目录



一 keepalive介绍


1.1 keepalived 是什么

keepalived 是集群管理中保证集群高可用的一个服务软件,用来防止单点故障。


1.2 keepalived 工作原理

mysql主从之keepalive+MySQL高可用_sql

keepalived 是以VRRP 协议为实现基础的,VRRP 全称VirtualRouter Redundancy Protocol,即虚拟路由冗余协议。虚拟路由冗余协议,可以认为是实现路由器高可用的协议,即将N 台提供相同功能的路由器组成一个路由器组,这个组里面有一个master 和多个backup,master 上面有一个对外提供服务的vip(该路由器所在局域网内其他机器的默认路由为该vip),master 会发组播,当backup 收不到vrrp 包时就认为master 宕掉了,这时就需要根据VRRP 的优先级来选举一个backup 当master。这样的话就可以保证路由器的高可用了。

keepalived 主要有三个模块,分别是core、check 和vrrp。

core 模块为keepalived 的核心,负责主进程的启动、维护以及全局配置文件的加载和解析。

check 负责健康检查,包括常见的各种检查方式。

vrrp 模块是来实现VRRP 协议的。


1.3 实验环境

master1:192.168.132.121

master2:192.168.132.122

虚拟IP:192.168.132.120

双主环境

master1

mysql主从之keepalive+MySQL高可用_服务器_02

master1
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.132.122
Master_User: replication
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: master-bin.000003
Read_Master_Log_Pos: 4975
Relay_Log_File: relay-log.000003
Relay_Log_Pos: 913
Relay_Master_Log_File: master-bin.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 4975
Relay_Log_Space: 2618
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 2
Master_UUID: 662134df-a196-11e9-b432-000c2963fd11
Master_Info_File: /data/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set: 662134df-a196-11e9-b432-000c2963fd11:1-7
Executed_Gtid_Set: 63a7f26f-a196-11e9-a2b2-000c2991dd19:1-18,
662134df-a196-11e9-b432-000c2963fd11:1-7
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name:

mysql主从之keepalive+MySQL高可用_服务器_02


master2

mysql主从之keepalive+MySQL高可用_服务器_02

mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.132.121
Master_User: replication
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: master-bin.000008
Read_Master_Log_Pos: 650
Relay_Log_File: relay-log.000008
Relay_Log_Pos: 865
Relay_Master_Log_File: master-bin.000008
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 650
Relay_Log_Space: 2098
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
Master_UUID: 63a7f26f-a196-11e9-a2b2-000c2991dd19
Master_Info_File: /data/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set: 63a7f26f-a196-11e9-a2b2-000c2991dd19:1-18
Executed_Gtid_Set: 63a7f26f-a196-11e9-a2b2-000c2991dd19:1-18,
662134df-a196-11e9-b432-000c2963fd11:1-7
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:

mysql主从之keepalive+MySQL高可用_服务器_02

​回到顶部​

 二 配置keepalive

2.1 开始安装keepalived

[root@master1 ~]# cd /usr/local/src/

[root@master1 src]# wget https://www.keepalived.org/software/keepalived-2.0.17.tar.gz

[root@master1 src]# tar -xf keepalived-2.0.17.tar.gz

[root@master1 src]# cd keepalived-2.0.17

[root@master1 keepalived-2.0.17]# yum install openssl* libnl‐dev* gcc-c++

[root@master1 keepalived-2.0.17]# ./configure --prefix=/usr/local/keepalived

[root@master1 keepalived-2.0.17]# make

[root@master1 keepalived-2.0.17]# make install

[root@master1 keepalived-2.0.17]# cd /usr/local/keepalived/sbin/

[root@master1 sbin]# ll

-rwxr-xr-x. 1 root root 2381368 Jul 9 11:59 keepalived

[root@master1 sbin]# cp keepalived /usr/sbin/

[root@master1 sbin]# ll /usr/sbin/keepalived

-rwxr-xr-x. 1 root root 2381368 Jul 9 12:01 /usr/sbin/keepalived

[root@master1 sbin]# systemctl list-unit-files|grep keepalived

mysql主从之keepalive+MySQL高可用_服务器_06

[root@master1 sbin]# systemctl enable keepalived

[root@master1 sbin]# systemctl list-unit-files|grep keepalived

mysql主从之keepalive+MySQL高可用_sql_07

[root@master1 sbin]# mkdir /etc/keepalived

[root@master1 sbin]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/

[root@master1 sbin]# ll /etc/keepalived/

-rw-r--r--. 1 root root 3550 Jul 9 12:06 keepalived.conf


2.2 配置keepailve

root@master1 keepalived-2.0.17]# vim /etc/keepalived/keepalived.conf

mysql主从之keepalive+MySQL高可用_服务器_02

! Configuration File for keepalived

global_defs {
router_id db01
}

vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51
priority 100
nopreempt
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.132.120
}
}
virtual_server 192.168.132.120 3306 {
delay_loop 6
persistence_timeout 50
protocol TCP

