Keepalived+Lvs高可用负载服务器

 Keepalived+LVS服务器

3.1 问题

使用Keepalived为LVS调度器提供高可用功能，防止调度器单点故障，为用户提供Web服务：

• 路由器对外公网IP地址为202.114.106.20
• 路由器内网IP地址为192.168.0.254
• 路由是需要设置SNAT及DNAT功能
• LVS1调度器真实IP地址为192.168.0.10
• LVS2调度器真实IP地址为192.168.0.20
• 服务器VIP地址设置为192.168.0.253
• 真实Web服务器地址分别为192.168.0.1、192.168.0.2
• 使用加权轮询调度算法，真实服务器权重与其IP地址末尾数一致

3.2 方案

使用5台虚拟机，1台作为Linux路由器、2台作为LVS调度器、2台作为Real Server、物理机作为客户端，拓扑结构如图-2所示。

图-3

3.3 步骤

实现此案例需要按照如下步骤进行。

步骤一：配置网络环境

1）设置Web服务器网络参数

[root@web1 ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.1
NETMASK=255.255.255.0
GATEWAY=192.168.0.254
DNS1=202.106.0.20

[root@web1 ~]# vim /etc/sysconfig/network-scripts/ifcfg-lo:0
DEVICE=lo:0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.253
NETMASK=255.255.255.255

[root@web1 ~]# vim /etc/sysctl.conf
.. ..
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_announce = 2
[root@web1 ~]# sysctl -p
[root@web1 ~]# service NetworkManager stop
[root@web1 ~]# chkconfig NetworkManager off
[root@web1 ~]# service network restart
[root@web1 ~]# iptables -F;service iptables save
##################
[root@web2 ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.2
NETMASK=255.255.255.0
GATEWAY=192.168.0.254
DNS1=202.106.0.20

[root@web2 ~]# vim /etc/sysconfig/network-scripts/ifcfg-lo:0
DEVICE=lo:0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.253
NETMASK=255.255.255.255

[root@web2 ~]# vim /etc/sysctl.conf
.. ..
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_announce = 2
[root@web2 ~]# sysctl -p
[root@web2 ~]# service NetworkManager stop
[root@web2 ~]# chkconfig NetworkManager off
[root@web2 ~]# service network restart
[root@web2 ~]# iptables -F;service iptables save

 

2）自定义Web页面

 

1. [root@web1 ~]# echo “192.168.0.1” > /var/www/html/index.html
2. [root@web2 ~]# echo “192.168.0.2” > /var/www/html/index.html

3）启动Web服务器软件

 

1. [root@web1 ~]# service httpd start;chkconfig httpd on
2. [root@web2 ~]# service httpd start;chkconfig httpd on

4)设置LVS调度器网络参数

 

1. [root@lvs1 ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0
2. DEVICE=eth0
3. ONBOOT=yes
4. BOOTPROTO=static
5. IPADDR=192.168.0.10
6. NETMASK=255.255.255.0
7. GATEWAY=192.168.0.254
8. DNS1=202.106.0.20
9. [root@lvs1 ~]# service NetworkManager stop
10. [root@lvs1 ~]# chkconfig NetworkManager off
11. [root@lvs1 ~]# service network restart
12. [root@lvs1 ~]# iptables -F;service iptables save
13. [root@lvs2 ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0
14. DEVICE=eth0
15. ONBOOT=yes
16. BOOTPROTO=static
17. IPADDR=192.168.0.20
18. NETMASK=255.255.255.0
19. GATEWAY=192.168.0.254
20. DNS1=202.106.0.20
21. [root@lvs2 ~]# service NetworkManager stop
22. [root@lvs2 ~]# chkconfig NetworkManager off
23. [root@lvs2 ~]# service network restart
24. [root@lvs2 ~]# iptables -F;service iptables save

5）设置Linux路由器网络参数

 

1. [root@router ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0
2. DEVICE=eth0
3. ONBOOT=yes
4. BOOTPROTO=static
5. IPADDR=202.114.106.20
6. DNS1=202.106.0.20
7. [root@router ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth1
8. DEVICE=eth0
9. ONBOOT=yes
10. BOOTPROTO=static
11. IPADDR=192.168.0.254
12. NETMASK=255.255.255.0
13. DNS1=202.106.0.20
14. [root@router ~]# service NetworkManager stop
15. [root@router ~]# chkconfig NetworkManager off
16. [root@router ~]# service network restart
17. [root@router ~]# iptables -F;service iptables save

6）设置Linux路由器的SNAT、DNAT功能

 

1. [root@router ~]# sed -i '/ip_forward/s/0/1/' sysctl.conf //开启路由转发
2. [root@router ~]# sysctl -p
3. [root@router ~]# iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -p tcp –j SNAT --to-source 202.114.106.20
4. [root@router ~]# iptables -t nat -A PREROUTING -d 202.114.106.20 -p tcp --dport 80 –j DNAT --to-destination 192.168.0.253:80
5. [root@router ~]# service iptables save

步骤二：调度器安装Keepalived与ipvsadm软件

注意：两台LVS调度器执行相同的操作。

安装软件

 

