1:Keepalived的官方网址:http://www.keepalived.org/
2:Keepalived:可以实现高可靠;
高可靠的概念:
HA(High Available), 高可用性集群,是保证业务连续性的有效解决方案,一般有两个或两个以上的节点,且分为活动节点及备用节点。
3:高可靠软件:keepalived:
keepalive是一款可以实现高可靠的软件,通常部署在2台服务器上,分为一主一备。Keepalived可以对本机上的进程进行检测,一旦Master检测出某个进程出现问题,将自己切换成Backup状态,然后通知另外一个节点切换成Master状态。
4:keepalived的安装操作:
4.1:下载keepalived官网:http://keepalived.org
首先在两台机器上面部署两个Nginx,具体操作见上篇部署一台,另一台的部署过程省略:
将keepalived上传到虚拟机以后进行解压缩操作:
[root@master package]# tar -zxvf keepalived-1.2.19.tar.gz -C /home/hadoop/
解压缩以后进入到解压缩的目录里面:
[root@master package]# cd /home/hadoop/keepalived-1.2.19/
检查安装环境,并指定将来要安装的路径:
[root@master keepalived-1.2.19]# ./configure --prefix=/home/hadoop/keepalived 最后编译和安装:
[root@master keepalived-1.2.19]# make && make install
5:将Keepalived添加到系统服务中:
拷贝执行文件: [root@master keepalived-1.2.19]# cp /home/hadoop/keepalived/sbin/keepalived /usr/sbin/ 将init.d文件拷贝到etc下,加入开机启动项: [root@master keepalived-1.2.19]# cp /home/hadoop/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/keepalived 将keepalived文件拷贝到etc下: [root@master keepalived-1.2.19]# cp /home/hadoop/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ 创建keepalived文件夹: [root@master hadoop]# mkdir -p /etc/keepalived 将keepalived配置文件拷贝到etc下: [root@master hadoop]# cp /home/hadoop/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf 添加可执行权限: [root@master hadoop]# chmod +x /etc/init.d/keepalived 添加keepalived到开机启动: [root@master hadoop]# chkconfig --add keepalived [root@master hadoop]# chkconfig keepalived on
6:配置keepalived虚拟IP:修改配置文件:
[root@master hadoop]# vim /etc/keepalived/keepalived.conf
这里配置虚拟Ip就开始分keepalived的master节点和keepalived的backup节点:
#master节点 vrrp_instance VI_1 { state MASTER #指定A节点为主节点 备用节点上设置为BACKUP即可 interface eth0 #绑定虚拟IP的网络接口 virtual_router_id 51 #VRRP组名,两个节点的设置必须一样,以指明各个节点属于同一VRRP组 priority 100 #主节点的优先级(1-254之间),备用节点必须比主节点优先级低 advert_int 1 #组播信息发送间隔,两个节点设置必须一样 authentication { #设置验证信息,两个节点必须一致 auth_type PASS auth_pass 1111 } virtual_ipaddress { #指定虚拟IP, 两个节点设置必须一样, #如果两个nginx的ip分别是192.168.199.130,,...131,则此处的虚拟ip跟它俩同一个网段即可 192.168.199.141/24 } }
配置好master节点以后,可以配置BACKUP节点:
vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 99 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.199.141/24 } }
7:分别启动两台机器上面的keepalived:
给一个虚拟机设置两个ip地址方法: ip addr add 192.168.199.150 dev eth0
[root@master hadoop]# service keepalived start
最后测试一下:
如果杀掉master上的keepalived 进程,你会发现,在slaver即另外一台配置keepalived的机器上的eth0网卡多了一个ip地址
查看ip地址的命令:ip addr
这里测试的时候出现问题了,因为我的电脑安装的虚拟机都是同一个,所以第一台机器的ip配置在eth0,而其他的竟然配置在了eth1,而这里需要修改一下,ip所在的位置: 解决方法: 1:编辑/etc/udev/rules.d/70-persistent-net.rules,找到与ifconfig -a得出的MAC相同的一行(NAME='eth1'这一行),把它改为"NAME=eth0 ",然后把上面一行(NAME='eth0')删除掉。 vim /etc/udev/rules.d/70-persistent-net.rules SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:0c:29:bb:41:2b", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0" 2:编辑/etc/sysconfig/network-script/ifcfg-eth0,把MAC改为正确的,把UUID删掉。 3:编辑/etc/sysconf/network,把hostname也改一下。 4:重启生效!
8:配置keepalived心跳检查:
原理:
Keepalived并不跟nginx耦合,它俩完全不是一家人
但是keepalived提供一个机制:让用户自定义一个shell脚本去检测用户自己的程序,返回状态给keepalived就可以了;
master节点:
vrrp_instance VI_1 { state MASTER #指定A节点为主节点 备用节点上设置为BACKUP即可 interface eth0 #绑定虚拟IP的网络接口 virtual_router_id 51 #VRRP组名,两个节点的设置必须一样,以指明各个节点属于同一VRRP组 priority 100 #主节点的优先级(1-254之间),备用节点必须比主节点优先级低 advert_int 1 #组播信息发送间隔,两个节点设置必须一样 authentication { #设置验证信息,两个节点必须一致 auth_type PASS auth_pass 1111 } track_script { #跟踪用户程序脚本 chk_health } virtual_ipaddress { #指定虚拟IP, 两个节点设置必须一样, #如果两个nginx的ip分别是192.168.199.130,,...131,则此处的虚拟ip跟它俩同一个网段即可 192.168.199.141/24 } notify_master "/home/hadoop/keepalived/sbin/notify.sh master" notify_backup "/home/hadoop/keepalived/sbin/notify.sh backup" notify_fault "/home/hadoop/keepalived/sbin/notify.sh fault" }
添加切换通知脚本:
[root@master keepalived]# vim /home/hadoop/keepalived/sbin/notify.sh
#!/bin/bash case "$1" in master) /home/hadoop/nginx/sbin/nginx exit 0 ;; backup) /home/hadoop/nginx/sbin/nginx -s stop /home/hadoop/nginx/sbin/nginx exit 0 ;; fault) /home/hadoop/nginx/sbin/nginx -s stop exit 0 ;; *) echo 'Usage: notify.sh {master|backup|fault}' exit 1 ;; esac
添加执行权限:
[root@master keepalived]# chmod +x /home/hadoop/keepalived/sbin/notify.sh
然后配置一下slaver即另一台keepalived:
global_defs { } vrrp_script chk_health { script "[[ `ps -ef | grep nginx | grep -v grep | wc -l` -ge 2 ]] && exit 0 || exit 1" interval 1 weight -2 } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 1 priority 99 advert_int 1 authentication { auth_type PASS auth_pass 1111 } track_script { chk_health } virtual_ipaddress { 192.168.199.141/24 } notify_master "/home/hadoop/keepalived/sbin/notify.sh master" notify_backup "/home/hadoop/keepalived/sbin/notify.sh backup" notify_fault "/home/hadoop/keepalived/sbin/notify.sh fault" }
最后:
在第二台机器上添加notify.sh脚本
#分别在两台机器上启动keepalived
service keepalived start
chkconfig keepalived on