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数据库中load data语句怎么保全主备复制数据一致性

发布时间:2022-01-12 11:05:33 所属栏目:MySql教程 来源:互联网
导读:小编给大家分享一下数据库中load data语句怎么保证主备复制数据一致性,希望大家阅读完这篇文章之后都有所收获,下面让我们一起去探讨吧! 背景 机器配置 * CPU:16 vcpus * 磁盘:100G flash卡 databinlog混用 * 内存:64G 数据库版本:MySQL 5.7.18 数据
数据库中load data语句怎么保全主备复制数据一致性
      小编给大家分享一下数据库中load data语句怎么保证主备复制数据一致性,希望大家阅读完这篇文章之后都有所收获,下面让我们一起去探讨吧!
 
      背景
     机器配置
* CPU:16 vcpus
* 磁盘:100G flash卡 data&binlog混用
* 内存:64G
数据库版本:MySQL 5.7.18
数据库IP信息:主库IP 10.10.30.241,从库IP 10.10.30.250
数据库参数配置:
* 主库:双一,log_slave_updates,log-bin,secure_file_priv='',server-id=3306241,binlog_rows_query_log_events=ON,sql_mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
* 从库:双一,log_slave_updates,log-bin,binlog_rows_query_log_events=ON,server-id=3306250,sql_mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
测试目的:通过示例演示并查看过程中binlog中如何记录load data语句等方式来验证 load data语句如何保证主备复制数据一致性
* 将分别在四种隔离级别下(会话级别修改tx_isolation)针对binlog_format(会话级别修改binlog_format)的三种格式分别进行演示执行load data语句,观察MySQL server层如何处理,主库binlog中如何记录load data语句,备库的binlog中如何如何记录load data语句
* 本文假定你已经搭建好了主备复制环境,如果未搭建请先自行搭建主备复制环境
PS:本文仅针对测试目的做验证演示,关于binlog_format三种格式以及事务的四种隔离级别详细说明请查阅相关资料,本文不做解读
* binlog_format参考资料:https://dev.mysql.com/doc/refman/5.7/en/replication-formats.html
* 事务隔离级别参考资料:https://dev.mysql.com/doc/refman/5.7/en/innodb-transaction-isolation-levels.html
1、制造测试数据
建库
admin@localhost : (none) 07:34:39> create database if not exists xiaoboluo;  

Query OK, 1 row affected (0.00 sec)
建表
admin@localhost : (none) 10:04:52> use xiaoboluo  

Database changed
admin@localhost : xiaoboluo 10:04:57> create table if not exists test_load(id int unsigned not null primary key auto_increment,test varchar(100));

Query OK, 0 rows affected (0.01 sec)
插入测试数据
admin@localhost : xiaoboluo 10:05:32> insert into test_load(test) values('1'),('2'),('null'),('4');  

Query OK, 4 rows affected (0.01 sec)

Records: 4 Duplicates: 0 Warnings: 0
 
 
admin@localhost : xiaoboluo 10:06:01> select * from test_load;
+----+------+
| id | test |
+----+------+
| 2 | 1 |
| 4 | 2 |
| 6 | null |
| 8 | 4 |
+----+------+

4 rows in set (0.00 sec)
执行select …into outifile语句生成load data需要的数据文本文件
admin@localhost : xiaoboluo 10:12:41> select * from test_load into outfile "/tmp/test_load.txt";  

Query OK, 4 rows affected (0.01 sec)

 
 
admin@localhost : xiaoboluo 10:12:42> system cat /tmp/test_load.txt;

2 1
4 2
6 null
8 4
2、read-uncommitted隔离级别
2.1. binlog_format=statement
先在主库中把binlog_format修改为statement,隔离级别修改为read-uncommitted,并刷新主从库binlog
# 主库  

admin@localhost : xiaoboluo 09:37:09> set binlog_format=statement;

Query OK, 0 rows affected (0.00 sec)

 
 
admin@localhost : xiaoboluo 09:39:24> set tx_isolation='read-uncommitted';

