部署：keepalived-1.3.5+MHA部署mysql集群

MHA：

MHA工作原理总结为以下几条：

从宕机崩溃的master保存二进制日志事件（binlog events）；
识别含有最新更新的slave；
应用差异的中继日志（relay log）到其他slave；
应用从master保存的二进制日志事件（binlog events）；
提升一个slave为新master；
使用其他的slave连接新的master进行复制。

MHA特点:

故障切换时间 10-30秒
自动监控Master以及故障转移
在线切换Master到异机

1.环境介绍

服务器角色	IP	节点	端口	职责
manager、master	192.168.163.3	mha1	3310	监控、主master
slave1	192.168.163.16	mha2	3310	从slave
slave2	192.168.163.20	mha3	3310	从slave

OS：CentOS7.8

MySQL：Mysql-5.7.23

MHA：mha4mysql-manager-0.58-0.el7.centos.noarch.rpm

mha4mysql-node-0.58-0.el7.centos.noarch.rpm

Keepalived：keepalived-1.3.5-19.el7.x86_64

关闭防火墙

systemctl stop firewalld

systemctl disable firewalld

1.1配置yum源

mha需要很多依赖包，很过国内的网络yum源没有一些依赖，可直接使用下面的yum源，会省去大部分时间

cat > /etc/yum.repos.d/epel.repo << EOF

[epel]

name=Extra Packages for Enterprise Linux 7 - $basearch

failovermethod=priority

enabled=1

gpgcheck=0

mirrorlist=http://mirrors.fedoraproject.org/mirrorlist?repo=epel-7&arch=$basearch

EOF

1.2安装依赖包

三台主机都需要安装依赖包

yum install perl-DBI perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes perl-Params-Validate perl-DateTime -y

yum install cpan perl-ExtUtils-Embed perl-ExtUtils-CBuilder perl-ExtUtils-MakeMaker -y

1.3安装软件

mha1:

三台主机都选择安装manager，node节点都安装

rpm -ivh mha4mysql-manager-0.58-0.el7.centos.noarch.rpm

rpm -ivh mha4mysql-node-0.58-0.el7.centos.noarch.rpm

mha2:

rpm -ivh mha4mysql-node-0.58-0.el7.centos.noarch.rpm

mha3:

rpm -ivh mha4mysql-node-0.58-0.el7.centos.noarch.rpm

1.4修改主机名和hosts文件

三台主机都修改

[root@mha1 ~]# cat /etc/hosts

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4

::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

192.168.163.3 mha1

192.168.163.16 mha2

192.168.163.20 mha3

1.5 ssh 互通环境

mha1：

ssh-keygen

ssh-copy-id -i ~/.ssh/id_rsa.pub root@192.168.163.3

ssh-copy-id -i ~/.ssh/id_rsa.pub root@192.168.163.16

ssh-copy-id -i ~/.ssh/id_rsa.pub root@192.168.163.20

三台主机依次登录测试，直到可以直接登录其他主机

ssh 192.168.163.3

ssh 192.168.16316

ssh 192.168.163.20

2. mysql安装部署

2.1mysql配置文件

注意更改server_id，在同一个集群中，更改为不同的server_id

[root@mha1 ~]# vim /data/3310/my.cnf

[mysqld]

basedir=/application/mysql

datadir=/data/3310/data

socket=/data/3310/mysql.sock

log_error=/data/3310/mysql.log

port=3310

server_id=331003

log_bin=/data/3310/mysql-bin

gtid-mode=on

enforce-gtid-consistency=true

slow_query_log=ON

skip-name-resolve              #  建议加上 非必须项

relay_log_purge = 0            #  关闭自动清理中继日志

log_slave_updates = 1          #  从库通过binlog更新的数据写进从库二进制日志中，必加，否则切换后可能丢失数据

relay-log = relay-log

2.2加入启动服务

[root@mha1 ~]# vim /etc/systemd/system/mysqld3310.service

[Unit]

Description=MySQL Server

Documentation=man:mysqld(8)

Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html

After=network.target

After=syslog.target

[Install]

WantedBy=multi-user.target

[Service]

User=mysql

Group=mysql

ExecStart=/application/mysql/bin/mysqld --defaults-file=/data/3310/my.cnf

LimitNOFILE = 5000

2.3初始化mysql

/application/mysql/bin/mysqld --initialize-insecure --user=mysql --basedir=/application/mysql --datadir=/data/3310/data

2.4启动mysql

systemctl start mysqld3310

systemctl enable mysqld3310

3.一主两从搭建

3.1 mha1

mysql> create user 'slave'@'192.168.163.%' identified by '123';

mysql> create user  mha@'192.168.163.%' identified by '123';

mysql> grant replication slave on *.* to slave@'192.168.163.%' identified by '123';

mysql> grant all on *.* to   mha@'192.168.163.%';

mysql> flush privileges;

也可以选择用mysqldump的方式来恢复从库，此时是新建的库，并没有数据。

mysqldump -uroot -p123 -S /data/3310/mysql.sock -A --master-data=2 --single-transaction -R -E --triggers >/tmp/full.sql

从库source /tmp/full.sql

查看主库master状态

3.2 mha2

mysql> change master to master_host='192.168.163.3',master_user='slave',master_port=3310,master_password='123',master_log_file='master-log.000003',master_log_pos=234;

Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in binary log index file'

主库添加log-bin-index 参数后，从库报这个错误：Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in binary log index file'

mysql> stop slave;

Query OK, 0 rows affected (0.00 sec)

mysql> reset slave;

Query OK, 0 rows affected (0.01 sec)

mysql> start slave;

Query OK, 0 rows affected (0.00 sec)

mysql> show slave status\G;

3.3 mha3

mysql> change master to master_host='192.168.163.3',master_user='slave',master_port=3310,master_password='123',master_log_file='master-log.000003',master_log_pos=234;

mysql> stop slave;

Query OK, 0 rows affected (0.00 sec)

mysql> reset slave;

Query OK, 0 rows affected (0.01 sec)

mysql> start slave;

Query OK, 0 rows affected (0.00 sec)

4.mha搭建

Manager工具

masterha_check_ssh 检查MHA的SSH配置状况

masterha_check_repl 检查MySQL复制状况

masterha_manger 启动MHA

masterha_check_status 检测当前MHA运行状态

masterha_master_monitor 检测master是否宕机

masterha_master_switch 控制故障转移（自动或者手动）

masterha_conf_host 添加或删除配置的server信息

Node工具

save_binary_logs 保存和复制master的二进制日志

apply_diff_relay_logs 识别差异的中继日志事件并应用于其它slave

filter_mysqlbinlog 去除不必要的ROLLBACK事件(MHA已不再使用这个工具)

purge_relay_logs 清除中继日志(不会阻塞SQL线程)

启动mha

nohup masterha_manager --conf=/etc/mha_master/mha.cnf --remove_dead_master --ignore_last_failover < /dev/null > /etc/mha_master/manager.log 2>&1 &

关闭mha

masterha_stop --conf=/etc/mha_master/mha.cnf

集群状态检查

masterha_check_status --conf=/etc/mha_master/mha.cnf

集群连接检查

masterha_check_ssh--conf=/etc/mha_master/mha.cnf

集群复制检查

masterha_check_repl --conf=/etc/mha_master/mha.cnf

集群切换

masterha_master_switch --conf=/etc/mha_master/mha.cnf --master_state=alive --new_master_host=192.168.163.16 --new_master_port=3310 --orig_master_is_new_slave --running_updates_limit=10000

