喜歡搞Nginx，這兩天研究了一下Nginx的負載配置
Nginx平臺搭建：Nginx+mysql+php-fpm搭建高性能Nginx平臺
單Nginx負載均衡：Nginx 負載均衡 配置全過程
熟悉上面的配置之後，今天我再來搞Nginx + Keepalived 的配置，具體拓撲如下：
兩臺前端Nginx，任意一臺掛了另一臺會接管巖機Nginx的虛擬Ip，前面還可以做一個DNS輪詢，沒在線上環境跑過，不知性能如何勒！
一、安裝Keepalived
ln -s /usr/src/kernels/2.6.18-194.el5-i686/ /usr/src/linux
tar zxvf keepalived-1.1.15.tar.gz
cd keepalived-1.1.15
./configure --prefix=/usr/local/keepalived
make
make install
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/ #主配置文件
cp -v /usr/local/keepalived/sbin/keepalived /usr/sbin/
service keepalived start|stop #啓動、停止服務
二、配置Keepalived
/etc/keepalived/keepalived.conf
! 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_nginx {
script "/usr/local/keepalived/check_http.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51 #同一個vrrp_instance，這個ID要相同
priority 100 #同一個vrrp_instance，這個值master要大於backup
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
track_script {
chk_nginx
}
virtual_ipaddress {
192.168.93.144 #定義vip，也就是對外IP，可以寫多個（換行）
}
}
vrrp_instance VI_2 {
state BACKUP
interface eth0
virtual_router_id 52
priority 50
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.93.145
}
}
global_defs 是全局配置，定義郵件報警，我無視它了。
vrrp_script 定義一個監控腳本，作用：發現Nginx掛了，馬上關掉keepalived
vrrp_instance 定義一個虛擬IP，對外服務的，其中還有個track_script ，這個就是調用剛纔定義的監控腳本
另外一臺前端Nginx的Keepalived配置如下：
! 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_nginx {
script "/usr/local/keepalived/check_http.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 50
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.93.144
}
}
vrrp_instance VI_2 {
state MASTER
interface eth0
virtual_router_id 52
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
track_script {
chk_nginx
}
virtual_ipaddress {
192.168.93.145
}
}
另外監控腳本check_http.sh可以自己發揮，原則就是發現Nginx掛了就殺掉keepalived就行，寫法多種
pid=`ps -C nginx --no-header | wc -l`
if [ $pid -eq 0 ]
then
/usr/local/nginx/sbin/nginx
sleep 5
newpid=`ps -C nginx --no-header | wc -l`
if [ $newpid -eq 0 ]
then
killall keepalived
fi
fi
Nginx的配置就不多說
啓動服務
/usr/local/nginx/sbin/nginx
service keepalived start
ps -aef | grep keepalived
root 28742 3288 0 03:21 pts/1 00:00:00 grep keepalived
root 31674 1 0 Oct31 ? 00:00:00 keepalived -D
root 31676 31674 0 Oct31 ? 00:00:00 keepalived -D
root 31677 31674 0 Oct31 ? 00:00:02 keepalived -D
三、測試
主Nginx
ip add
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:0c:29:e0:a3:bf brd ff:ff:ff:ff:ff:ff
inet 192.168.93.137/24 brd 192.168.93.255 scope global eth0
inet 192.168.93.144/32 scope global eth0
inet6 fe80::20c:29ff:fee0:a3bf/64 scope link
valid_lft forever preferred_lft forever
備Nginx
ip add
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:0c:29:ee:a6:22 brd ff:ff:ff:ff:ff:ff
inet 192.168.93.138/24 brd 192.168.93.255 scope global eth0
inet 192.168.93.145/32 scope global eth0
inet6 fe80::20c:29ff:feee:a622/64 scope link
valid_lft forever preferred_lft foreve
我把主Nginx服務停掉之後：
主Nginx
ip add
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:0c:29:e0:a3:bf brd ff:ff:ff:ff:ff:ff
inet 192.168.93.137/24 brd 192.168.93.255 scope global eth0
inet6 fe80::20c:29ff:fee0:a3bf/64 scope link
valid_lft forever preferred_lft forever
備Nginx
ip add
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:0c:29:ee:a6:22 brd ff:ff:ff:ff:ff:ff
inet 192.168.93.138/24 brd 192.168.93.255 scope global eth0
inet 192.168.93.145/32 scope global eth0
inet 192.168.93.144/32 scope global eth0
inet6 fe80::20c:29ff:feee:a622/64 scope link
valid_lft forever preferred_lft forever
備機已經接管了主的ip，然後再把主機的服務恢復：
主Nginx
ip add
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:0c:29:e0:a3:bf brd ff:ff:ff:ff:ff:ff
inet 192.168.93.137/24 brd 192.168.93.255 scope global eth0
inet 192.168.93.144/32 scope global eth0
inet6 fe80::20c:29ff:fee0:a3bf/64 scope link
valid_lft forever preferred_lft forever
備Nginx
ip add
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:0c:29:ee:a6:22 brd ff:ff:ff:ff:ff:ff
inet 192.168.93.138/24 brd 192.168.93.255 scope global eth0
inet 192.168.93.145/32 scope global eth0
inet6 fe80::20c:29ff:feee:a622/64 scope link
valid_lft forever preferred_lft forever
配置完成！