Query OK, 0 rows affected (0.00 sec)

 
 
admin@localhost : xiaoboluo 09:39:44> flush binary logs;

Query OK, 0 rows affected (0.01 sec)

 
 
# 从库
mysql> flush binary logs;

Query OK, 0 rows affected (0.01 sec)

 
 
mysql>
主库清空表test_load并执行load data语句
admin@localhost : xiaoboluo 09:39:54> truncate test_load;  

Query OK, 0 rows affected (0.00 sec)

admin@localhost : xiaoboluo 09:41:13> load data infile '/tmp/test_load.txt' into table test_load;

ERROR 1665 (HY000): Cannot execute statement: impossible to write to binary log since BINLOG_FORMAT = STATEMENT and at least one table uses a storage engine limited to row-based logging. InnoDB is limited to row-logging when transaction isolation level is READ COMMITTED or READ UNCOMMITTED.

Error (Code 1665): Cannot execute statement: impossible to write to binary log since BINLOG_FORMAT = STATEMENT and at least one table uses a storage engine limited to row-based logging. InnoDB is limited to row-logging when transaction isolation level is READ COMMITTED or READ UNCOMMITTED.

Error (Code 1015): Can
从以上结果中可以看到,在RU隔离级别下,binlog_format设置为statement不允许load data语句执行,从报错信息上可以看到,在RC和RU隔离级别下,binlog只能以row格式记录,所以statement无法记录binlog
查看主库表test_load中的数据
admin@localhost : xiaoboluo 09:41:52> select * from test_load;  

Empty set (0.00 sec)
从以上结果中可以看到,表数据并没有导入成功,现在解析binlog查看一下
[root@5f1772e3-0c7a-4537-97f9-9b57cf6a04c2 binlog]# ll  

total 196 -rw-r----- 1 mysql mysql 4916 May 4 00:11 mysql-bin.000014
  -rw-r----- 1 mysql mysql 4557 May 4 00:12 mysql-bin.000015 -rw-r----- 1 mysql mysql 5595 May 4 09:39 mysql-bin.000016 -rw-r----- 1 mysql mysql 366 May 4 09:41 mysql-bin.000017 -rw-r----- 1 mysql mysql 884 May 4 09:39 mysql-bin.index [root@5f1772e3-0c7a-4537-97f9-9b57cf6a04c2 binlog]# mysqlbinlog -vvv --base64-output=decode-rows mysql-bin.000017 ......

use `xiaoboluo`/*!*/;
......

truncate test_load
/*!*/;

SET @@SESSION.GTID_NEXT= 'AUTOMATIC' /* added by mysqlbinlog */ /*!*/;

DELIMITER ;

# End of log file ......
从上面的结果中可以看到,解析binlog的结果中除了use db和truncate table语句之外,没有其他的操作了,说明并没有数据写入,load data语句被mysql server直接拒绝执行了
2.2. binlog_format=mixed
先在主库中把binlog_format修改为mixed,隔离级别不要动,并刷新主从库binlog
# 主库  

admin@localhost : xiaoboluo 09:44:05> set binlog_format=mixed;

Query OK, 0 rows affected (0.00 sec)

 
 
admin@localhost : xiaoboluo 09:49:49> flush binary logs;

Query OK, 0 rows affected (0.01 sec)

 
 
# 从库
mysql> flush binary logs;

Query OK, 0 rows affected (0.01 sec)

 
 
mysql>
主库清空表test_load并执行load data语句
admin@localhost : xiaoboluo 09:49:57> truncate test_load;  

Query OK, 0 rows affected (0.01 sec)

 
 
admin@localhost : xiaoboluo 09:51:12> load data infile '/tmp/test_load.txt' into table test_load;

Query OK, 4 rows affected (0.00 sec)

