配置Keepalived实现HTTPD高可用

231gsd

一、环境说明

安装环境：

主机名	主机IP地址	集群角色	集群服务	虚拟IP地址
keepalived-master	192.168.1.1	MASTER(主节点)	HTTPD	192.168.1.3
keepalived-backup	192.168.1.2	BACKUP(备用节点)	HTTPD

官方地址：http://www.keepalived.org/

一、软件部署

分别在keepalived-master 与 keepalived-backup 安装keepalived软件

yum install openssl-devel -y

tar zxvf keepalived-1.2.20.tar.gz
./configure --sysconf=/etc --with-kernel-dir=/usr/src/kernels/2.6.32-431.el6.x86_64
make && make install
ln -s /usr/local/sbin/keepalived /sbin/
chkconfig --add keepalived
chkconfig --level 35 keepalived on

二、创建配置文件

Keepalived-master 配置文件：

vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_script check_httpd {
   script "killall -0 httpd"
   interval 2
   }

vrrp_instance HA_1 {
    state MASTER
    interface eth0
    virtual_router_id 80
    priority 100
    advert_int 2

    authentication {
        auth_type PASS
        auth_pass qweasdzxc
    }
   
    notify_master "/etc/keepalived/master.sh"
    notify_backup "/etc/keepalived/backup.sh"
    notify_fault "/etc/keepalived/fault.sh"

    track_script {
    check_httpd
    }

    virtual_ipaddress {
        192.168.1.3/24 dev eth0
    }
}

其中，master.sh文件内容为：

#!/bin/bash
LOGFILE=/var/log/keepalived-mysql-state.log
echo "[Master]" >> $LOGFILE
date >> $LOGFILE

其中，backup.sh文件内容为：

#!/bin/bash
LOGFILE=/var/log/keepalived-mysql-state.log
echo "[Backup]" >> $LOGFILE
date >> $LOGFILE

其中，fault.sh文件内容为：
#!/bin/bash
LOGFILE=/var/log/keepalived-mysql-state.log
echo "[Fault]" >> $LOGFILE
date >> $LOGFILE

Keepalived-backup 配置文件：

Keepalived-backup节点上的keepalived.conf配置文件与keepalived-master节点上基本相同，需要修改的地方有两个：
将“state MASTER”更改为 “state BACKUP”。
将priority 100 更改为一个较小的值，这里改为“priority 80”。

三、启动服务

分别在keepalived-master与 keepalived-backup节点启动keepalived服务

chkconfig --level 35 httpd on
/etc/init.d/httpd start
/etc/init.d/keepalived start

四、通过日志可查看启动信息

tail -f /var/log/keepalived-mysql-state.log
tail -f /var/log/messages

命令查看：ip add

五、模拟故障切换

停掉keepalived-master 节点的 HTTPD服务，发现192.168.1.3 的IP正确转移至 keepalived-backup节点上。

报错：
[iyunv@nfs-server ~]# /etc/init.d/keepalived start
正在启动 keepalived：/bin/bash: keepalived: command not found
                                                           [失败]
解决：
ln -s /usr/local/sbin/keepalived /usr/sbin/