MySQL主从复制

MySQL

1. 主数据库配置

[mysqld]
server-id = 1        # 节点ID，确保唯一

# log config
log-bin = mysql-bin     #开启mysql的binlog日志功能
sync_binlog = 1         #控制数据库的binlog刷到磁盘上去 , 0 不控制，性能最好，1每次事物提交都会刷到日志文件中，性能最差，最安全
binlog_format = mixed   #binlog日志格式，mysql默认采用statement，建议使用mixed
expire_logs_days = 7                           #binlog过期清理时间
max_binlog_size = 100m                    #binlog每个日志文件大小
binlog_cache_size = 4m                        #binlog缓存大小
max_binlog_cache_size= 512m              #最大binlog缓存大
binlog-ignore-db=mysql #不生成日志文件的数据库，多个忽略数据库可以用逗号拼接，或者 复制这句话，写多行

auto-increment-offset = 1     # 自增值的偏移量
auto-increment-increment = 1  # 自增值的自增量
slave-skip-errors = all #跳过从库错误

2. 从数据库配置加入

server-id=2
relay-log=slave-relay-bin
relay-log-index=slave-relay-bin.index
#replicate-do-db=test
#备注：
#server-id 服务器唯一标识，如果有多个从服务器，每个服务器的server-id不能重复，跟IP一样是唯一标识，如果你没设置server-id或者设置为0，则从服务器不会连接到主服务器。
#relay-log 启动MySQL二进制日志，可以用来做数据备份和崩溃恢复，或主服务器挂掉了，将此从服务器作为其他从服务器的主服务器。
#replicate-do-db 指定同步的数据库，如果复制多个数据库，重复设置这个选项即可。若在master端不指定binlog-do-db，则在slave端可用replication-do-db来过滤。
#replicate-ignore-db 不需要同步的数据库，如果有多个数据库，重复设置这个选项即可。

3. 重启主和从数据库

service mysql restart

4. 主数据库查看master状态

show master status

MariaDB [(none)]> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000005      120|              | mysql            |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

5. 从数据库进入mysql配置

MariaDB [(none)]> CHANGE MASTER TO 
MASTER_HOST = '172.17.0.3',  
MASTER_USER = 'repl_user', 
MASTER_PASSWORD = 'repl_passwd',
MASTER_PORT = 3307,
MASTER_LOG_FILE='mysql-bin.000005',
MASTER_LOG_POS=120,
MASTER_RETRY_COUNT = 60,
MASTER_HEARTBEAT_PERIOD = 10000; 
# MASTER_USER = 'repl_user', # 主库的账号
# MASTER_PASSWORD = 'repl_passwd', # 主库的密码
# MASTER_LOG_FILE='mysql-bin.000005',#与主库File 保持一致
# MASTER_LOG_POS=120 , #与主库Position 保持一致

6. 从数据库开启slave进程

MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.002 sec)

7. 查看同步状态

MariaDB [(none)]> show slave status\G;
*************************** 1. row ***************************
                Slave_IO_State: Waiting for master to send event
                   Master_Host: 120.78.176.77
                   Master_User: root
                   Master_Port: 3306
                 Connect_Retry: 60
               Master_Log_File: mysql-bin.000002
           Read_Master_Log_Pos: 154
                Relay_Log_File: PC-202008301542-relay-bin.000002
                 Relay_Log_Pos: 422
         Relay_Master_Log_File: mysql-bin.000002
              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: 741
               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_SSL_Crl:
            Master_SSL_Crlpath:
                    Using_Gtid: No
                   Gtid_IO_Pos:
       Replicate_Do_Domain_Ids:
   Replicate_Ignore_Domain_Ids:
                 Parallel_Mode: optimistic
                     SQL_Delay: 0
           SQL_Remaining_Delay: NULL
       Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
              Slave_DDL_Groups: 0
Slave_Non_Transactional_Groups: 0
    Slave_Transactional_Groups: 0
1 row in set (0.000 sec)

# 出现这两个说明同步成功
# Slave_IO_Running: Yes
# Slave_SQL_Running: Yes

问题

ERROR 1201 (HY000): Could not initialize master info structure for ''; more error messages can be found in the MariaDB error log

如果在操作到遇到上面问题的报错，就执行下面这句， 继续从第5步开始

MariaDB [(none)]> reset slave;
Query OK, 0 rows affected (0.037 sec)