一、简介
不管是Keepalived还是Heartbeat做高可用,其高可用,都是站在服务器脚本去说的高可用,而不是服务的角度。
也就是说,如果服务器DOWN机或者网络出现故障,高可用是可以实现自动切换的。如果运行的服务,比如Nginx挂掉
这些高可用软件是意识不到的,需要自己写脚本去实现服务的切换。
二、安装配置Keepalived
复制内容到剪贴板
<code># ./configure # make # make install # cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ # cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/ # cp /usr/local/sbin/keepalived /usr/bin/ # chkconfig --add keepalived # mkdir /etc/keepalived/ # cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/</code>
编辑MASTER的主配置文件(MASTER: 1.1.1.1)
<code># vim /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id LVS_DEVEL } vrrp_script chk_nginx { script "/opt/monnginx.sh" interval 2 weight 2 } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass mdnginx } virtual_ipaddress { 1.1.1.100 } track_script { chk_nginx } }</code>
编辑BACKUP的主配置文件(BACKUP:1.1.1.2)
<code># vim /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id LVS_DEVEL } vrrp_script chk_nginx { script "/opt/monnginx.sh" interval 2 weight 2 } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass mdnginx } virtual_ipaddress { 1.1.1.100 } track_script { chk_nginx } }</code>
三、启动服务与脚本编写(主机和备机都要执行)
<code># service nginx start # service keepalived start</code>
编写监控Nginx的脚本
<code># vim /opt/monnginx.sh #!/bin/bash # author: honway.liu # date: 2013-03-15 if [ $(ps -C nginx --no-header | wc -l) -eq 0 ]; then service nginx start fi sleep 3 if [ $(ps -C nginx --no-header | wc -l) -eq 0 ]; then service keepalived stop fi</code>
改进脚本,加上报警功能。
<code># vim /opt/monnginx.sh #!/bin/bash # author: honway.liu # date: 2013-03-15 IPADDR=$(ip addr show eth0|awk '{print $2}' | sed -n 3p) contact=([email protected]) num=${#contact[@]} function email() { for ((i=0;i<num;i++));do echo "$IPADDR service problem" | mail -s "WARNING" ${contact[i]} -- -f [email protected] done } if [ $(ps -C nginx --no-header | wc -l) -eq 0 ]; then service nginx start fi email sleep 3 if [ $(ps -C nginx --no-header | wc -l) -eq 0 ]; then service keepalived stop email fi</code>
这里的报警使用的是139邮箱,在139邮箱里面设置有邮件的时候,通知到手机,并且以长短信的方式。
需要开户本机的sendmail服务。'
本文转自 gm100861 51CTO博客,原文链接:http://blog.51cto.com/gm100861/1155549