4.1安装软件

见1.3 已安装

4.2配置文件

mha1:

mkdir -p /etc/mha_master/app1

touch /etc/mha_master/manager.log

cat > /etc/mha_master/mha.cnf <<EOF

[server default]

manager_log=/etc/mha_master/manager.log

manager_workdir=/etc/mha_master/app1

password=123

ping_interval=1

remote_workdir=/tmp

repl_password=123

repl_user=slave

ssh_user=root

user=mha

[server1]

candidate_master=1

hostname=192.168.163.3

port=3310

ssh_port=22

[server2]

candidate_master=1

hostname=192.168.163.16

port=3310

ssh_port=22

[server3]

candidate_master=1

hostname=192.168.163.20

port=3310

ssh_port=22

EOF

参数详情见网络

4.3集群状态检查

MHA连接检查

[root@mha1 ~]# masterha_check_ssh --conf=/etc/mha_master/mha.cnf

MHA复制检查

[root@mha1 ~]# masterha_check_ssh --conf=/etc/mha_master/mha.cnf

4.4开启集群

[root@mha1 ~]# nohup masterha_manager --conf=/etc/mha_master/mha.cnf  --remove_dead_master --ignore_last_failover < /dev/null > /etc/mha_master/manager.log 2>&1 &

集群状态

[root@mha1 ~]# masterha_check_status --conf=/etc/mha_master/mha.cnf

5.手动故障切换

5.1停止mha监控

停止集群

[root@mha1 ~]# masterha_stop --conf=/etc/mha_master/mha.cnf

5.2切换主库为mha2

[root@mha1 ~]# masterha_master_switch --conf=/etc/mha_master/mha.cnf --master_state=alive --new_master_host=192.168.163.16 --new_master_port=3310 --orig_master_is_new_slave --running_updates_limit=10000

Sat Feb 20 09:44:43 2021 - [info] MHA::MasterRotate version 0.58.

Sat Feb 20 09:44:43 2021 - [info] Starting online master switch..

Sat Feb 20 09:44:43 2021 - [info]

Sat Feb 20 09:44:43 2021 - [info] * Phase 1: Configuration Check Phase..

Sat Feb 20 09:44:43 2021 - [info]

Sat Feb 20 09:44:43 2021 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.

Sat Feb 20 09:44:43 2021 - [info] Reading application default configuration from /etc/mha_master/mha.cnf..

Sat Feb 20 09:44:43 2021 - [info] Reading server configuration from /etc/mha_master/mha.cnf..

Sat Feb 20 09:44:44 2021 - [info] GTID failover mode = 1

Sat Feb 20 09:44:44 2021 - [info] Current Alive Master: 192.168.163.3(192.168.163.3:3310)

Sat Feb 20 09:44:44 2021 - [info] Alive Slaves:

Sat Feb 20 09:44:44 2021 - [info]   192.168.163.16(192.168.163.16:3310)  Version=5.7.32-log (oldest major version between slaves) log-bin:enabled

Sat Feb 20 09:44:44 2021 - [info]     GTID ON

Sat Feb 20 09:44:44 2021 - [info]     Replicating from 192.168.163.3(192.168.163.3:3310)

Sat Feb 20 09:44:44 2021 - [info]     Primary candidate for the new Master (candidate_master is set)

Sat Feb 20 09:44:44 2021 - [info]   192.168.163.20(192.168.163.20:3310)  Version=5.7.32-log (oldest major version between slaves) log-bin:enabled

Sat Feb 20 09:44:44 2021 - [info]     GTID ON

Sat Feb 20 09:44:44 2021 - [info]     Replicating from 192.168.163.3(192.168.163.3:3310)

Sat Feb 20 09:44:44 2021 - [info]     Primary candidate for the new Master (candidate_master is set)

It is better to execute FLUSH NO_WRITE_TO_BINLOG TABLES on the master before switching. Is it ok to execute on 192.168.163.3(192.168.163.3:3310)? (YES/no): yes

Sat Feb 20 09:44:47 2021 - [info] Executing FLUSH NO_WRITE_TO_BINLOG TABLES. This may take long time..

Sat Feb 20 09:44:47 2021 - [info]  ok.

Sat Feb 20 09:44:47 2021 - [info] Checking MHA is not monitoring or doing failover..

Sat Feb 20 09:44:47 2021 - [info] Checking replication health on 192.168.163.16..

