环境:
[root@db02 ~]# uname -a
Linux db02 2.6.32-696.el6.x86_64 #1 SMP Tue Mar 21 19:29:05 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
[root@db02 ~]# cat /etc/redhat-release
CentOS release 6.9 (Final)
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
Keepalived软件的官方站点是 http://www.keepalived.org
1、Keepalived高可用对之间是通过VRRP通信的
1) 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。
2) VRRP是通过一种竞选协议机制来将路由任务交给某台VRRP路由器的。
3) 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。
4) 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资源。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。
5) 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。
2、Keepalived 服务的工作原理
Keepalived高可用对之间是通过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服务对之间,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,此时备不会抢占主,当主不可用时,即备监听不到主发送的广播包时,就会启动相关股务接管资源,保证业务的连续性。接管速度最快可以小于1秒。
需要的服务器介绍:需要三台web服务器,两台lb(负载)服务器
web服务器:(每台web有两个站点bbs和www)
web01:172.16.1.8(内网)10.0.0.8(外网)
web02:172.16.1.7(内网)10.0.0.7(外网)
web03:172.16.1.9(内网)10.0.0.9(外网)
web集群服务器配置文件环境统一(web01 web02 web03 配置均一致)
cat www.conf
server {
listen 80;
server_name www.zxpo.com;
location / {
root html/www;
index index.html index.htm;
}
}
cat bbs.conf
server {
listen 80;
server_name bbs.zxpo.com;
location / {
root html/bbs;
index index.html index.htm;
}
}
同步三台web服务器配置:
scp -rp {www.conf,bbs.conf} 172.16.1.7:/application/nginx/conf/extra/
scp -rp {www.conf,bbs.conf} 172.16.1.9:/application/nginx/conf/extra/
web服务主配置文件环境统一:
[root@web01 extra]# cat ../nginx.conf
worker_processes 1;
events {
worker_connections 1024;
}
http {
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 logs/access.log main;
include mime.types;
default_type application/octet-stream;
sendfile on;
keepalive_timeout 65;
include extra/www.conf;
include extra/bbs.conf;
}
scp -rp ../nginx.conf 172.16.1.9:/application/nginx/conf/
scp -rp ../nginx.conf 172.16.1.7:/application/nginx/conf/
web01测试环境准备:
[root@web01 www]# for name in www bbs;do echo $name `hostname` >/application/nginx/html/$name/nana.html;done
[root@web01 www]# for name in www bbs;do cat /application/nginx/html/$name/nana.html;done
www web01
bbs web01
web02测试环境准备:
[root@web02 conf]# for name in www bbs;do echo $name `hostname` >/application/nginx/html/$name/nana.html;done
[root@web02 conf]# for name in www bbs;do cat /application/nginx/html/$name/nana.html;done
www web02
bbs web02
web03测试环境准备:
[root@web03 conf]# for name in www bbs;do echo $name `hostname` >/application/nginx/html/$name/nana.html;done
[root@web03 conf]# for name in www bbs;do cat /application/nginx/html/$name/nana.html;done
www web03
bbs web03
web环境测试结果:(在lb负载均衡服务器上面进行)
[root@web01 www]# curl -H host:www.zxpo.com 10.0.0.8/nana.html
www web01
[root@web01 www]# curl -H host:bbs.zxpo.com 10.0.0.8/nana.html
bbs web01
[root@web01 www]# curl -H host:www.zxpo.com 10.0.0.7/nana.html
www web02
[root@web01 www]# curl -H host:bbs.zxpo.com 10.0.0.7/nana.html
bbs web02
[root@web01 www]# curl -H host:www.zxpo.com 10.0.0.9/nana.html
www web03
[root@web01 www]# curl -H host:bbs.zxpo.com 10.0.0.9/nana.html
bbs web03
nginx反向代理负载均衡集群服务器配置文件环境统一
[root@lb01 conf]# cat nginx.conf
####lb01和lb02 nginx.conf
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
sendfile on;
keepalive_timeout 65;
upstream server_pools {
server 10.0.0.7:80;
server 10.0.0.8:80;
server 10.0.0.9:80;
}
server {
listen 80;
server_name www.zxpo.com;
location / {
proxy_pass http://server_pools;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $remote_addr;
}
}
server {
listen 80;
server_name bbs.zxpo.com;
location / {
proxy_pass http://server_pools;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $remote_addr;
}
}
}
yum install -y keepalived
启动lb01 lb02的keepalived服务
/etc/init.d/keepalived start
[root@lb01 conf]# 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
}
}
配置文件组成部分
! Configuration File for keepalived
global_defs { --- 全局配置标题
notification_email { --- 定义管理员邮箱信息
110@qq.com
110@qq.com
}
notification_email_from zxpo@163.com --- 定义利用什么邮箱发送邮件
smtp_server smtp.163.com --- 定义邮件服务器信息
smtp_connect_timeout 30 --- 定义邮件发送超时时间
router_id a01 --- (重点参数)局域网keepalived主机身份标识信息每一个keepalived主机身份标识信息唯一
}
vrrp_instance VI_1 { --- vrrp协议相关配置(vip地址设置)
state MASTER --- keepalived角色描述(状态)信息,可以配置参数(MASTER BACKUP)
interface eth0 --- 表示将生成虚IP地址,设置在指定的网卡上
virtual_router_id 51 --- 表示keepalived家族标识信息
priority 100 --- keepalived服务竞选主备服务器优先级设置(越大越优先)
advert_int 1 --- 主服务组播包发送间隔时间
authentication { --- 主备主机之间通讯认证机制,
auth_type PASS --- 采用明文认证机制
auth_pass 1111 --- 编写明文密码
}
virtual_ipaddress { --- 设置虚拟IP地址信息
10.0.0.3
}
}
global_defs {
router_id LVS_01
}
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
}
}
global_defs {
router_id LVS_02
}
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
}
}
说明:主备服务器配置文件区别 router_id 不同 state BACKUP 不同 priority 不同
更改nginx反向代理,只监听虚拟ip
[root@lb01 keepalived]# cat /application/nginx/conf/nginx.conf
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
sendfile on;
keepalive_timeout 65;
upstream server_pools {
server 10.0.0.7:80;
server 10.0.0.8:80;
server 10.0.0.9:80;
}
server {
listen 10.0.0.3:80;
server_name www.zxpo.com;
location / {
proxy_pass http://server_pools;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $remote_addr;
}
}
server {
listen 10.0.0.3:80;
server_name bbs.zxpo.com;
location / {
proxy_pass http://server_pools;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $remote_addr;
}
}
server {
listen 10.0.0.3:80;
server_name blog.zxpo.com;
location / {
proxy_pass http://server_pools;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $remote_addr;
}
}
}
做到这其实可以启动nginx了,但是会失败,因为需要优化内核
[root@lb02 ~]# cat /proc/sys/net/ipv4/ip_nonlocal_bind
0
这个文件默认值为一,如果为1,就代表本地就算没有这个ip也可以监听
echo "net.ipv4.ip_nonlocal_bind=1" >>/etc/sysctl.conf
sysctl -p
最后一行为 net.ipv4.ip_nonlocal_bind = 1 就可以了。
[root@lb02 ~]# netstat -lntup |grep nginx
tcp 0 0 10.0.0.3:80 0.0.0.0:*
LISTEN 11279/nginx