1. [root@lvs1 ~]# yum install -y gcc kernel-devel openssl-devel popt-devel
2. [root@lvs1 ~]# tar -xzf keepalived-1.2.7.tar.gz
3. [root@lvs1 ~]# cd keepalived-1.2.7
4. [root@lvs1 keepalived-1.2.7]# ./configure --sysconf=/etc
5. [root@lvs1 keepalived-1.2.7]# make && make install
6. [root@lvs1 keepalived-1.2.7]# ln -s /usr/local/sbin/keepalived /sbin/
7. [root@lvs1 keepalived-1.2.7]# chkconfig keepalived on
8. [root@lvs1 Pacages]# rpm –ihv ipvsadm-1.25-10.el6.x86_64.rpm
9. [root@lvs2 ~]# yum install -y gcc kernel-devel openssl-devel popt-devel
10. [root@lvs2 ~]# tar -xzf keepalived-1.2.7.tar.gz
11. [root@lvs2 ~]# cd keepalived-1.2.7
12. [root@lvs2 keepalived-1.2.7]# ./configure --sysconf=/etc
13. [root@lvs2 keepalived-1.2.7]# make && make install
14. [root@lvs2 keepalived-1.2.7]# ln -s /usr/local/sbin/keepalived /sbin/
15. [root@lvs2 keepalived-1.2.7]# chkconfig keepalived on
16. [root@lvs2 Pacages]# rpm –ihv ipvsadm-1.25-10.el6.x86_64.rpm

步骤三：部署Keepalived实现LVS-DR模式调度器的高可用

1）LVS1调度器设置Keepalived，并启动服务

 

1. [root@lvs1 ~]# vim /etc/keepalived/keepalived.conf
2. global_defs {
3. notification_email {
4. admin@tarena.com.cn                //设置报警收件人邮箱
5. }
6. notification_email_from ka@localhost    //设置发件人
7. smtp_server 127.0.0.1                //定义邮件服务器
8. smtp_connect_timeout 30
9. router_id lvs1                        //设置路由ID号
10. }
11. vrrp_instance VI_1 {
12. state MASTER                          //主服务器为MASTER
13. interface eth0                        //定义网络接口
14. virtual_router_id 50                    //主辅VRID号必须一致
15. priority 100                     //服务器优先级
16. advert_int 1
17. authentication {
18. auth_type pass
19. auth_pass forlvs                      //主辅服务器密码必须一致
20. }
21. virtual_ipaddress { 192.168.0.253 }
22. }
23. virtual_server 192.168.0.253 80 {      //设置VIP为192.168.0.253
24. delay_loop 6
25. lb_algo wrr                 //设置LVS调度算法为RR
26. lb_kind DR                          //设置LVS的模式为DR
27. persistence_timeout 1
28. protocol TCP
29. real_server 192.168.0.1 80 {
30. weight 1                  //设置权重为1
31. TCP_CHECK {
32.     connect_timeout 3
33.     nb_get_retry 3
34.     delay_before_retry 3
35. }
36. }
37. real_server 192.168.0.2 80 {
38. weight 2                  //设置权重为2
39. TCP_CHECK {
40.     connect_timeout 3
41.     nb_get_retry 3
42.     delay_before_retry 3
43. }
44. }
45. [root@lvs1 ~]# service keepalived start
46. [root@lvs1 ~]# ipvsadm -Ln

2）LVS2调度器设置Keepalived

 

1. [root@lvs1 ~]# vim /etc/keepalived/keepalived.conf
2. global_defs {
3. notification_email {
4. admin@tarena.com.cn                //设置报警收件人邮箱
5. }
6. notification_email_from ka@localhost    //设置发件人
7. smtp_server 127.0.0.1                //定义邮件服务器
8. smtp_connect_timeout 30
9. router_id lvs2                        //设置路由ID号
10. }
11. vrrp_instance VI_1 {
12. state SLAVE                          //从服务器为SLAVE
13. interface eth0                        //定义网络接口
14. virtual_router_id 50                    //主辅VRID号必须一致
15. priority 50                     //服务器优先级
16. advert_int 1
17. authentication {
18. auth_type pass
19. auth_pass forlvs                      //主辅服务器密码必须一致
20. }
21. virtual_ipaddress { 192.168.0.253 }
22. }
23. virtual_server 192.168.0.253 80 {      //设置VIP为192.168.0.253
24. delay_loop 6
25. lb_algo wrr                 //设置LVS调度算法为RR
26. lb_kind DR                          //设置LVS的模式为DR
27. persistence_timeout 1
28. protocol TCP
29. real_server 192.168.0.1 80 {
30. weight 1                  //设置权重为1
31. TCP_CHECK {
32.     connect_timeout 3
33.     nb_get_retry 3
34.     delay_before_retry 3
35. }
36. }
37. real_server 192.168.0.2 80 {
38. weight 2                  //设置权重为2
39. TCP_CHECK {
40.     connect_timeout 3
41.     nb_get_retry 3
42.     delay_before_retry 3
43. }
44. }
45. [root@lvs2 ~]# service keepalived start
46. [root@lvs2 ~]# ipvsadm -Ln

步骤四：客户端测试

客户端使用curl命令反复连接http://202.114.106.20，查看访问的页面是否会轮询到不同的后端真实服务器。

来源：https://www.cnblogs.com/linux985/p/11799934.html