Linux运维之DR模式下的高可用LVS

高可用的作用
高可用是资源池中的某些物理主机出现故障后，故障物理主机上的虚拟机会在资源池内其他正常的物理主机上启动，从而保障资源池安全可靠的持续运行，是服务器虚拟化软件的常见功能。

搭建步骤
本次实验用四个虚拟机,分别为server1,server2,server3,server4,server1作为主调度器,server4作为辅助调度器,当主调度器故障后辅助调度会代替工作。

1. server1:配置yum源

   vim /etc/yum.repos.d/rhel-source.repo

      [rhel-source]
      name=Red Hat Enterprise Linux $releasever - $basearch - Source
      baseurl=http://172.25.61.250/rhel6.5
      enabled=1
      gpgcheck=1
      gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
      
      [LoadBalancer]
      name=LoadBalancer
     baseurl=http://172.25.61.250/rhel6.5/LoadBalancer
     gpgcheck=0
     
     [HighAvailability]
     name=HighAvailability
     baseurl=http://172.25.61.250/rhel6.5/HighAvailability
     gpgcheck=0
   

2. 在主调度器上安装源码包keepalived-2.0.6

解压 :tar zxf keepalived-2.0.6.tar.gz

3. 安装编译所需软件

    yum install -y gcc libnl libnl-devel
    yum install -y openssl-devel
   
    yum install -y libnfnetlink-devel-1.0.0-1.el6.x86_64.rpm
   

4. 进入解压好的目录下,编译,安装

    cd keepalived-2.0.6
    ./configure --prefix=/usr/local/keepalive --with-init=SYSV
    make && make install
   

看到 Use IPVS Framework 为yes就算编译安装完成

5.将主调度器上编译完成的keeplived发给辅助rs一份

	scp /usr/local/keepalived/ server4:/usr/local

	chmod +x  /usr/local/keepalived/etc/rc.d/init.d/keepalived         ##给予可执行权限
	    ln -s /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/ 
	    ln -s /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/       ###制作软链接
	    ln -s /usr/local/keepalived/etc/keepalived/ /etc/
	    ln -s /usr/local/keepalived/sbin/keepalived /sbin/

辅助rs相同的步骤

6. 安装调度器

yum install ipvsadm -y

编写主rs的keepalived主配置文件

vim /etc/keepalived/keepalived.conf

	 1 global_defs {
	 2    notification_email {
	 3      root@localhost
	 4    }
	 5    notification_email_from Alexandre.Cassen@firewall.loc
	 6    smtp_server 127.0.0.1
	 7    smtp_connect_timeout 30
	 8    router_id LVS_DEVEL
	 9    vrrp_skip_check_adv_addr
	 10    #vrrp_strict
	 11    vrrp_garp_interval 0
	 12    vrrp_gna_interval 0
	 13 }
	 14 
	 15 vrrp_instance VI_1 {
	 16     state MASTER
	 17     interface eth0
	 18     virtual_router_id 51
	 19     priority 100
	 20     advert_int 1
	 21     authentication {
	 22         auth_type PASS
	 23         auth_pass 1111
	 24     }
	 25     virtual_ipaddress {
	 26         172.25.61.100
	 27     }
	 28 }
	 29 
	 30 virtual_server 172.25.61.100 80 {
	 31     delay_loop 3
	 32     lb_algo rr
	 33     lb_kind DR
	 34    #persistence_timeout 50
	 35     protocol TCP
	 36 
	 37     real_server 172.25.61.2 80 {
	 38         TCP_CHECK{
	 39         weight 1
	 40             connect_timeout 3
	 41             retry 3
	 42             delay_before_retry 3
	 43         }
	 44     }
	 45 
	 46     real_server 172.25.61.3 80 {
	 47         TCP_CHECK{
	 48         weight 1
	 49             connect_timeout 3
	 50             retry 3
	 51             delay_before_retry 3
	 52         }
	 53     }
	 54 }

备用调度器上配置文件要将MASTER改为BACKUP,priority权重系数改为50

7. server2和server3的apache服务开启

8. server1和server4(即主调度器和辅助调度器)的服务打开

    /etc/init.d/keepalived start
   

9. 测试
   在真机上测试
   发现server2和server3轮循调度

   [root@foundation61 ~]# curl 172.25.61.100
   <h1>LVS server3</h1>
   [root@foundation61 ~]# curl 172.25.61.100
   <h1>LVS server2</h1>
   [root@foundation61 ~]# curl 172.25.61.100
   <h1>LVS server3</h1>
   [root@foundation61 ~]# curl 172.25.61.100
   <h1>LVS server2</h1>
   

将主调度器上把keepalived服务停掉,在测试发现server2和server3仍然轮循,但ip已经漂移到副调度器上

[root@foundation61 ~]# curl 172.25.61.100
<h1>LVS server3</h1>
[root@foundation61 ~]# curl 172.25.61.100
<h1>LVS server2</h1>
[root@foundation61 ~]# curl 172.25.61.100
<h1>LVS server3</h1>
[root@foundation61 ~]# curl 172.25.61.100
<h1>LVS server2</h1>

	[root@server4 ~]# ip a
	1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
	    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
	    inet 127.0.0.1/8 scope host lo
	    inet6 ::1/128 scope host 
	       valid_lft forever preferred_lft forever
	2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
	    link/ether 52:54:00:3f:af:58 brd ff:ff:ff:ff:ff:ff
	    inet 172.25.61.4/24 brd 172.25.61.255 scope global eth0
	    inet 172.25.61.100/32 scope global eth0
	    inet6 fe80::5054:ff:fe3f:af58/64 scope link 
	       valid_lft forever preferred_lft forever