Sat Feb 20 09:44:47 2021 - [info]  ok.

Sat Feb 20 09:44:47 2021 - [info] Checking replication health on 192.168.163.20..

Sat Feb 20 09:44:47 2021 - [info]  ok.

Sat Feb 20 09:44:47 2021 - [info] 192.168.163.16 can be new master.

Sat Feb 20 09:44:47 2021 - [info]

From:

192.168.163.3(192.168.163.3:3310) (current master)

 +--192.168.163.16(192.168.163.16:3310)

 +--192.168.163.20(192.168.163.20:3310)

To:

192.168.163.16(192.168.163.16:3310) (new master)

 +--192.168.163.20(192.168.163.20:3310)

 +--192.168.163.3(192.168.163.3:3310)

Starting master switch from 192.168.163.3(192.168.163.3:3310) to 192.168.163.16(192.168.163.16:3310)? (yes/NO): yes

Sat Feb 20 09:44:49 2021 - [info] Checking whether 192.168.163.16(192.168.163.16:3310) is ok for the new master..

Sat Feb 20 09:44:49 2021 - [info]  ok.

Sat Feb 20 09:44:49 2021 - [info] 192.168.163.3(192.168.163.3:3310): SHOW SLAVE STATUS returned empty result. To check replication filtering rules, temporarily executing CHANGE MASTER to a dummy host.

Sat Feb 20 09:44:49 2021 - [info] 192.168.163.3(192.168.163.3:3310): Resetting slave pointing to the dummy host.

Sat Feb 20 09:44:49 2021 - [info] ** Phase 1: Configuration Check Phase completed.

Sat Feb 20 09:44:49 2021 - [info]

Sat Feb 20 09:44:49 2021 - [info] * Phase 2: Rejecting updates Phase..

Sat Feb 20 09:44:49 2021 - [info]

master_ip_online_change_script is not defined. If you do not disable writes on the current master manually, applications keep writing on the current master. Is it ok to proceed? (yes/NO): yes

Sat Feb 20 09:44:50 2021 - [info] Locking all tables on the orig master to reject updates from everybody (including root):

Sat Feb 20 09:44:50 2021 - [info] Executing FLUSH TABLES WITH READ LOCK..

Sat Feb 20 09:44:50 2021 - [info]  ok.

Sat Feb 20 09:44:50 2021 - [info] Orig master binlog:pos is mysql-bin.000002:194.

Sat Feb 20 09:44:50 2021 - [info]  Waiting to execute all relay logs on 192.168.163.16(192.168.163.16:3310)..

Sat Feb 20 09:44:50 2021 - [info]  master_pos_wait(mysql-bin.000002:194) completed on 192.168.163.16(192.168.163.16:3310). Executed 0 events.

Sat Feb 20 09:44:50 2021 - [info]   done.

Sat Feb 20 09:44:50 2021 - [info] Getting new master's binlog name and position..

Sat Feb 20 09:44:50 2021 - [info]  mysql-bin.000001:2509

Sat Feb 20 09:44:50 2021 - [info]  All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='192.168.163.16', MASTER_PORT=3310, MASTER_AUTO_POSITION=1, MASTER_USER='slave', MASTER_PASSWORD='xxx';

Sat Feb 20 09:44:50 2021 - [info]

Sat Feb 20 09:44:50 2021 - [info] * Switching slaves in parallel..

Sat Feb 20 09:44:50 2021 - [info]

Sat Feb 20 09:44:50 2021 - [info] -- Slave switch on host 192.168.163.20(192.168.163.20:3310) started, pid: 1716

Sat Feb 20 09:44:50 2021 - [info]

Sat Feb 20 09:44:52 2021 - [info] Log messages from 192.168.163.20 ...

Sat Feb 20 09:44:52 2021 - [info]

Sat Feb 20 09:44:50 2021 - [info]  Waiting to execute all relay logs on 192.168.163.20(192.168.163.20:3310)..

Sat Feb 20 09:44:50 2021 - [info]  master_pos_wait(mysql-bin.000002:194) completed on 192.168.163.20(192.168.163.20:3310). Executed 0 events.

