Nginx High availability

Why a high availability configuration is needed

Single Nginx Load balance the whole system , If nginx Hang up , Then the whole system will crash , At this point, we need to make sure we're on time 1 individual Nginx Hang up , The whole system is also available .

Now we need to implement Nginx High availability ,nginx High availability needs to be matched with keepalived Together .

preparation

1. Two nginx service

The deployment of two Linux node ,ip Respectively 192.168.12.120 and 198.168.12.121, To start, respectively, nginx

2. Two keepalived service

1).yum Command to install keepalived

yum install -y keepalived

2) After installation , stay etc It generates a directory keepalived, Documents keepalived.conf

3. Complete highly available configuration

modify /etc/keepalived/keepalivec.conf The configuration file

global_defs {

notification_email {

acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 192.168.17.129
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {

script "/usr/local/src/nginx_check.sh"
interval 2 #（ Detects the interval between script execution ）
weight 2
}
vrrp_instance VI_1 {

state BACKUP
# On the backup server MASTER Change it to BACKUP
interface ens33 // network card
virtual_router_id 51
# Lord 、 Standby virtual_router_id It has to be the same 
priority 90
# Lord 、 The standby machine takes different priorities , The main engine is worth a lot , The value of the backup machine is small 
advert_int 1
authentication {

auth_type PASS
auth_pass 1111
}
virtual_ipaddress {

192.168.12.150 // VRRP H Virtual address
}
}

stay /usr/local/src Add detection script

#!/bin/bash
A=`ps -C nginx –no-header |wc -l`
if [ $A -eq 0 ];then
/usr/local/nginx/sbin/nginx
sleep 2
if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
killall keepalived
fi
fi

Put two servers on nginx and keepalived start-up
start-up nginx：./nginx
start-up keepalived：systemctl start keepalived.service

4. Final test

Enter in the address bar 192.168.12.150:8088

Successful visit

From the node ,

take master Corresponding nginx and keepalived Stop

The service is still available .

Indicates that the configuration is in effect .