Keepalived+LVS | Keepalived+Nginx

keepalived+lvs

---

準備4臺虛擬機分別爲server1,server2,server3,server4(server1爲主機，4爲備機)

安裝

• 安裝包
  keepalived-1.2.5.tar.gz

tar zxf keepalived-1.2.5.tar.gz

• 依賴性解決

yum install -y ipvsadm kernel-devel openssl-devel popt-devel libnl-devel gcc make

• 編譯安裝
  ./configure –prefix=/usr/local/keepalived ##keepalived路徑

• 編譯結果：
  Keepalived configuration
  —————————————————
  Keepalived version : 1.2.5
  Compiler : gcc
  Compiler flags : -g -O2
  Extra Lib : -lpopt -lssl -lcrypto -lnl
  Use IPVS Framework : Yes
  IPVS sync daemon support : Yes
  IPVS use libnl : No
  Use VRRP Framework : Yes
  Use VRRP VMAC : Yes
  SNMP support : No
  Use Debug flags : No

make && make install

keepalived + lvs

配置keepalived

server1與server4同:

ln -s /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/  
ln -s /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
ln -s /usr/local/keepalived/etc/keepalived /etc/
ln -s /usr/local/keepalived/sbin/keepalived /usr/sbin

keepalived主配置文件：

vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   notification_email {         
     root@localhost             ##接收警報的email地址，可添加多個
   }
   notification_email_from keepalived@server1   ##郵件的發送地址
   smtp_server 127.0.0.1            ##設置smtp server地址爲本機
   smtp_connect_timeout 30          ##連接smtp服務器超時時間
   router_id LVS_DEVEL              ##loadbalancer的標識，用於email警報
}

vrrp_instance VI_1 {
    state MASTER        ##設定本機爲主，server4爲BACKUP，此狀態由priority的值決定，priority值大則爲MASTER
    interface eth0      ##HA檢測網絡接口
    virtual_router_id 87    ##vrid,主備機的vrid必須相同，取值0-255
    priority 100        ##優先級
    advert_int 1        ##主備之間的通告間隔秒數
    authentication {        ##主備切換時的認證
        auth_type PASS      ##驗證類型，主要有PASS和AH兩種
        auth_pass 1111      ##設置驗證密碼，在一個vrrp_instance下，MASTER與BACKUP必須使用相同的密碼才能正常通信
    }

virtual_ipaddress {     ##設置虛擬IP地址，可以設置多個虛擬IP地址，每行一個
        172.25.36.100
    }
}

virtual_server 172.25.36.100 80 {   ##定義虛擬服務器
    delay_loop 6            ##每隔6秒檢查realserver狀態
    lb_algo rr              ##lvs調度算法爲輪叫rr
    lb_kind DR              ##lvs使用DR模式
    nat_mask 255.255.255.0
    #persistence_timeout 50     ##連接後端服務器，50S內不會負載均衡
    protocol TCP        ##指定轉發協議類型，有tcp和udp兩種

    real_server 172.25.36.2 80 {    ##配置服務節點
        weight 1            ##服務節點權值
        TCP_CHECK {         ##realserver的狀態檢測部分
            connect_timeout 3       ##3秒無響應超時
            nb_get_retry 3      ##重試次數爲3次
            delay_before_retry 3    ##重試間隔
        }

    real_server 172.25.36.3 80 {    ##配置服務節點
        weight 1            ##服務節點權值
        TCP_CHECK {         ##realserver的狀態檢測部分
            connect_timeout 3       ##3秒無響應超時
            nb_get_retry 3      ##重試次數爲3次
            delay_before_retry 3
}    
/etc/init.d/keepalived start

scp /etc/keepalived/keepalived.conf root@172.25.36.4:/etc/keepalived/

server4:

vim /etc/keepalived/keepalived.conf     ##只修改這兩處
vrrp_instance VI_1 {
    state BACKUP
    priority 50
}

/etc/init.d/keepalived start

server2,server3:

ip addr add 172.25.36.100/32 dev eth0

/etc/init.d/httpd start

測試：

1.真機curl 172.25.36.100

server1的mac地址爲09:9f

2.server1:

/etc/init.d/keepalived stop

真機:curl 172.25.36.100

server4的mac地址爲46:f9

3.server4:
/etc/init.d/keepalived stop
server1:
/etc/init.d/keepalived start

curl 172.25.36.100(server1接管)

keepalived爲單線程，其下由兩個子進程

第一個子進程：vrrp協議，實現高可用
第二個子進程：健康檢查，維護LVS的策略

keepalived+LVS+vsftp

server2,server3:

yum install -y arptables_jf

arptables -A IN -d 172.25.36.100 -j DROP    ##將RS接受到的172.25.36.100包丟棄
arptables -A OUT -s 172.25.36.100 -j mangle --mangle-ip-s 172.25.36.3   ##將源時172.25.36.100的請求發送給172.25.36.3

/etc/init.d/arptables_jf save
/etc/init.d/arptables_jf start

查看arptables:
arptables -L

server1,server4中keepalived.conf同時添加如下:

vim /etc/keepalived/keepalived.conf
virtual_server 172.25.36.100 21 {   ##vsftpd端口爲21端口
    delay_loop 6
    lb_algo rr
    lb_kind DR
    nat_mask 255.255.255.0
    persistence_timeout 50     ##連接後端服務器，50S內不會負載均衡
    protocol TCP

    real_server 172.25.36.2 21 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }

    real_server 172.25.36.3 21 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
    }
    }
}

/etc/init.d/keepalived restart

查看配置是否生效：
ipvsadm -l

server2,server3中：

yum install vsftpd -y
/etc/init.d/vsftpd start 

mkdir /var/ftp/server2(server3)     ##方便測試看出效果

測試:

1.真機：lftp 172.25.36.100 -> ls

2.server1:
/etc/init.d/keepalived stop

真機：lftp 172.25.36.100(server4會接管keepalived)

3.server3:
/etc/init.d/vsftpd stop

真機：lftp 172.25.36.100

keepalived + nginx

---

配置nginx:
server1(nginx所在主機):

http {
        upstream westos {       ##添加westos負載均衡組
        server 172.25.36.2:80;
        server 172.25.36.3:80;
        }

server {
        listen 80;
        server_name www.westos.org; ##添加訪問域名

        location / {
                proxy_pass http://westos;   ##訪問westos負載均衡組
        }
    }

nginx -s reload

scp -r nginx/ server4:/usr/local/

server4:

/usr/local/nginx/sbin/nginx -t      ##檢查nginx配置文件是否出錯

/usr/local/nginx/sbin/nginx     ##運行nginx

server2,server3:

/etc/init.d/httpd start         ##運行httpd(port 80)

在測試主機上將解析加入：
vim /etc/hosts
172.25.36.100 www.westos.org

測試：
主機web：www.westos.org(有輪詢)

輪詢

配置keepalived:

keepalived服務(server1,server4):

cd /opt

vim nginx_check.sh
#!/bin/bash

curl http://127.0.0.1/index.html -o /dev/null -s || /usr/local/lnmp/nginx/sbin/nginx            ##檢測nginx是否運行，若沒有運行則運行nginx

if [ $? -ne 0 ];then
/etc/init.d/keepalived stop &> /dev/null    ##若不能運行nginx則關閉本機keepalived由備機server4接管
fi

vim /etc/keepalived/keepalived.conf
vrrp_script nginx_check {
        script /opt/nginx_check.sh  ##腳本位置
        interval 2          ##檢查間隔兩秒

global_defs {
   notification_email {
     root@localhost
   }
   notification_email_from keepalived@server1
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 87
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        172.25.36.100/24
    }

track_script {
        nginx_check     ##腳本資源爲nginx_check
}

測試：
1.server1:
/etc/init.d/keepalived start
nginx -s stop ##停止運行nginx

真機web:
www.westos.org ##可以正常訪問，因爲keepalived中腳本每兩秒檢測，檢測到nginx關閉而開啓了nginx

2.server1:
mv /usr/local/lnmp/nginx/ /mnt/
/etc/init.d/keepalived start

真機web:
www.westos.org ##可以正常訪問，因爲keepalived在server1中被停止運行後由備機server4接管