Sat Feb 20 09:44:50 2021 - [info]   done.

Sat Feb 20 09:44:50 2021 - [info]  Resetting slave 192.168.163.20(192.168.163.20:3310) and starting replication from the new master 192.168.163.16(192.168.163.16:3310)..

Sat Feb 20 09:44:50 2021 - [info]  Executed CHANGE MASTER.

Sat Feb 20 09:44:51 2021 - [info]  Slave started.

Sat Feb 20 09:44:52 2021 - [info] End of log messages from 192.168.163.20 ...

Sat Feb 20 09:44:52 2021 - [info]

Sat Feb 20 09:44:52 2021 - [info] -- Slave switch on host 192.168.163.20(192.168.163.20:3310) succeeded.

Sat Feb 20 09:44:52 2021 - [info] Unlocking all tables on the orig master:

Sat Feb 20 09:44:52 2021 - [info] Executing UNLOCK TABLES..

Sat Feb 20 09:44:52 2021 - [info]  ok.

Sat Feb 20 09:44:52 2021 - [info] Starting orig master as a new slave..

Sat Feb 20 09:44:52 2021 - [info]  Resetting slave 192.168.163.3(192.168.163.3:3310) and starting replication from the new master 192.168.163.16(192.168.163.16:3310)..

Sat Feb 20 09:44:52 2021 - [info]  Executed CHANGE MASTER.

Sat Feb 20 09:44:53 2021 - [info]  Slave started.

Sat Feb 20 09:44:53 2021 - [info] All new slave servers switched successfully.

Sat Feb 20 09:44:53 2021 - [info]

Sat Feb 20 09:44:53 2021 - [info] * Phase 5: New master cleanup phase..

Sat Feb 20 09:44:53 2021 - [info]

Sat Feb 20 09:44:53 2021 - [info]  192.168.163.16: Resetting slave info succeeded.

Sat Feb 20 09:44:53 2021 - [info] Switching master to 192.168.163.16(192.168.163.16:3310) completed successfully.

如果失败：

5.3启动mha

[root@mha1 ~]# nohup masterha_manager --conf=/etc/mha_master/mha.cnf  --remove_dead_master --ignore_last_failover < /dev/null > /etc/mha_master/manager.log 2>&1 &

[1]1733

5.4查看目前集群状态

状态检查已经显示master节点切换到mha2上

[root@mha1 ~]# masterha_check_status --conf=/etc/mha_master/mha.cnf

mha (pid:1733) is running(0:PING_OK), master:192.168.163.16

mha1:原master

mha2:现在的master主库 192.168.163.16

可以看到现在集群软件仍然部署在192.168.163.3上，只不过主节点现在切换到了mha2上

mha3: 192.168.163.20

6.自动故障切换

根据手动切换的方法可以将master从mha2切换为mha1

6.1安装keepalived

[root@mha3 ~ 10:21:01]# yum install keepalived -y

6.2配置文件

[root@mha1 ~]# vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {

   notification_email {

     admin@test.com

   }

   notification_email_from admin@test.com

   smtp_server 127.0.0.1

   smtp_connect_timeout 30

   router_id MYSQL_HA

}

vrrp_script chk_mysql {

    script "killall -0 mysql"         # 监控mysql健康性脚本

    insterval 1

    weight -10

} 

vrrp_instance VI_1 {

    state BACKUP

    interface ens33             #根据实际网络接口进行更改

    virtual_router_id 51

    priority 100               #优先级，mha1设置100，mha2设置99，mha3设置98

    advert_int 1

    nopreempt                  #不主动抢占资源，只在master上设置

    authentication {

        auth_type PASS

        auth_pass 1111

    }

    virtual_ipaddress {

        192.168.163.23

    }

    track_script {

    chk_mysql

    }

}

6.3传输配置文件

[root@mha1 ~]# scp /etc/keepalived/keepalived.conf root@192.168.163.16:/etc/keepalived/keepalived.conf

keepalived.conf                                                                                                                                                                 100% 1290   836.2KB/s   00:00