Records: 4 Deleted: 0 Skipped: 0 Warnings: 0
从以上结果中可以看到,在RU隔离级别下,binlog_format设置为mixed允许load data语句执行
查看主库表test_load中的数据
admin@localhost : xiaoboluo 09:51:24> select * from test_load;  
+----+------+
| id | test |
+----+------+
| 2 | 1 |
| 4 | 2 |
| 6 | null |
| 8 | 4 |
+----+------+

4 rows in set (0.00 sec)
从以上结果中可以看到,表数据导入成功,现在解析binlog查看一下
[root@5f1772e3-0c7a-4537-97f9-9b57cf6a04c2 binlog]# ll  

total 196 -rw-r----- 1 mysql mysql 4916 May 4 00:11 mysql-bin.000014 -rw-r----- 1 mysql mysql 4557 May 4 00:12 mysql-bin.000015 -rw-r----- 1 mysql mysql 5595 May 4 09:39 mysql-bin.000016 -rw-r----- 1 mysql mysql 366 May 4 09:41 mysql-bin.000017 -rw-r----- 1 mysql mysql 744 May 4 09:51 mysql-bin.000018 -rw-r----- 1 mysql mysql 936 May 4 09:49 mysql-bin.index [root@5f1772e3-0c7a-4537-97f9-9b57cf6a04c2 binlog]# mysqlbinlog -vv --base64-output=decode-rows mysql-bin.000018
# at 259
#170504  9:51:12 server id 3306241  end_log_pos 354 CRC32 0xff83f0ce Query thread_id=155 exec_time=0 error_code=0
use `xiaoboluo`/*!*/;
......

truncate test_load ......

BEGIN
/*!*/;

# at 501
#170504  9:51:24 server id 3306241  end_log_pos 583 CRC32 0xfef1767a Rows_query
# load data infile '/tmp/test_load.txt' into table test_load  # 这里可以看到load data语句在这里,这里是开启了参数binlog_rows_query_log_events=ON之后记录的原生sql,默认被加了注释,主备复制不会执行
# at 583
#170504  9:51:24 server id 3306241  end_log_pos 643 CRC32 0x349b62a4 Table_map: `xiaoboluo`.`test_load` mapped to number 340
# at 643
#170504  9:51:24 server id 3306241  end_log_pos 713 CRC32 0x4ceacc10 Write_rows: table id 340 flags: STMT_END_F
### INSERT INTO `xiaoboluo`.`test_load`  #这里是用于主备复制的数据变更日志,可以看到在mixed格式下被转换为了row格式
### SET
###   @1=2 /* INT meta=0 nullable=0 is_null=0 */

###   @2='1' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

### INSERT INTO `xiaoboluo`.`test_load`
### SET
###   @1=4 /* INT meta=0 nullable=0 is_null=0 */

###   @2='2' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

### INSERT INTO `xiaoboluo`.`test_load`
### SET
###   @1=6 /* INT meta=0 nullable=0 is_null=0 */

###   @2='null' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

### INSERT INTO `xiaoboluo`.`test_load`
### SET
###   @1=8 /* INT meta=0 nullable=0 is_null=0 */

###   @2='4' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

# at 713
#170504  9:51:24 server id 3306241  end_log_pos 744 CRC32 0xfa76965b Xid = 1237
COMMIT/*!*/;

SET @@SESSION.GTID_NEXT= 'AUTOMATIC' /* added by mysqlbinlog */ /*!*/;

DELIMITER ;

# End of log file
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;

/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/
从上面解析binlog的结果中可以看到,数据写入成功,load data语句被转换为row格式记录在binlog中
查看备库中数据是否正确复制
mysql> use xiaoboluo  

Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
 
 
Database changed
mysql> select * from test_load;
+----+------+
| id | test |
+----+------+
| 2 | 1 |
| 4 | 2 |
| 6 | null |
| 8 | 4 |
+----+------+