real_server 192.168.132.121 3306 {
notify_down /etc/keepalived/kill_keepalived.sh
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
connect_port 3306
delay_before_retry 3
}
}
}

mysql主从之keepalive+MySQL高可用_服务器_02

配置简介

mysql主从之keepalive+MySQL高可用_服务器_02

global_defs 区域主要是配置故障发生时的通知对象以及机器标识
notification_email_from Alexandre.Cassen@firewall.loc //通知邮件从哪个地址发出
smtp_server 192.168.200.1 //通知邮件的smtp 地址
smtp_connect_timeout 30 //连接smtp 服务器的超时时间
router_id db01 // 标识本节点的字符串, 通常为hostname
vrrp_skip_check_adv_addr
vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_instance VI_1 {//VRRP 实例state MASTER // MASTER 或BACKUP,为了防止脑裂现象,主备均需要设置为backup 模式,master 模式会抢占VIP
interface eth0 //节点固有IP(非VIP)的网卡,用来发VRRP 包
virtual_router_id 51 //取值在0-255 之间,用来区分多个instance 的VRRP 组播priority 100 //优先级,同一个vrrp_instance 的MASTER优先级必须比BACKUP 高nopreempt //非抢占,配合backup,防止切换后,主库服务恢复正常后,IP 漂移过来advert_int 1// MASTER 与BACKUP 负载均衡器之间同步检查的时间间隔,单位为秒。
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress { //虚拟ip 地址,可以有多个地址,每个地址占一行,不需要子网掩码
192.168.132.120
}
}
virtual_server 192.168.200.16 3306 {
delay_loop 6 //健康检查间隔,单位为秒
persistence_timeout 50 // 会话保持时间,就是把用户请求转发给同一个服务器
protocol TCP //转发协议,有TCP 和UDP 两种,一般用TCP
real_server 192.168.132.121 3306 { //真实服务器,包括IP和端口号
notify_down kill_keepalived.sh
TCP_CHECK { #通过tcpcheck 判断RealServer 的健康状态
connect_timeout 3 #连接超时时间
nb_get_retry 3 #重连次数
delay_before_retry 3 #重连时间间隔
connect_port 3306 #检测端口
}
}
}

mysql主从之keepalive+MySQL高可用_服务器_02

 keepalived 服务配置

#设置不抢占模式(DB1 设置即可)

nopreempt

#虚拟路由标识,这个标识是一个数字(1‐255),在一个VRRP

实例中主备服务器ID 必须一样

virtual_router_id 68

#优先级,数字越大优先级越高,在一个实例中主服务器优

先级要高于备服务器

priority 100 #从服务器99

#设置主备之间同步检查的时间间隔单位秒

advert_int 1

[root@master1 keepalived-2.0.17]# vim /etc/keepalived/kill_keepalived.sh

[root@master1 keepalived-2.0.17]# chmod +x /etc/keepalived/kill_keepalived.sh

#!/bin/bash
kill -9 $(cat /var/run/keepalived.pid)

[root@master1 keepalived-2.0.17]# systemctl start  keepalived

[root@master1 keepalived-2.0.17]# cat /var/run/keepalived.pid 

16287

master2相同做法

配置文件

[root@master2 sbin]# cat /etc/keepalived/keepalived.conf

mysql主从之keepalive+MySQL高可用_服务器_02

[root@master2 sbin]# cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

bal_defs {
router_id db02
}

vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51
priority 90
nopreempt
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.132.120
}
}
virtual_server 192.168.132.120 3306 {
delay_loop 6
persistence_timeout 50
protocol TCP

real_server 192.168.132.122 3306 {
notify_down /etc/keepalived/kill_keepalived.sh
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
connect_port 3306
delay_before_retry 3
}
}
}

