docker + mysql 双主互备
环境 centos7、docker
| 10.200.132.168 | master | 3307 |
| 10.200.132.168 | slave | 3308 |
我使用的是以前自带的docker环境，mysql是docker images里面存在的镜像，也可以自行下载
1、脚本
vim /opt/bin/start-mysql-master.sh
docker run -d --restart=always --privileged=true --name=mysql-master -p 3307:3306 -e MYSQL_ROOT_PASSWORD=Pioneer@2017 -v /opt/data/mysql/data:/var/lib/mysql:rw -v /etc/localtime:/etc/localtime -v /opt/data/mysql/mysqld.cnf:/etc/mysql/mysql.conf.d/mysqld.cnf mysql
vim /opt/bin/start-mysql-slave.sh
docker run -d --restart=always --privileged=true --name=mysql-slave -p 3308:3306 -e MYSQL_ROOT_PASSWORD=Pioneer@2017 -v /opt/data/mysql/data-slave:/var/lib/mysql:rw -v /etc/localtime:/etc/localtime -v /opt/data/mysql/mysqld-slave.cnf:/etc/mysql/mysql.conf.d/mysqld.cnf mysql
配置可执行权限
chmod +x /opt/bin/start-mysql-master.sh
chmod +x /opt/bin/start-mysql-slave.sh
2、mysql data映射出来(/opt/data/mysql)
其中：
master data 目录：/opt/data/mysql/data
slave data 目录：/opt/data/mysql/data-slave
3、配置
master mysqld.cnf配置
[mysql]
[mysqld]
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
datadir = /var/lib/mysql
#log-error = /var/log/mysql/error.log
# By default we only accept connections from localhost
#bind-address = 127.0.0.1
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
lower_case_table_names = 1 #不区分大小写
character_set_server = utf8 #字符编码
log-bin=mysql-bin # 开启bin-log 日志，MySQL主从配置，必须开启
log-bin-index=mysql-bin
server_id=1 # 唯一的标识，与slave不同
log-slave-updates = true # 双主互备必须开启，否则只是主从关系
relay-log= relaylog
relay-log-index=relaylog
relay-log-purge=on
binlog-do-db=dcmp #开启同步的数据库
binlog-do-db=test
slave mysqld-slave.cnf
[mysql]
[mysqld]
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
datadir = /var/lib/mysql
#log-error = /var/log/mysql/error.log
# By default we only accept connections from localhost
#bind-address = 127.0.0.1
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
lower_case_table_names = 1 #不区分大小写
character_set_server = utf8 #字符编码
log-bin=mysql-bin # 开启bin-log 日志，MySQL主从配置，必须开启
log-bin-index=mysql-bin
server_id=2 # 唯一的标识，与master不同
log-slave-updates = true # 双主互备必须开启，否则只是主从关系
relay-log= relaylog
relay-log-index=relaylog
relay-log-purge=on
binlog-do-db=dcmp #开启同步的数据库
binlog-do-db=test
4、启动MySQL
执行第一步的脚本。
5、开启slave
①登陆master
docker exec -it mysql-master mysql -hlocalhost -uroot -p123456查看master status
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000007 | 154 | dcmp,test | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
②登陆slave
docker exec -it mysql-slave mysql -hlocalhost -uroot -p123456开启slave
mysql> change master to master_host='10.200.132.168',master_user='root',master_password='123456',master_port=3307, master_log_file='mysql-bin.000007',master_log_pos=154;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.200.132.168
Master_User: root
Master_Port: 3307
Connect_Retry: 60
Master_Log_File: mysql-bin.000007
Read_Master_Log_Pos: 154
Relay_Log_File: relaylog.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000007
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: 154
Relay_Log_Space: 520
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: 7beb7135-3ec4-11e7-b73a-0242ac110003
Master_Info_File: /var/lib/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:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
ERROR:
No query specified
change master to master_host='10.200.132.168',master_user='root',master_password='123456',master_port=3307, master_log_file='mysql-bin.000007',master_log_pos=154;
配置主库的信息，日志文件同步起始位。
start slave ： 开启slave
show slave status\G; 查看slave的同步情况，重点关注两个指标 Slave_IO_Running: 、 Slave_SQL_Running，如果都是yes，代表同步ok，否则任意一个为No,都是异常。
修改master 数据库test表，看看slave是否同步。
6、互备
以上只是开启单向同步的，即把master的数据同步到slave。适合读写分离机制
把slave 的数据同步到master跟上面配置基本一样。
①登陆slave
查看slave 的master
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000006 | 1948 | dcmp,test | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
②登陆master，开启master的slave
mysql> change master to master_host='10.200.132.168',master_user='root',master_password='123456',master_port=3308, master_log_file='mysql-bin.000006',master_log_pos=1948;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.200.132.168
Master_User: root
Master_Port: 3308
Connect_Retry: 60
Master_Log_File: mysql-bin.000006
Read_Master_Log_Pos: 1948
Relay_Log_File: relaylog.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000006
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: 1948
Relay_Log_Space: 520
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: 0e1fd2f7-a02e-11e8-a7ca-0242ac110007
Master_Info_File: /var/lib/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:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
ERROR:
No query specified
修改slave 的test库表数据，看看master是否有更新。
7、常见异常处理
①Fatal error : The slave I/O thread stops because master and slave have equal MySql server UUIDs
通过上面的报错信息我们其实就可以看出问题出在哪里。上面报错说的是replication架构中需要保证每个mysql实例UUID(UUID保存在datadir目录下的auto.cnf文件中)唯一，就跟server_id一样需要保证主从架构中所有mysql实例server_id唯一。
之所以出现会出现这样的问题，是因为我的从库主机是克隆的主库所在的主机，所以auto.cnf文件中保存的UUID会出现重复(server_id已经在my.cnf文件中修改过)
解决方案：
关于该问题的解决方案其实很简单，停掉备库实例，删除备库的auto.cnf文件，启动备库实例，此时备库就会产生一个新的auto.cnf文件(产生新的UUID)。
②ERROR 1872 (HY000): Slave failed to initialize relay log info structure from the repository
通过上面的报错以及relay log介绍，很容易知道由于mysql.slave_relay_log_info表中保留了以前的复制信息，导致新从库启动时无法找到对应文件，那么我们清理掉该表中的记录不就可以了。再次提醒，不要手动删该表数据，MySQL已经提供工具给我们了：reset slave：
reset slave干的那些事：
1、删除slave_master_info ，slave_relay_log_info两个表中数据；
2、删除所有relay log文件，并重新创建新的relay log文件；
3、不会改变gtid_executed 或者 gtid_purged的值下面解决问题：
| 1 2 |
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| 1 |
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| 1 2 |
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到这里问题解决了。
参考博客：https://www.cnblogs.com/mysql-dba/p/7201513.html
③Got fatal error 1236 from master when reading data from binary log: 'Could not open log file'
在master 方 flush logs
mysql> flush logs;
Query OK, 0 rows affected (0.01 sec)
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000003 | 154 | dcmp,test | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
在slave执行
mysql> reset slave;
Query OK, 0 rows affected (0.01 sec)
mysql> change master to master_host='10.200.132.168',master_user='root',master_password='123456',master_port=3308, master_log_file='mysql-bin.000003',master_log_pos=154;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)