[b]一、 启动LVS高可用集群服务 [/b] 首先，启动每个real server节点的服务： [root@localhost ~]# /etc/init.d/lvsrs start start LVS of REALServer 然后，分别在主备Director Server启动Keepalived服务： [root@DR1 ~]#/etc/init.d/Keepalived start [root@DR1 ~]#/ ipvsadm -L IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP bogon:http rr -> real-server1:http Route 1 1 0 -> real-server2:http Route 1 1 0 此时查看Keepalived服务的系统日志信息如下: [root@localhost ~]# tail -f /var/log/messages Feb 28 10:01:56 localhost Keepalived: Starting Keepalived v1.1.19 (02/27,2011) Feb 28 10:01:56 localhost Keepalived_healthcheckers: Netlink reflector reports IP 192.168.12.25 added Feb 28 10:01:56 localhost Keepalived_healthcheckers: Opening file '/etc/keepalived/keepalived.conf'. Feb 28 10:01:56 localhost Keepalived_healthcheckers: Configuration is using : 12063 Bytes Feb 28 10:01:56 localhost Keepalived: Starting Healthcheck child process, pid=4623 Feb 28 10:01:56 localhost Keepalived_vrrp: Netlink reflector reports IP 192.168.12.25 added Feb 28 10:01:56 localhost Keepalived: Starting VRRP child process, pid=4624 Feb 28 10:01:56 localhost Keepalived_healthcheckers: Activating healtchecker for service [192.168.12.246:80] Feb 28 10:01:56 localhost Keepalived_vrrp: Opening file '/etc/keepalived/keepalived.conf'. Feb 28 10:01:56 localhost Keepalived_healthcheckers: Activating healtchecker for service [192.168.12.237:80] Feb 28 10:01:57 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE Feb 28 10:01:58 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE Feb 28 10:01:58 localhost Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs. Feb 28 10:01:58 localhost Keepalived_healthcheckers: Netlink reflector reports IP 192.168.12.135 added Feb 28 10:01:58 localhost avahi-daemon[2778]: Registering new address record for 192.168.12.135 on eth0. [b]二、 高可用性功能测试[/b] 高可用性是通过LVS的两个Director Server完成的，为了模拟故障，我们先将主Director Server上面的Keepalived服务停止，然后观察备用Director Server上Keepalived的运行日志，信息如下： Feb 28 10:08:52 lvs-backup Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE Feb 28 10:08:54 lvs-backup Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE Feb 28 10:08:54 lvs-backup Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs. Feb 28 10:08:54 lvs-backup Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.12.135 Feb 28 10:08:54 lvs-backup Keepalived_vrrp: Netlink reflector reports IP 192.168.12.135 added Feb 28 10:08:54 lvs-backup Keepalived_healthcheckers: Netlink reflector reports IP 192.168.12.135 added Feb 28 10:08:54 lvs-backup avahi-daemon[3349]: Registering new address record for 192.168.12.135 on eth0. Feb 28 10:08:59 lvs-backup Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.12.135 从日志中可以看出，主机出现故障后，备机立刻检测到，此时备机变为MASTER角色，并且接管了主机的虚拟IP资源，最后将虚拟IP绑定在eth0设备上。 接着，重新启动主Director Server上的Keepalived服务，继续观察备用Director Server的日志状态： 备用Director Server的日志状态： Feb 28 10:12:11 lvs-backup Keepalived_vrrp: VRRP_Instance(VI_1) Received higher prio advert Feb 28 10:12:11 lvs-backup Keepalived_vrrp: VRRP_Instance(VI_1) Entering BACKUP STATE Feb 28 10:12:11 lvs-backup Keepalived_vrrp: VRRP_Instance(VI_1) removing protocol VIPs. Feb 28 10:12:11 lvs-backup Keepalived_vrrp: Netlink reflector reports IP 192.168.12.135 removed Feb 28 10:12:11 lvs-backup Keepalived_healthcheckers: Netlink reflector reports IP 192.168.12.135 removed Feb 28 10:12:11 lvs-backup avahi-daemon[3349]: Withdrawing address record for 192.168.12.135 on eth0. 从日志可知，备机在检测到主机重新恢复正常后，重新返回BACKUP角色，并且释放了虚拟IP资源。 [b]三、 负载均衡测试 [/b] 这里假定两个real server节点配置www服务的网页文件根目录均为/webdata/www目录，然后分别执行如下操作： 在real server1 执行： echo "This is real server1" /webdata/www/index.html 在real server2 执行： echo "This is real server2" /webdata/www/index.html 接着打开浏览器，访问http://192.168.12.135这个地址，然后不断刷新此页面，如果能分别看到“This is real server1”和“This is real server2”就表明LVS已经在进行负载均衡了。 [b]四、 故障切换测试 [/b] 故障切换是测试当某个节点出现故障后，Keepalived监控模块是否能及时发现，然后屏蔽故障节点，同时将服务转移到正常节点来执行。 这里我们将real server 1节点服务停掉，假定这个节点出现故障，然后查看主、备机日志信息，相关日志如下： Feb 28 10:14:12 localhost Keepalived_healthcheckers: TCP connection to [192.168.12.246:80] failed !!! Feb 28 10:14:12 localhost Keepalived_healthcheckers: Removing service [192.168.12.246:80] from VS [192.168.12.135:80] Feb 28 10:14:12 localhost Keepalived_healthcheckers: Remote SMTP server [192.168.12.1:25] connected. Feb 28 10:14:12 localhost Keepalived_healthcheckers: SMTP alert successfully sent. 通过日志可以看出，Keepalived监控模块检测到192.168.12.246这台主机出现故障后，将此节点从集群系统中剔除掉了。 此时访问http://192.168.12.135这个地址，应该只能看到“This is real server2”了，这是因为节点1出现故障，而Keepalived监控模块将节点1从集群系统中剔除了。 下面重新启动real server 1节点的服务，可以看到Keepalived日志信息如下： Feb 28 10:15:48 localhost Keepalived_healthcheckers: TCP connection to [192.168.12.246:80] success. Feb 28 10:15:48 localhost Keepalived_healthcheckers: Adding service [192.168.12.246:80] to VS [192.168.12.135:80] Feb 28 10:15:48 localhost Keepalived_healthcheckers: Remote SMTP server [192.168.12.1:25] connected. Feb 28 10:15:48 localhost Keepalived_healthcheckers: SMTP alert successfully sent. 从日志可知，Keepalived监控模块检测到192.168.12.246这台主机恢复正常后，又将此节点加入了集群系统中。 此时再次访问http://192.168.12.135这个地址，然后不断刷新此页面，应该又能分别看到“This is real server1”和“This is real server2”页面了，这说明在real server 1节点恢复正常后，Keepalived监控模块将此节点加入了集群系统中。 本文出自 “技术成就梦想” 博客