target
[Service]
ExecStartPre=/usr/local/haproxy/sbin/haproxy -f /etc/haproxy/haproxy.cfg -c -q
ExecStart=/usr/local/haproxy/sbin/haproxy -Ws -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid
ExecReload=/bin/kill -USR2 $MAINPID
[Install]
WantedBy=multi-user.target
[root@backup ~]# systemctl daemon-reload
[root@backup ~]# systemctl start haproxy.service
[root@backup ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 128 0.0.0.0:80 0.0.0.0:*
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 128 [::]:22 [::]:*
#查看负载均衡效果
[root@backup ~]# curl 192.168.118.128
web1
[root@backup ~]# curl 192.168.118.128
web2
[root@backup ~]# curl 192.168.118.128
web1
[root@backup ~]# curl 192.168.118.128
web2
#backup端的负载均衡器最好关掉
[root@backup ~]# systemctl stop haproxy.service
部署keepalived高可用
master
#首先安装keepalived
[root@master ~]# dnf -y install keepalived
#编辑配置文件
[root@master ~]# vim /etc/keepalived/keepalived.conf
[root@master ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id lb01
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.118.250
}
}
virtual_server 192.168.118.250 80 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 50
protocol TCP
real_server 192.168.118.129 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.118.128 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
#并启动服务
[root@master ~]# systemctl start keepalived.service
#通过虚拟ip访问
[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:b5:9a:13 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.129/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1066sec preferred_lft 1066sec
inet 192.168.118.250/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feb5:9a13/64 scope link noprefixroute
valid_lft forever preferred_lft forever
[root@master ~]# curl 192.168.118.250
web1
[root@master ~]# curl 192.168.118.250
web2
[root@master ~]# curl 192.168.118.250
web1
[root@master ~]# curl 192.168.118.250
web2
backup
#首先安装keepalived
[root@backup ~]# dnf -y install keepalived
#编辑配置文件
[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 123456
}
virtual_ipaddress {
192.168.118.250
}
}
virtual_server 192.168.118.250 80 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 50
protocol TCP
real_server 192.168.118.129 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.118.128 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
#启动服务
[root@backup ~]# systemctl start keepalived.service
编写脚本
master
[root@master ~]# mkdir /scripts
[root@master ~]# cd /scripts/
[root@master scripts]# vim check_haproxy.sh
#!/bin/bash
haproxy_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bhaproxy\b'|wc -l)
if [ $haproxy_status -lt 1 ];then
systemctl stop keepalived
fi
[root@master scripts]# vim notify.sh
#!/bin/bash
VIP=$2
case "$1" in
master)
haproxy_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bhaproxy\b'|wc -l)
if [ $haproxy_status -lt 1 ];then
systemctl start haproxy
fi
;;
backup)
haproxy_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bhaproxy\b'|wc -l)
if [ $haproxy_status -gt 0 ];then
systemctl stop haproxy
fi
;;
esac
[root@master scripts]# chmod +x check_haproxy.sh notify.sh
[root@master scripts]# ll
total 8
-rwxr-xr-x 1 root root 145 Oct 10 00:32 check_haproxy.sh
-rwxr-xr-x 1 root root 328 Oct 10 00:38 notify.sh
backup
[root@backup ~]# mkdir /scripts
[root@backup ~]# cd /scripts/
[root@backup scripts]# scp root@192.168.118.129:/scripts/notify.sh .
The authenticity of host '192.168.118.129 (192.168.118.129)' can't be established.
ECDSA key fingerprint is SHA256:+RwKWt1ErJuzJKcNeLslD46lbAtIO3wmNQk9BhIrtxs.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '192.168.118.129' (ECDSA) to the list of known hosts.
root@192.168.118.129's password:
notify.sh 100% 328 353.0KB/s 00:00
[root@backup scripts]# ll
total 4
-rwxr-xr-x 1 root root 328 Oct 10 00:41 notify.sh
配置keepalived加入监控脚本的配置
master
[root@master ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id lb01
}
vrrp_script haproxy_check { #添加这块
script "/scripts/check_haproxy.sh"
interval 1
weight -20
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.118.250
}
track_script { #添加这块
haproxy_check
}
notify_master "/scripts/notify.sh master 192.168.118.250"
}
virtual_server 192.168.118.250 80 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 50
protocol TCP
real_server 192.168.118.129 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.118.128 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
#重启服务
[root@master ~]# systemctl restart keepalived.service
backup
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 ~]# vim /etc/keepalived/keepalived.conf
onfiguration 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 123456
}
virtual_ipaddress {
192.168.118.250
}
notify_master "/scripts/notify.sh master 192.168.118.250" #只需添加此行
# notify_backup "/scripts/notify.sh backup 192.168.118.250"
}
virtual_server 192.168.118.250 80 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 50
protocol TCP
real_server 192.168.118.129 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.118.128 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
#重启服务
[root@backup ~]# systemctl restart keepalived.service
测试
模拟haproxy服务故障
master
[root@master ~]# curl 192.168.118.250
web1
[root@master ~]# curl 192.168.118.250
web2
[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:b5:9a:13 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.129/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1404sec preferred_lft 1404sec
inet 192.168.118.250/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feb5:9a13/64 scope link noprefixroute
valid_lft forever preferred_lft forever
[root@master ~]# systemctl stop haproxy.service
[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:b5:9a:13 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.129/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1322sec preferred_lft 1322sec
inet6 fe80::20c:29ff:feb5:9a13/64 scope link noprefixroute
valid_lft forever preferred_lft forever
backup获得vip
[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:29:16:02:99 brd ff:ff:ff:ff:ff:ff
inet 192.168.118.128/24 brd 192.168.118.255 scope global dynamic noprefixroute ens33
valid_lft 1328sec preferred_lft 1328sec
inet 192.168.118.250/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe16:299/64 scope link noprefixroute
valid_lft forever preferred_lft forever
[root@backup ~]# curl 192.168.118.250
web1
[root@backup ~]# curl 192.168.118.250
web2
[root@backup ~]# curl 192.168.118.250
web1
[root@backup ~]# curl 192.168.118.250
web2