4 rows in set (0.00 sec)
解析备库binlog中是如何记录的load data语句
[root@e710d318-d5b4-4bc7-a606-d09f06ff5f5d binlog]# ll  

total 100 -rw-r----- 1 mysql mysql 990 May 1 01:36 mysql-bin.000001 -rw-r----- 1 mysql mysql 54766 May 4 00:02 mysql-bin.000002 -rw-r----- 1 mysql mysql 21376 May 4 09:40 mysql-bin.000003 -rw-r----- 1 mysql mysql 401 May 4 09:50 mysql-bin.000004 -rw-r----- 1 mysql mysql 730 May 4 09:51 mysql-bin.000005 -rw-r----- 1 mysql mysql 260 May 4 09:50 mysql-bin.index [root@e710d318-d5b4-4bc7-a606-d09f06ff5f5d binlog]# mysqlbinlog -vv --base64-output=decode-rows mysql-bin.000005 ...

#170504  9:51:12 server id 3306241  end_log_pos 354 CRC32 0xff83f0ce Query thread_id=155 exec_time=0 error_code=0
use `xiaoboluo`/*!*/;
...

truncate test_load ...

BEGIN
/*!*/;

# at 487
#170504  9:51:24 server id 3306241  end_log_pos 569 CRC32 0x67a31998 Rows_query
# load data infile '/tmp/test_load.txt' into table test_load  # 这里可以看到load data语句在这里,这里是开启了参数binlog_rows_query_log_events=ON之后记录的原生sql,默认被加了注释,主备复制不会执行
# at 569
#170504  9:51:24 server id 3306241  end_log_pos 629 CRC32 0x6420d19b Table_map: `xiaoboluo`.`test_load` mapped to number 301
# at 629
#170504  9:51:24 server id 3306241  end_log_pos 699 CRC32 0xf5fff0d8 Write_rows: table id 301 flags: STMT_END_F
### INSERT INTO `xiaoboluo`.`test_load`  #这里是备库记录的主库binlog日志,可以看到在mixed格式下被转换为了row格式
### SET
###   @1=2 /* INT meta=0 nullable=0 is_null=0 */

###   @2='1' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

### INSERT INTO `xiaoboluo`.`test_load`
### SET
###   @1=4 /* INT meta=0 nullable=0 is_null=0 */

###   @2='2' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

### INSERT INTO `xiaoboluo`.`test_load`
### SET
###   @1=6 /* INT meta=0 nullable=0 is_null=0 */

###   @2='null' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

### INSERT INTO `xiaoboluo`.`test_load`
### SET
###   @1=8 /* INT meta=0 nullable=0 is_null=0 */

###   @2='4' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

# at 699
#170504  9:51:24 server id 3306241  end_log_pos 730 CRC32 0xd5a3bda4 Xid = 424
COMMIT/*!*/;
...
2.3. binlog_format=row
先在主库中把binlog_format修改为row,隔离级别不要动,并刷新主从库binlog
# 主库  

admin@localhost : xiaoboluo 11:05:20> set binlog_format=row;

Query OK, 0 rows affected (0.00 sec)

admin@localhost : xiaoboluo 11:18:23> flush binary logs;

Query OK, 0 rows affected (0.01 sec)

# 从库
mysql> flush binary logs;

Query OK, 0 rows affected (0.01 sec)

mysql>
主库清空表test_load并执行load data语句
admin@localhost : xiaoboluo 11:18:26> truncate test_load;  

Query OK, 0 rows affected (0.01 sec)

admin@localhost : xiaoboluo 11:18:51> load data infile '/tmp/test_load.txt' into table test_load;

Query OK, 4 rows affected (0.00 sec)

Records: 4 Deleted: 0 Skipped: 0 Warnings: 0
从以上结果中可以看到,在RU隔离级别下,binlog_format设置为row允许load data语句执行
查看主库表test_load中的数据
admin@localhost : xiaoboluo 11:18:57> select * from test_load;  
+----+------+
| id | test |
+----+------+
| 2 | 1 |
| 4 | 2 |
| 6 | null |
| 8 | 4 |
+----+------+

