• MySQL主从环境下存储过程,函数,触发器,事件的复制情况


    下面,主要是验证在MySQL主从复制环境下,存储过程,函数,触发器,事件的复制情况,这些确实会让人混淆。

    首先,创建一张测试表

    mysql> create table test.t1(name varchar(10),age int);
    Query OK, 0 rows affected (0.10 sec)

    存储过程

    创建存储过程

    delimiter //
    CREATE procedure p1 (IN name varchar(10),IN age int)
     BEGIN
     insert into test.t1 values(name,age);
    END//
    delimiter ;

    通过查看二进制日志,可以看到该DDL语句已被记录

    # at 120
    #161010 23:18:38 server id 1  end_log_pos 339 CRC32 0xae3dcfda     Query    thread_id=2    exec_time=0    error_code=0
    use `test`/*!*/;
    SET TIMESTAMP=1476112718/*!*/;
    SET @@session.pseudo_thread_id=2/*!*/;
    SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
    SET @@session.sql_mode=1075838976/*!*/;
    SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
    /*!C utf8 *//*!*/;
    SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=33/*!*/;
    SET @@session.lc_time_names=0/*!*/;
    SET @@session.collation_database=DEFAULT/*!*/;
    CREATE DEFINER=`root`@`localhost` PROCEDURE `p1`(IN name varchar(10),IN age int)
    BEGIN
     insert into test.t1 values(name,age);
    END
    /*!*/;
    DELIMITER ;

    执行存储过程

    mysql> call p1('tom',10);
    Query OK, 1 row affected (0.08 sec)
    
    mysql> select * from t1;
    +-------+------+
    | name  | age  |
    +-------+------+
    | tom   |   10 |
    +-------+------+
    1 rows in set (0.01 sec)

    查看二进制日志中,记录的是还是call p1('tom',10)操作记录对应的SQL语句

    # at 574
    #161010 23:23:54 server id 1  end_log_pos 653 CRC32 0xc532cfae     Query    thread_id=2    exec_time=0    error_code=0
    SET TIMESTAMP=1476113034/*!*/;
    BEGIN
    /*!*/;
    # at 653
    #161010 23:23:54 server id 1  end_log_pos 833 CRC32 0x2982c7a8     Query    thread_id=2    exec_time=0    error_code=0
    SET TIMESTAMP=1476113034/*!*/;
    insert into test.t1 values( NAME_CONST('name',_utf8'tom' COLLATE 'utf8_general_ci'), NAME_CONST('age',10))
    /*!*/;
    # at 833
    #161010 23:23:54 server id 1  end_log_pos 864 CRC32 0xdf106f41     Xid = 56
    COMMIT/*!*/;

    由此可见,对于存储过程,在主从复制中,记录的是存储过程对应的DML操作,而不是调用动作本身。

    函数

    创建函数

    CREATE FUNCTION f1 (string VARCHAR(5))
    RETURNS VARCHAR(20) DETERMINISTIC
    RETURN CONCAT('f1',string);

    二进制日志中的记录如下:

    # at 1246
    #161010 23:34:01 server id 1  end_log_pos 1480 CRC32 0x3a1eb0a2     Query    thread_id=2    exec_time=0    error_code=0
    SET TIMESTAMP=1476113641/*!*/;
    CREATE DEFINER=`root`@`localhost` FUNCTION `f1`(string VARCHAR(5)) RETURNS varchar(20) CHARSET utf8
        DETERMINISTIC
    RETURN CONCAT('f1',string)
    /*!*/;

    执行函数

    在这里,其实要分两种情况,一是binlog_format为statement,另一种情况为row

    当binlog_format为statement时

    mysql> show variables like '%binlog_format%';
    +---------------+-----------+
    | Variable_name | Value     |
    +---------------+-----------+
    | binlog_format | STATEMENT |
    +---------------+-----------+
    1 row in set (0.02 sec)
    
    mysql> insert into t1(name) values(f1('steve'));
    Query OK, 1 row affected (0.07 sec)
    
    mysql> select * from t1;
    +---------+------+
    | name    | age  |
    +---------+------+
    | tom     |   10 |
    | f1steve | NULL |
    +---------+------+
    2 rows in set (0.00 sec)

