Nginx + Keepalived 負載均衡

喜歡搞Nginx，這兩天研究了一下Nginx的負載配置

Nginx平台搭建：Nginx+mysql+php-fpm搭建高性能Nginx平台

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：

兩台前端Nginx，任意一台挂了另一台會接管岩機Nginx的虛拟Ip，前面還可以做一個DNS輪詢，沒線上上環境跑過，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/   #主配置檔案

cp -v /usr/local/keepalived/sbin/keepalived /usr/sbin/

service keepalived start|stop           #啟動、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要大于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

    virtual_router_id 52

    priority 50

        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挂了，馬上關掉keepalived

vrrp_instance 定義一個虛拟IP，對外服務的，其中還有個track_script ，這個就是調用剛才定義的監控腳本

另外一台前端Nginx的Keepalived配置如下：

 ! Configuration File for keepalived

    virtual_router_id 51

        192.168.93.144

    priority 100

另外監控腳本check_http.sh可以自己發揮，原則就是發現Nginx挂了就殺掉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

啟動服務

/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

    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：

備機已經接管了主的ip，然後再把主機的服務恢複：