[root@mha1 ~]# scp /etc/keepalived/keepalived.conf root@192.168.163.20:/etc/keepalived/keepalived.conf

keepalived.conf

6.4修改keepalived.conf

mha2：

priority 99 #优先级，mha1设置100，mha2设置99，mha3设置98

mha3：

priority 98 #优先级，mha1设置100，mha2设置99，mha3设置98

6.5启动keepalived

[root@mha1 ~]# systemctl start keepalived

[root@mha1 ~]# systemctl status keepalived

[root@mha1 ~]# systemctl enable keepalived

6.6模拟故障

关闭mha1的主节点

mha1：

[root@mha1 ~]# systemctl stop mysqld3310

[1]+  Done                    nohup masterha_manager --conf=/etc/mha_master/mha.cnf --remove_dead_master --ignore_last_failover < /dev/null > /etc/mha_master/manager.log 2>&1

查看集群状态

[root@mha1 /etc/keepalived]# masterha_check_repl -conf=/etc/mha_master/mha.cnf

mha2：

mysql> show slave status\G;

Empty set (0.00 sec)

ERROR:

No query specified

mysql> show master status;

+------------------+----------+--------------+------------------+------------------------------------------------------------------------------------+

| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                                                                  |

+------------------+----------+--------------+------------------+------------------------------------------------------------------------------------+

| mysql-bin.000002 |      234 |              |                  | b883ad36-731c-11eb-8f2b-000c297b5e9b:1-3,

d85d6dce-7287-11eb-9701-000c2902c557:1-8 |

+------------------+----------+--------------+------------------+------------------------------------------------------------------------------------+

1 row in set (0.00 sec)

mysql> show processlist;

+----+-------+----------------------+------+------------------+------+---------------------------------------------------------------+------------------+

| Id | User  | Host                 | db   | Command          | Time | State                                                         | Info             |

+----+-------+----------------------+------+------------------+------+---------------------------------------------------------------+------------------+

| 11 | slave | 192.168.163.20:58982 | NULL | Binlog Dump GTID |  598 | Master has sent all binlog to slave; waiting for more updates | NULL             |

| 15 | root  | localhost            | NULL | Query            |    0 | starting                                                      | show processlist |

+----+-------+----------------------+------+------------------+------+---------------------------------------------------------------+------------------+

2 rows in set (0.00 sec)

mha3：

mysql> show slave status\G;

6.7恢复故障节点

要先恢复mha1和mha2的主从关系，此时mha2是主库，mha1作为一个备库来恢复

mha2：

mha1：

mysql> change master to master_host='192.168.163.16',master_user='slave',master_port=3310,master_password='123',master_log_file='master-log.000002',master_log_pos=234;

Query OK, 0 rows affected, 2 warnings (0.01 sec)

mysql> stop slave;

Query OK, 0 rows affected (0.00 sec)

mysql> reset slave;

Query OK, 0 rows affected (0.01 sec)

mysql> start slave;

Query OK, 0 rows affected (0.01 sec)

mysql> show slave status\G;

检查集群状态，发现活着的节点并没有mha1

[root@mha1 /etc/keepalived]# masterha_check_repl -conf=/etc/mha_master/mha.cnf

此时需要重新添加mha1进配置文件，mha1已经被集群剔除，需要重新添加。mha1打开的一个过程是需要读取配置文件的，现在mha1已经不在控制文件里，需要手动添加一下

[server1]

candidate_master=1

hostname=192.168.163.3

port=3310

ssh_port=22

重新启动

[root@mha1 /etc/keepalived]# nohup masterha_manager --conf=/etc/mha_master/mha.cnf  --remove_dead_master --ignore_last_failover < /dev/null > /etc/mha_master/manager.log 2>&1 &

[1] 5023

6.8重新检查集群状态

[root@mha1 /etc/keepalived]# masterha_check_status --conf=/etc/mha_master/mha.cnf