    查看该语句对应的二进制日志中的内容

    # at 1480
    #161010 23:37:58 server id 1  end_log_pos 1559 CRC32 0xf1f2c4a2     Query    thread_id=2    exec_time=0    error_code=0
    SET TIMESTAMP=1476113878/*!*/;
    BEGIN
    /*!*/;
    # at 1559
    #161010 23:37:58 server id 1  end_log_pos 1673 CRC32 0x0c9a73c5     Query    thread_id=2    exec_time=0    error_code=0
    SET TIMESTAMP=1476113878/*!*/;
    insert into t1(name) values(f1('steve'))
    /*!*/;
    # at 1673
    #161010 23:37:58 server id 1  end_log_pos 1704 CRC32 0x45419118     Xid = 67
    COMMIT/*!*/;

    可见在statement的二进制日志格式下,复制的调用函数这个操作本身。

    当binlog_format为row时

    mysql> set session binlog_format='row';
    Query OK, 0 rows affected (0.00 sec)
    
    mysql> insert into t1(name) values(f1('tiger'));
    Query OK, 1 row affected (0.03 sec)

    对应的二进制日志的内容

    # at 2139
    #161010 23:43:35 server id 1  end_log_pos 2211 CRC32 0x7c74abd9     Query    thread_id=2    exec_time=0    error_code=0
    SET TIMESTAMP=1476114215/*!*/;
    BEGIN
    /*!*/;
    # at 2211
    #161010 23:43:35 server id 1  end_log_pos 2259 CRC32 0x657ac7ac     Table_map: `test`.`t1` mapped to number 78
    # at 2259
    #161010 23:43:35 server id 1  end_log_pos 2303 CRC32 0x3f15b37c     Write_rows: table id 78 flags: STMT_END_F
    ### INSERT INTO `test`.`t1`
    ### SET
    ###   @1='f1tiger' /* VARSTRING(30) meta=30 nullable=1 is_null=0 */
    ###   @2=NULL /* VARSTRING(30) meta=0 nullable=1 is_null=1 */
    # at 2303
    #161010 23:43:35 server id 1  end_log_pos 2334 CRC32 0xe5acc4aa     Xid = 80
    COMMIT/*!*/;

    可见,在row格式下,复制的不是函数操作本身,而是函数对应的值。

    触发器

    首先,创建两张测试表

    CREATE TABLE test1(a1 INT);
    CREATE TABLE test2(a2 INT);

    创建触发器

    delimiter //
    CREATE TRIGGER t_test1 BEFORE INSERT ON test1
    FOR EACH ROW
    BEGIN
    INSERT INTO test2 SET a2 = NEW.a1;
    END;
    //
    delimiter ;

    二进制日志中的记录如下:

    # at 556
    #161011 10:46:52 server id 1  end_log_pos 776 CRC32 0xf065830f     Query    thread_id=4    exec_time=0    error_code=0
    SET TIMESTAMP=1476154012/*!*/;
    CREATE DEFINER=`root`@`localhost` TRIGGER t_test1 BEFORE INSERT ON test1
    FOR EACH ROW
    BEGIN
    INSERT INTO test2 SET a2 = NEW.a1;
    END
    /*!*/;

    测试触发器,向test1中添加一条记录

    在STATEMENT格式下

    mysql> insert into test1 values(1);
    Query OK, 1 row affected (0.07 sec)
    
    mysql> select * from test1;
    +------+
    | a1   |
    +------+
    |    1 |
    +------+
    1 row in set (0.01 sec)
    
    mysql> select * from test2;
    +------+
    | a2   |
    +------+
    |    1 |
    +------+
    1 row in set (0.00 sec)

    查看该语句对应的二进制日志中的内容

    # at 776
    #161011 10:49:37 server id 1  end_log_pos 855 CRC32 0x0d73131b     Query    thread_id=5    exec_time=0    error_code=0
    SET TIMESTAMP=1476154177/*!*/;
    BEGIN
    /*!*/;
    # at 855
    #161011 10:49:37 server id 1  end_log_pos 956 CRC32 0x6cf2e73c     Query    thread_id=5    exec_time=0    error_code=0
    SET TIMESTAMP=1476154177/*!*/;
    insert into test1 values(1)
    /*!*/;
    # at 956
    #161011 10:49:37 server id 1  end_log_pos 987 CRC32 0x98e3a631     Xid = 51
    COMMIT/*!*/;