mysql主从之keepalive+MySQL高可用_服务器_02


2.3 检查状态

[root@master2 ~]# systemctl status keepalived

mysql主从之keepalive+MySQL高可用_mysql_14

 [root@master2 ~]# ps -ef|grep keepalived

mysql主从之keepalive+MySQL高可用_服务器_15

[root@master1 ~]# ip addr

mysql主从之keepalive+MySQL高可用_服务器_02

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:91:dd:19 brd ff:ff:ff:ff:ff:ff
inet 192.168.132.121/24 brd 192.168.132.255 scope global ens33
valid_lft forever preferred_lft forever
inet 192.168.132.120/32 scope global ens33 #虚拟IP地址
valid_lft forever preferred_lft forever
inet6 fe80::b469:7426:8024:a47c/64 scope link
valid_lft forever preferred_lft forever
3: ens34: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:91:dd:23 brd ff:ff:ff:ff:ff:ff
inet 192.168.43.85/24 brd 192.168.43.255 scope global dynamic ens34
valid_lft 2810sec preferred_lft 2810sec
inet 192.168.254.121/24 brd 192.168.254.255 scope global ens34
valid_lft forever preferred_lft forever
inet6 fe80::4d8:1809:407a:5c0a/64 scope link
valid_lft forever preferred_lft forever

mysql主从之keepalive+MySQL高可用_服务器_02

 master2查看

mysql主从之keepalive+MySQL高可用_服务器_02

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:63:fd:11 brd ff:ff:ff:ff:ff:ff
inet 192.168.132.122/24 brd 192.168.132.255 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::5d18:db0b:8907:de34/64 scope link
valid_lft forever preferred_lft forever
3: ens34: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:63:fd:1b brd ff:ff:ff:ff:ff:ff
inet 192.168.254.122/24 brd 192.168.254.255 scope global ens34
valid_lft forever preferred_lft forever
inet6 fe80::c3d5:5055:468a:94f8/64 scope link
valid_lft forever preferred_lft forever

mysql主从之keepalive+MySQL高可用_服务器_02

​回到顶部​

 三 验证

授权后尝试使用192.168.132.20这个IP连接数据库

mysql> grant all on *.*  to root@192.168.132.123 identified by '1234567';
mysql> flush privileges;

[root@slave ~]# mysql -ureplication -h192.168.132.120 -p1234567

mysql主从之keepalive+MySQL高可用_服务器_02

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| master1 |
| master2 |
| mysql |
| performance_schema |
| sys |
+--------------------+

mysql主从之keepalive+MySQL高可用_服务器_02

 关闭192.168.132.121的mysqld

[root@master1 ~]# systemctl stop mysqld

[root@master1 ~]# ip addr

mysql主从之keepalive+MySQL高可用_服务器_02

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:91:dd:19 brd ff:ff:ff:ff:ff:ff
inet 192.168.132.121/24 brd 192.168.132.255 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::b469:7426:8024:a47c/64 scope link
valid_lft forever preferred_lft forever
3: ens34: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:91:dd:23 brd ff:ff:ff:ff:ff:ff
inet 192.168.43.85/24 brd 192.168.43.255 scope global dynamic ens34
valid_lft 3348sec preferred_lft 3348sec
inet 192.168.254.121/24 brd 192.168.254.255 scope global ens34
valid_lft forever preferred_lft forever
inet6 fe80::4d8:1809:407a:5c0a/64 scope link
valid_lft forever preferred_lft forever

mysql主从之keepalive+MySQL高可用_服务器_02

查看master2

[root@master2 ~]# ip addr

mysql主从之keepalive+MySQL高可用_服务器_02

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:63:fd:11 brd ff:ff:ff:ff:ff:ff
inet 192.168.132.122/24 brd 192.168.132.255 scope global ens33
valid_lft forever preferred_lft forever
inet 192.168.132.120/32 scope global ens33 #虚拟IP已经转移过来
valid_lft forever preferred_lft forever
inet6 fe80::5d18:db0b:8907:de34/64 scope link
valid_lft forever preferred_lft forever
3: ens34: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:63:fd:1b brd ff:ff:ff:ff:ff:ff
inet 192.168.254.122/24 brd 192.168.254.255 scope global ens34
valid_lft forever preferred_lft forever
inet6 fe80::c3d5:5055:468a:94f8/64 scope link
valid_lft forever preferred_lft forever

mysql主从之keepalive+MySQL高可用_服务器_02

使用slave连接

mysql主从之keepalive+MySQL高可用_服务器_02

[root@slave ~]# mysql -uroot -h192.168.132.120 -p1234567
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| master1 |
| master2 |
| mysql |
| performance_schema |
| sys |
+--------------------+

mysql主从之keepalive+MySQL高可用_服务器_02

依然可以访问,双主的高可用配置完成

在master1开启MySQL和keepalive后,虚拟IP并不会抢占回来,是因为设置的是非抢占模式,防止虚拟IP跳动影响性能