keepalived高可用 -02

一、keepalived高可用

1.环境准备

主机	              IP	                         身份

lb01	      10.10.0.5	                    keepalived master

lb02	      10.10.0.6                  	keepalived backup

web01	      172.16.1.7	                web端

web02	      172.16.1.8	                web端

db01          172.16.1.51	                数据库

  -	           10.10.0.3	                     VIP
  
# 注释  必须保证lb01、lb02两台一样

2、模拟keepalived搭建

1.保证两台lb01、lb02七层负载均衡一致

[root@lb01 conf.d]# scp linux12.wp.com.conf 172.16.1.6:/etc/nginx/conf.d/
root@172.16.1.6's password: 
linux12.wp.com.conf                                          100%  421   363.7KB/s   00:00  
[root@lb01 conf.d]# scp -r /etc/nginx/ssl_key 172.16.1.6:/etc/nginx/
root@172.16.1.6's password: 
server.key                                                   100% 1708    59.4KB/s   00:00    
server.crt                                                   100% 1342   766.1KB/s   00:00
#因为lb01 是使用了https协议。所以把假私钥，推送过去，搭建keepalived

2. 安装keepalived

[root@lb01 ~]# yum install -y keepalived
[root@lb02 ~]# yum install -y keepalived

3.配置keepalived

# 1、查找配置文件
[root@lb01 conf.d]# rpm -qc keepalived
/etc/keepalived/keepalived.conf
/etc/sysconfig/keepalived

# 2、配置主节点的配置文件
[root@lb01 ~]# vi /etc/keepalived/keepalived.conf   ## 删除全文 % d
 ## 全局配置
global_defs {
    router_id lb01  # 唯一的ID
}
vrrp_instance VI_1 {
    state MASTER  #状态 MASTER和BACKUP
    #nopreempt   #配置非抢占式，少一次断开，但是，两个srate 的状态必须都配置 BACKUP
    interface eth0 #网卡绑定
    virtual_router_id 50 ##组的名字
    priority 100    #优先级（权重）
    advert_int 1   # 监测心跳间隔时间
    authentication {  #认证类型
        auth_type PASS    #认证的密码
        auth_pass 1111  
    }
    virtual_ipaddress {
        10.10.0.102    #虚拟的VIP地址
    }
}

# 3、配置从节点
[root@lb02 ~]# vi /etc/keepalived/keepalived.conf
global_defs {
    router_id lb02
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 50
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        10.10.0.102
    }
}

4. 启动服务

[root@lb01 ~]# tail -f /var/log/messages
[root@lb01 ~]# systemctl start keepalived

[root@lb02 ~]# tail -f /var/log/messages
[root@lb02 ~]# systemctl restart keepalived

5.keepalived配置文件的重要架构介绍

## 讲解keepalived配置文件的几大架构
global_defs {             #全局配置
    router_id lb01        #身份识别--- 主机名
}
vrrp_instance VI_1 {      #配置VRRP协议

    state MASTER	        #状态，可写MASTER和BACKUP
    #nopreempt             #配置非抢占式，少一次断开，但是，两个srate 的状态必须都配置 BACKUP
    interface eth0        #绑定网卡
    virtual_router_id 50  #虚拟路由标示，可以理解为组名字
    priority 100          #优先级，越大优先级越高
    advert_int 1          #监测心跳间隔时间，每隔多少秒ping一下主的IP
    authentication {      #认证类型
        auth_type PASS    #认证类型
        auth_pass 1111    #认证的密码
    }
                                                                                               virtual_ipaddress {       #设置VI
        10.10.0.3          #虚拟的VIP地址
    }
}

6.keepalived开启日志

#配置keepalived
[root@lb01 ~]# vim /etc/sysconfig/keepalived
KEEPALIVED_OPTIONS="-D -d -S 0"

#配置rsyslog抓取日志
[root@lb01 ~]# vim /etc/rsyslog.conf
local0.*		/var/log/keepalived.log

#重启服务
[root@lb01 ~]# systemctl restart keepalived
[root@lb01 ~]# systemctl restart rsyslog

三、keepalived的抢占式与非抢占式

1.两个节点都启动的情况

#两个节点都启动时，由于节点1优先级高于节点2，所以只有节点1上有VIP，节点2为空
[root@lb01 ~]# ip addr | grep 10.10.0.3
    inet 10.10.0.3/32 scope global eth0
    
[root@lb02 ~]# ip addr | grep 10.10.0.3

2.停止主节点

[root@lb01 ~]# systemctl stop keepalived.service 
[root@lb01 ~]# ip addr | grep 10.10.0.3

#由于节点1keepalived down掉，节点2会自动接管节点1的工作，即VIP

[root@lb02 ~]# ip addr | grep 10.10.0.3
    inet 10.10.0.3/32 scope global eth0

3.重新启动主节点

#启动主节点
[root@lb01 ~]# systemctl start keepalived
[root@lb01 ~]# ip addr | grep 10.10.0.3
    inet 10.10.0.3/32 scope global eth0

#由于节点1优先级高于节点2，所以当节点1恢复时，会将VIP抢占回来

4.配置非抢占式

1.节点配置

`节点一配置
[root@lb01 ~]# vim /etc/keepalived/keepalived.conf 
... ...
vrrp_instance VI_1 {
    state BACKUP
    # nopreempt  开启非抢占式
    nopreempt
    priority 100
... ...
}
[root@lb01 ~]# systemctl restart keepalived

`节点二配置
[root@lb02 ~]# vim /etc/keepalived/keepalived.conf 
... ...
vrrp_instance VI_1 {
    state BACKUP
    #开启非抢占式  nopreempt
    nopreempt
    priority 90
... ...
}

[root@lb02 ~]# systemctl restart keepalived

# 注释 '配置非抢占式说明白
1.两个节点的state都必须配置为BACKUP
2.两个节点都必须加上配置 nopreempt
3.其中一个节点的优先级必须要高于另外一个节点的优先级。
两台服务器都角色状态启用nopreempt后，必须修改角色状态统一为BACKUP，唯一的区分就是优先级。

### cmd  输入 arp -a  
lb01 与10.10.0.3  一样