4 rows in set (0.00 sec)
从以上结果中可以看到,表数据导入成功,现在解析binlog查看一下
[root@5f1772e3-0c7a-4537-97f9-9b57cf6a04c2 binlog]# ll  

total 196 -rw-r----- 1 mysql mysql 4916 May 4 00:11 mysql-bin.000014 -rw-r----- 1 mysql mysql 4557 May 4 00:12 mysql-bin.000015 -rw-r----- 1 mysql mysql 5595 May 4 09:39 mysql-bin.000016 -rw-r----- 1 mysql mysql 366 May 4 09:41 mysql-bin.000017 -rw-r----- 1 mysql mysql 744 May 4 09:51 mysql-bin.000018 -rw-r----- 1 mysql mysql 744 May 4 11:18 mysql-bin.000019 -rw-r----- 1 mysql mysql 988 May 4 11:18 mysql-bin.index [root@5f1772e3-0c7a-4537-97f9-9b57cf6a04c2 binlog]# mysqlbinlog -vv --base64-output=decode-rows mysql-bin.000018
# at 259
#170504 11:18:51 server id 3306241  end_log_pos 354 CRC32 0x9d5985ad Query thread_id=155 exec_time=0 error_code=0
use `xiaoboluo`/*!*/;
......

truncate test_load ......

BEGIN
/*!*/;

# at 501
#170504 11:18:57 server id 3306241  end_log_pos 583 CRC32 0x0e8f7603 Rows_query
# load data infile '/tmp/test_load.txt' into table test_load # 这里可以看到load data语句在这里,这里是开启了参数binlog_rows_query_log_events=ON之后记录的原生sql,默认被加了注释,主备复制不会执行
# at 583
#170504 11:18:57 server id 3306241  end_log_pos 643 CRC32 0xe1c5d4d0 Table_map: `xiaoboluo`.`test_load` mapped to number 341
# at 643
#170504 11:18:57 server id 3306241  end_log_pos 713 CRC32 0x31619df3 Write_rows: table id 341 flags: STMT_END_F
### INSERT INTO `xiaoboluo`.`test_load`   #这里是用于主备复制的数据变更日志,可以看到在row格式下被转换为了row格式
### SET
###   @1=2 /* INT meta=0 nullable=0 is_null=0 */

###   @2='1' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

### INSERT INTO `xiaoboluo`.`test_load`
### SET
###   @1=4 /* INT meta=0 nullable=0 is_null=0 */

###   @2='2' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

### INSERT INTO `xiaoboluo`.`test_load`
### SET
###   @1=6 /* INT meta=0 nullable=0 is_null=0 */

###   @2='null' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

### INSERT INTO `xiaoboluo`.`test_load`
### SET
###   @1=8 /* INT meta=0 nullable=0 is_null=0 */

###   @2='4' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */

# at 713
#170504 11:18:57 server id 3306241  end_log_pos 744 CRC32 0x18b14b52 Xid = 1245
COMMIT/*!*/;
......
从上面解析binlog的结果中可以看到,数据写入成功,load data语句被转换为row格式记录在binlog中
查看备库中数据是否正确复制
[root@5f1772e3-0c7a-4537-97f9-9b57cf6a04c2 binlog]# ll  

total 196 -rw-r----- 1 mysql mysql 4916 May 4 00:11 mysql-bin.000014
  -rw-r----- 1 mysql mysql 4557 May 4 00:12 mysql-bin.000015 -rw-r----- 1 mysql mysql 5595 May 4 09:39 mysql-bin.000016 -rw-r----- 1 mysql mysql 366 May 4 09:41 mysql-bin.000017 -rw-r----- 1 mysql mysql 744 May 4 09:51 mysql-bin.000018
  -rw-r----- 1 mysql mysql 744 May 4 11:18 mysql-bin.000019 -rw-r----- 1 mysql mysql 988 May 4 11:18 mysql-bin.index
 
  [root@5f1772e3-0c7a-4537-97f9-9b57cf6a04c2 binlog]# mysqlbinlog -vv --base64-output=decode-rows mysql-bin.000018
# at 259
#170504 11:18:51 server id 3306241  end_log_pos 354 CRC32 0

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