keepalived

keepalived，虚拟ip（vip）实践。
- keepalived介绍
- 版本
- 流程图
- 搭建
- - 基础设置
  - - 主机名
    - selinux
    - 关闭防火墙（所有机器）
    - hosts映射
  - keepalived设置
  - - vip
    - 准备rpm包
    - 配置
- 报错处理
- - 'keepalived_script' for script execution does not exist
  - .sh exited due to signal 15
  - Unsafe permissions found
- 配置详解
- 可参考

keepalived，虚拟ip（vip）实践。

keepalived介绍

keepalived是一个是集群管理中保证集群高可用的一个服务软件，它具备心跳检测的功能。比如运用在redis、nginx、greenplum上，则是具备主备切换的控制功能。
keepalived的主备切换方案的设计思想如下：
当 Master 与 Slave 均运作正常时, Master负责服务，Slave负责Standby；
当 Master 挂掉，Slave 正常时, Slave接管服务，同时关闭主从复制功能；
当 Master 恢复正常，则从Slave同步数据，同步数据之后关闭主从复制功能，恢复Master身份，于此同时Slave等待Master同步数据完成之后，恢复Slave身份。
然后依次循环。

版本

keepalived-1.3.9-1.el7.x86_64.rpm

流程图

搭建

基础设置

主机名

1.vi /etc/hostname (已设置可跳过) -----设置主机名

selinux

2.vi /etc/selinux/config (已设置可跳过) ------- SELINUX=disabled

关闭防火墙（所有机器）

设置开机启用防火墙：systemctl enable firewalld.service
设置开机禁用防火墙：systemctl disable firewalld.service
启动防火墙：systemctl start firewalld
关闭防火墙：systemctl stop firewalld
检查防火墙状态：systemctl status firewalld

hosts映射

vi /etc/hosts

keepalived设置

vip

192.168.60.221 keepalived主节点
192.168.60.222 keepalived备节点

192.168.60.100 虚拟ip(vip)

准备rpm包

两台机器目录/home/soft/keepalived/分别包含rpm包，位置自定义

rpm包文件位置：/home/soft/keepalived/keepalived-1.3.9-1.el7.x86_64.rpm

yum install keepalived-1.3.9-1.el7.x86_64.rpm
安装过程缺少依赖，补充依赖：http://rpmfind.net/linux/rpm2html/search.php?query=libverto-devel%28x86-64%29&submit=Search+…&system=&arch=
补充依赖包需要耐心，强烈建议使用在线yum安装，或者有离线的镜像yum

配置

yum install keepalived-1.3.9-1.el7.x86_64.rpm
安装完以后默认在/etc/keepalived，不建议更换位置

备份一份原有的配置
cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf-bnk

配置文件有很多暂时用不到的我就先删除掉了

vi /etc/keepalived/keepalived.conf

主
代码属于最初搭建使用的配置
图片是集成greenplum 高可用后的配置

! Configuration File for keepalivedglobal_defs {notification_email {acassen@firewall.locfailover@firewall.locsysadmin@firewall.loc}notification_email_from Alexandre.Cassen@firewall.locsmtp_server 192.168.60.221smtp_connect_timeout 30router_id LVS_DEVELscript_user rootenable_script_securityvrrp_skip_check_adv_addr#vrrp_strictvrrp_garp_interval 0vrrp_gna_interval 0
}vrrp_instance VI_1 {state BACKUPinterface eth0virtual_router_id 78priority 150advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.60.100}
}

备

! Configuration File for keepalivedglobal_defs {notification_email {acassen@firewall.locfailover@firewall.locsysadmin@firewall.loc}notification_email_from Alexandre.Cassen@firewall.locsmtp_server 192.168.60.222smtp_connect_timeout 30router_id LVS_DEVELscript_user rootenable_script_securityvrrp_skip_check_adv_addr#vrrp_strictvrrp_garp_interval 0vrrp_gna_interval 0
}vrrp_instance VI_1 {state BACKUPinterface eth0virtual_router_id 78priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.60.100}
}

参数简述：
state MASTER ：当前节点为master（会存在抢vip）
nopreempt : 配合state BACKUP (解决抢占vip)

notify：keepaclived启动执行，我自己测试出发了两次
notify_master：keepaclived启动，成为master后触发
notify_backup：keepaclived启动，成为backup触发

当第一个keepalived启动，会先执行一次notify_backup的脚本，然后执行一次notify_master的脚本

启动：systemctl start keepalived
停止：systemctl stop keepalived
查看：ps -ef|grep [k]eepalived
ip a

日志监控:
tail -f /var/log/messages

ps -ef|grep [k]eepalived

ping 192.168.60.100

虚拟ip成功

报错处理

‘keepalived_script’ for script execution does not exist

WARNING - default user ‘keepalived_script’ for script execution does not exist - please create.

这个错误的原因在于配置文件的错误，在global_defs中加入如下两行即可。
script_user root
enable_script_security

.sh exited due to signal 15

Keepalived_vrrp[29368]: /etc/keepalived/nginx_check.sh exited due to signal 15
vrrp_script{}中interval的间隔时间要大于脚本中的sleep时间

Unsafe permissions found

Unsafe permissions found for script ‘/etc/keepalived/XXXXXXX’
查看脚本权限，改成755.

如果还是报错Unsafe permissions，将脚本所有者改为root

配置详解

可参考

1.配置keepalived ping不通解决办法
2.nginx+keepalived集群高可用详细部署，keepalived安装启动报错问题(超详细)
3.Greenplum集群Master与Standby相互切换
4.Postgresl选择正确的关闭模式
5.实现主备路由自动切换 – keepalived
6.单台主机（CentOS7.3）安装Greenplum(5.20.1)
7.解决Keepalived脚本启动时warning、Unsafe