    可见,对于触发器,主从均会触发,复制只需记录触发条件本身,在本例中,即“insert into test1 values(1)”,而不会记录所引发的触发操作,即“INSERT INTO test2 SET a2 = NEW.a1”。

    在ROW格式下

    mysql> set session binlog_format='row';
    Query OK, 0 rows affected (0.00 sec)
    
    mysql> insert into test1 values(2);
    Query OK, 1 row affected (0.06 sec)

    对应的二进制日志为:

    # at 399
    #161019 10:10:27 server id 1  end_log_pos 471 CRC32 0x667b6938     Query    thread_id=3    exec_time=0    error_code=0
    SET TIMESTAMP=1476843027/*!*/;
    BEGIN
    /*!*/;
    # at 471
    #161019 10:10:27 server id 1  end_log_pos 519 CRC32 0xccaee383     Table_map: `test`.`test1` mapped to number 85
    # at 519
    #161019 10:10:27 server id 1  end_log_pos 567 CRC32 0x9625b60f     Table_map: `test`.`test2` mapped to number 86
    # at 567
    #161019 10:10:27 server id 1  end_log_pos 607 CRC32 0x620381e3     Write_rows: table id 86
    # at 607
    #161019 10:10:27 server id 1  end_log_pos 647 CRC32 0xff82eb9d     Write_rows: table id 85 flags: STMT_END_F
    
    BINLOG '
    E9YGWBMBAAAAMAAAAAcCAAAAAFUAAAAAAAEABHRlc3QABXRlc3QxAAEDAAGD467M
    E9YGWBMBAAAAMAAAADcCAAAAAFYAAAAAAAEABHRlc3QABXRlc3QyAAEDAAEPtiWW
    E9YGWB4BAAAAKAAAAF8CAAAAAFYAAAAAAAAAAgAB//4CAAAA44EDYg==
    ### INSERT INTO `test`.`test2`
    ### SET
    ###   @1=2 /* INT meta=0 nullable=1 is_null=0 */
    E9YGWB4BAAAAKAAAAIcCAAAAAFUAAAAAAAEAAgAB//4CAAAAneuC/w==
    '/*!*/;
    ### INSERT INTO `test`.`test1`
    ### SET
    ###   @1=2 /* INT meta=0 nullable=1 is_null=0 */
    # at 647
    #161019 10:10:27 server id 1  end_log_pos 678 CRC32 0x5384a1bc     Xid = 87
    COMMIT/*!*/;

    可见,在row格式下,会同时复制触发操作本身,此时,无论是否删除slave上的触发器,主从数据仍保持一致。但是在statement的格式下,如果删除了slave上的触发器,则会导致主从数据不一致。

    EVENT

    创建EVENT

    CREATE EVENT e_test1
    ON SCHEDULE
    EVERY 10 SECOND
    DO
    INSERT INTO test.test1 VALUES (UNIX_TIMESTAMP());

    二进制日志中的记录如下:

    # at 987
    #161011 11:02:45 server id 1  end_log_pos 1218 CRC32 0x875a245e     Query    thread_id=5    exec_time=0    error_code=0
    SET TIMESTAMP=1476154965/*!*/;
    SET @@session.time_zone='SYSTEM'/*!*/;
    CREATE DEFINER=`root`@`localhost` EVENT e_test1
    ON SCHEDULE
    EVERY 10 SECOND
    DO
    INSERT INTO test.test1 VALUES (UNIX_TIMESTAMP())
    /*!*/;

    如果要让EVENT执行,必须将event_scheduler设置为ON,默认为OFF。

    mysql> set global event_scheduler=1;
    Query OK, 0 rows affected (0.09 sec)

