nginx+keepalived高可用及双主模式
高可用有2中方式。
1、Nginx+keepalived 主从配置
这种方案，使用一个vip地址，前端使用2台机器，一台做主，一台做备，但同时只有一台机器工作，另一台备份机器在主机器不出现故障的时候，永远处于浪费状态，对于服务器不多的网站，该方案不经济实惠。
2、Nginx+keepalived 双主配置
这种方案，使用两个vip地址，前端使用2台机器，互为主备，同时有两台机器工作，当其中一台机器出现故障，两台机器的请求转移到一台机器负担，非常适合于当前架构环境。
1、Nginx+keepalived 主从配置
1.环境如下
lb-01:192.168.96.130 nginx+keepalived-master
lb-02:192.168.96.131 nginx+keepalived-backup
VIP：192.168.75.135
nginx+tomcat负载均衡集群参照 nginx+tomcat负载均衡集群参照
两台机器都要安装nginx 配置文件相同
upstream myServer{
server 192.168.96.130:8080;
server 192.168.96.131:8080;
}
server {
listen 80;
server_name localhost;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
proxy_pass http://myServer;
}
nginx结合keepalived高可用
为什么使用keepalived呢？使用keepalived就用来做高可用的，提供虚拟VIP分别在2台机子上安装keepalived
# yum install keepalived -y
查看keepalived版本
# keepalived -v
Keepalived v1.2.13 (11/20,2015)
关于2台keepalived配置文件/etc/keepalived
在130master keepalived配置文件内容如下
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {
script "/usr/local/src/check_nginx_pid.sh"
interval 2 #（检测脚本执行的间隔）
weight 2
}
vrrp_instance VI_1 {
state MASTER # 备份服务器上将 MASTER 改为 BACKUP
interface eno16777736 //网卡
virtual_router_id 51 # 主、备机的virtual_router_id必须相同
priority 100 # 主、备机取不同的优先级，主机值较大，备份机值较小
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.96.138 // VRRP H虚拟地址
}
}
在131-backup keepalived配置文件内容如下
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {
script "/usr/local/src/check_nginx_pid.sh"
interval 2 #（检测脚本执行的间隔）
weight 2
}
vrrp_instance VI_1 {
state BACKUP
interface eno16777736
virtual_router_id 51
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.96.138
}
}然后分别启动2台keepalived服务
[root@lb-01 ~]# systemctl start keepalived.service
[root@lb-02 ~]# systemctl start keepalived.service
查看虚拟VIP
130-master机器查看
从上面可以看到虚拟VIP地址192.168.96.138
131-backup机器查看
从上面可以看到没有虚拟VIP地址
测试访问虚拟VIP
打开浏览器访问
此时虚拟VIP可以轮询访问了
模拟故障
把130-master nginx和keepalived停止查看是否还能正常提供服务
[root@lb-01 sbin]# ./nginx -s stop
[root@lb-01 sbin]# systemctl stop keepalived.service
此时虚拟VIP已经不再master上了
客户端打开浏览器访问是否正常访问
130nginx和keepalived挂了也不影响服务
查看131backup机器VIP情况
此时虚拟VIP 已经在131机器上
那么如何实现nginx+keepalived双主模式呢？
1.其实只是需要更改下keepalived配置文件即可，配置文件实例如下
增加新的VIP192.168.96.139,192.168.75.138是130机器上主虚拟VIP，192.168.96.139是131机器上主虚拟VIP130的keepalived配置文件内容如下
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {
script "/usr/local/src/check_nginx_pid.sh"
interval 2 #（检测脚本执行的间隔）
weight 2
}
vrrp_instance VI_1 {
state MASTER
interface eno16777736
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.96.138
}
}
vrrp_instance VI_2 {
state BACKUP
interface eno16777736
virtual_router_id 52
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.96.139
}
}
131 的keepalived配置文件内容如下
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {
script "/usr/local/src/check_nginx_pid.sh"
interval 2 #（检测脚本执行的间隔）
weight 2
}
vrrp_instance VI_1 {
state BACKUP
interface eno16777736
virtual_router_id 51
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.96.138
}
}
vrrp_instance VI_2 {
state MASTER
interface eno16777736
virtual_router_id 52
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.96.139
}
}分别启动2台lb上nginx和keepalived服务
[root@lb-01 sbin]# ./nginx [root@lb-01 sbin]# systemctl start keepalived.service130查看虚拟ip
131查看虚拟ip
客户端测试访问虚拟VIP
访问虚拟VIP:192.168.96.138结果如下
访问虚拟VIP:192.168.96.139结果如下
模拟故障
把130服务停止
查看130虚拟VIP是否存在结果如下
没了
测试访问虚拟VIP**
从上面结果可以看到，即使130机器发生了故障也不影响使用，这样也利用131资源了
此时查看一下131虚拟ip结果情况如下
注：此时虚拟VIP地址都已经在lb-02机器上了