keepalived双主模式
减轻负载均衡压力（两者互为主备）
第一个里程碑
- lb01配置文件
[root@lb01 ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id lb01
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 150
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.3/24 dev eth0 label eth0:1
}
}
vrrp_instance VI_2 {
state BACKUP
interface eth0
virtual_router_id 52
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.4/24 dev eth0 label eth0:2
}
}
- lb02配置文件
[root@bl02 ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id lb01
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.3/24 dev eth0 label eth0:1
}
}
vrrp_instance VI_2 {
state MASTER
interface eth0
virtual_router_id 52
priority 150
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.4/24 dev eth0 label eth0:2
}
}
image.png
第二个 里程碑
- 配置完成测试
[root@bl02 ~]# ip a |egrep "0.3|0.4"
inet 10.0.0.4/24 scope global secondary eth0:2
[root@lb01 ~]# ip a |egrep "0.3|0.4"
inet 10.0.0.3/24 scope global secondary eth0:1
[root@lb01 ~]#
[root@lb01 ~]# curl 10.0.0.3
web01 www.oldboy.com
[root@lb01 ~]# curl 10.0.0.3
web02 www.oldboy.com
[root@lb01 ~]# curl 10.0.0.4
web01 www.oldboy.com
[root@lb01 ~]# curl 10.0.0.4
web02 www.oldboy.com
[root@lb01 ~]#
- 关闭lb01进行测试
[root@lb01 ~]# systemctl stop keepalived.service
inet 10.0.0.4/24 scope global secondary eth0:2
inet 10.0.0.3/24 scope global secondary eth0:1
[root@bl02 ~]#
keepalived监控nginx
第一个里程碑
- 写一个脚本监控nginx状态 如果nginx挂掉，keepalived也关闭
#!/bin/bash
count=`ps -ef |grep nginx |grep -v |wc -l`
if [ $count -eq 0 ];then
systemctl stop keepalived
fi
第二个里程碑
- 给脚本加上执行权限后写入keepalived的配置文件
[root@lb01 /etc/keepalived]# cat keepalived.bak.script
I! Configuration File for keepalived
global_defs {
router_id lb01
}
vrrp_script kep_ngx {
scrpit "/server/scripts/kep_ngx.sh"
interval 2
weight 1
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 150
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.3/24 dev eth0 label eth0:1
}
track_script {
kep_ngx
}
}
每个域名绑定对应 IP
- 修改内核参数（针对nginx语法错误）
[root@lb01 ~]# cat /etc/sysctl.conf
# sysctl settings are defined through files in
# /usr/lib/sysctl.d/, /run/sysctl.d/, and /etc/sysctl.d/.
#
# Vendors settings live in /usr/lib/sysctl.d/.
# To override a whole file, create a new file with the same in
# /etc/sysctl.d/ and put new settings there. To override
# only specific settings, add a file with a lexically later
# name in /etc/sysctl.d/ and put new settings there.
#
# For more information, see sysctl.conf(5) and sysctl.d(5).
net.ipv4.ip_nonlocal_bind = 1
实际修改
[root@lb01 ~]# cat /proc/sys/net/ipv4/ip_nonlocal_bind
1
- 修改配置文件
[root@lb01 /etc/keepalived]# cat /etc/nginx/nginx.conf
user nginx;
worker_processes 1;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
#tcp_nopush on;
keepalive_timeout 65;
upstream web_pools {
server 10.0.0.7:80 weight=1 max_fails=3 fail_timeout=10s;
server 10.0.0.8:80 weight=1 max_fails=3 fail_timeout=10s;
}
#gzip on;
#include /etc/nginx/conf.d/*.conf;
server {
listen 10.0.0.3:80;
server_name www.oldboy.com;
location / {
proxy_pass http://web_pools;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $remote_addr;
}
}
server {
listen 10.0.0.4:80;
server_name blog.oldboy.com;
location / {
proxy_pass http://web_pools;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $remote_addr;
}
}
}
Keepalived高可用故障
image.png
