RHEL6 搭建LVS/NAT 負載均衡集群 案例
實驗拓撲圖:
操作流程:
Director Server : 192.168.4.50 pc50
安裝並啟用ipvsadm
創建虛擬服務器
向虛擬服務器上加入節點
Real Server : 192.168.4.51 pc51 192.168.4.52 pc52
配置WEB 服務器
Clinet : 192.168.2.253 pc253
連接虛擬服務器測試
具體步驟:
環境準備:
配置yum源
# service iptables stop //關閉防火墻
# chkconfig iptables off //關閉開機自啟
# setenforce 0 //設置SELinux 為寬松模式
網站服務器 pc51 / pc52 :
# yum -y install httpd
[root@pc51 ~]# echo '192.168.4.51' > /var/www/html/test.html
[root@pc52 ~]# echo "192.168.4.52" > /var/www/html/test.html
# service httpd start
# chkconfig httpd on
# yum -y install elinks
[root@pc51 ~]# elinks --dump http://localhost/test.html
192.168.4.51
[root@pc52 ~]# elinks --dump http://localhost/test.html
192.168.4.52
配置分發器 pc50:
# mount /dev/cdrom /mnt/
//安裝 ipvsadm rpm 包在光盤掛載文件下的LoadBalancer目錄下
#cd /mnt/LoadBalancer/
#yum -y install ipvsadm-1.26-4.el6.x86_64.rpm
//開啟內核的路由轉發功能
# sed -i '7s/0/1/' /etc/sysctl.conf
# sed -n '7p' /etc/sysctl.conf
net.ipv4.ip_forward = 1
網站服務器 pc51 / pc52 :
指定網關地址 192.168.4.50
# route -n//查看路由
# route add default gw 192.168.4.50//臨時配置網關 網卡重啟後生效
//永久配置網關
# vim /etc/sysconfig/network-scripts/ifcfg-eth0
# sed -n '7p' /etc/sysconfig/network-scripts/ifcfg-eth0
GATEWAY=192.168.4.50
# ifdown eth0 ; ifup eth0 //重新加載網卡
客戶端 192.168.2.253 配置
指定網關地址 192.168.2.50 :
# vim /etc/sysconfig/network-scripts/ifcfg-eth1
# sed -n '7p' /etc/sysconfig/network-scripts/ifcfg-eth1
GATEWAY=192.168.2.50
# ifdown eth1 ; ifup eth1
# ping -c 2 192.168.4.51
PING 192.168.4.51 (192.168.4.51) 56(84) bytes of data.
64 bytes from 192.168.4.51: icmp_seq=1 ttl=63 time=0.322 ms
64 bytes from 192.168.4.51: icmp_seq=2 ttl=63 time=0.503 ms
--- 192.168.4.51 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 0.322/0.412/0.503/0.092 ms
# yum -y install elinks
配置分發器 pc50 :
# yum -y install ipvsadm-1.26-4.el6.x86_64.rpm
# rpm -q ipvsadm
ipvsadm-1.26-4.el6.x86_64
添加虛擬服務
# ipvsadm -L //查看 IPVS
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
# ipvsadm -A -t 192.168.2.50:80 -s rr//添加虛擬服務 調度算法為Round Robin
# ipvsadm -L
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.2.50:http rr
# ipvsadm -Ln //- n 數字顯示
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.2.50:80 rr
//向虛擬服務器中加入節點
# ipvsadm -a -t 192.168.2.50:80 -r 192.168.4.51:80 -m
# ipvsadm -a -t 192.168.2.50:80 -r 192.168.4.52:80 -m
# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.2.50:80 rr
-> 192.168.4.51:80 Masq 1 0 0
-> 192.168.4.52:80 Masq 1 0 0
# /etc/init.d/ipvsadm save//使配置永久生效
ipvsadm: Saving IPVS table to /etc/sysconfig/ipvsadm: [確定]
# cat /etc/sysconfig/ipvsadm
-A -t 192.168.2.50:80 -s rr
-a -t 192.168.2.50:80 -r 192.168.4.51:80 -m -w 1
-a -t 192.168.2.50:80 -r 192.168.4.52:80 -m -w 1
客戶端測試
# elinks --dump http://192.168.2.50/test.html
192.168.4.51
# elinks --dump http://192.168.2.50/test.html
192.168.4.52
//客戶端 輪詢到不同的後端真實服務器
[root@pc50 ~]# ipvsadm -Ln --stats
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Conns InPkts OutPkts InBytes OutBytes
-> RemoteAddress:Port
TCP 192.168.2.50:80 2 10 10 846 1098
-> 192.168.4.51:80 1 5 5 423 549
-> 192.168.4.52:80 1 5 5 423 549
模擬pc51 web服務故障:
[root@pc51 ~]# service httpd stop
[root@pc50 ~]# ipvsadm -Z
//客戶端測試
# elinks --dump http://192.168.2.50/test.html
192.168.4.52
# elinks --dump http://192.168.2.50/test.html
192.168.4.52
[root@pc50 ~]# ipvsadm -Ln --stats
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Conns InPkts OutPkts InBytes OutBytes
-> RemoteAddress:Port
TCP 192.168.2.50:80 3 11 11 906 1138
-> 192.168.4.51:80 1 1 1 60 40
-> 192.168.4.52:80 2 10 10 846 1098
會發現 LVS/NAT 單點故障時 並不能健康性檢查
可以 編寫一個腳本 監測兩臺Real Server 的服務 是否正常 如果監測到故障 將對應的服務在調度服務器 停掉
使用周期性計劃任務 定時運行監測腳本 到達 健康檢查的目的
RHEL6 搭建LVS/NAT 負載均衡集群 案例