    这时EVENT会执行,每10s向test1表中插入一条记录

    mysql> select * from test1;
    +------------+
    | a1         |
    +------------+
    |          1 |
    | 1476155165 |
    | 1476155175 |
    +------------+
    3 rows in set (0.01 sec)

    对应的二进制日志中的内容

    # at 1319
    #161011 11:06:05 server id 1  end_log_pos 1398 CRC32 0xcc4e1873     Query    thread_id=7    exec_time=0    error_code=0
    SET TIMESTAMP=1476155165/*!*/;
    SET @@session.sql_auto_is_null=1/*!*/;
    BEGIN
    /*!*/;
    # at 1398
    #161011 11:06:05 server id 1  end_log_pos 1520 CRC32 0x24ee06c6     Query    thread_id=7    exec_time=0    error_code=0
    SET TIMESTAMP=1476155165/*!*/;
    INSERT INTO test.test1 VALUES (UNIX_TIMESTAMP())
    /*!*/;
    # at 1520
    #161011 11:06:05 server id 1  end_log_pos 1551 CRC32 0xa3ed03fa     Xid = 65
    COMMIT/*!*/;

    可见,对于EVENT,只是复制EVENT语句。

    可能有人会疑问,slave上面是否同样会执行event呢?

    经测试证明,即使将slave上event_scheduler开启了,也不会导致slave上event的执行,即使执行了stop slave操作,该event同样不会执行。

    通过查看主从上的event状态,可以看出两者的不同

    Master

    mysql> show eventsG
    *************************** 1. row ***************************
                      Db: test
                    Name: e_test1
                 Definer: root@localhost
               Time zone: SYSTEM
                    Type: RECURRING
              Execute at: NULL
          Interval value: 10
          Interval field: SECOND
                  Starts: 2016-10-11 11:02:45
                    Ends: NULL
                  Status: ENABLED
              Originator: 1
    character_set_client: utf8
    collation_connection: utf8_general_ci
      Database Collation: utf8_general_ci
    1 row in set (0.00 sec)

    Slave

    mysql> show eventsG
    *************************** 1. row ***************************
                      Db: test
                    Name: e_test1
                 Definer: root@localhost
               Time zone: SYSTEM
                    Type: RECURRING
              Execute at: NULL
          Interval value: 10
          Interval field: SECOND
                  Starts: 2016-10-11 11:02:45
                    Ends: NULL
                  Status: SLAVESIDE_DISABLED
              Originator: 1
    character_set_client: utf8
    collation_connection: utf8_general_ci
      Database Collation: utf8_general_ci
    1 row in set (0.00 sec)

    可以看出,相同的event,master上的状态是ENABLED,而slave上的状态确是SLAVESIDE_DISABLED。

    如果要开启slave上面的event,可通过如下命令开启

    alter event test.e_test1 enable;

    经测试,直接update mysql.event没有效果。

    总结

    1. 对于存储过程,只是复制存储过程中定义的DML语句。

    2. 对于函数,在statement格式下,只是复制函数名,也就是说,函数在主从上同样会被执行。

    3. 对于触发器,在statement格式下,复制的只是触发条件,而不会是触发动作。也就是说,触发器在主从上同样会被运行。

        但是在row格式下,则不仅会复制触发条件,还会复制触发动作。

    4. 对于event,复制的也只是事件体中的DML语句。

    参考

    1. http://dev.mysql.com/doc/refman/5.7/en/create-procedure.html

    2. http://dev.mysql.com/doc/refman/5.7/en/create-trigger.html

    3. http://dev.mysql.com/doc/refman/5.7/en/create-event.html

  • 相关阅读:
    【VS2013编译DirectX Tutorials时遇到的错误】"const wchar_t *" 类型的实参与 "LPCSTR" 类型的形参不兼容
    python3 登录接口
    Python-网络编程
    Python之mock接口开发
    python基础笔记(五):操作excel、mysql、redis
    python基础笔记(六):md5加密
    python3基础笔记(四):模块安装&os模块&时间模块
    python3基础笔记(三):函数
    python3基础笔记(二):文件操作、json操作
    Python3基础笔记
  • 原文地址:https://www.cnblogs.com/ivictor/p/5947639.html
Copyright © 2020-2023  润新知