mysqldbcompare也是MySQL-Utilities工具集的一个脚本。mysqldbcompare从两个数据库比较对象和数据的不同。数据库中的对象包括：表、视图、触发器、存储过程、函数和事件。每一个对象类型计数可以使用-vv选项显示。通过一系列步骤检查进行测试，默认情况下，一旦测试失败就终止检测。可以指定--run-all-tests选项来进行所有的测试。
环境：CentOS6.5源码安装多个MySQL实例及复制搭建，之前做复制时Master实例的test库中的数据表没有复制到Slave实例
#使用Master中的test.test1的建表语句创建Slave中的test.test1，修改列c的说明，并插入数据 use test; create table test1 (id int not null primary key, a varchar(10) not null, b varchar(10), c varchar(10) comment 'cc', d int ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='test1'; insert into test1 values(1,'a','b','c',1);
此时两表的定义和数据是不一致的。
比较检测的步骤
1、数据库定义的检查 检查对比的数据库是否存在
[root@VMUest ~]# mysqldbcompare --server1=mydba:mysql5635@192.168.85.129:3306 --server2=mydba:mysql5635@192.168.85.129:3307 --changes-for=server2 --show-reverse --difftype=sql test:test1 # WARNING: Using a password on the command line interface can be insecure. # server1 on 192.168.85.129: ... connected. # server2 on 192.168.85.129: ... connected. ERROR: The database test1 does not exist.
2、检测数据库的对象 检查两者数据库中的对象是否丢失。可以使用--skip-object-compare选项跳过这步。
[root@VMUest ~]# mysqldbcompare --server1=mydba:mysql5635@192.168.85.129:3306 --server2=mydba:mysql5635@192.168.85.129:3307 --changes-for=server2 --show-reverse --difftype=sql test:test # WARNING: Using a password on the command line interface can be insecure. # server1 on 192.168.85.129: ... connected. # server2 on 192.168.85.129: ... connected. # Checking databases test on server1 and test on server2 # ERROR: The list of objects differs among database test and test.
3、比较对象的定义 对对象的定义（CREATE语句）进行比较和显示不同。可以使用--skip-diff选项跳过这步。
[root@VMUest ~]# mysqldbcompare --server1=mydba:mysql5635@192.168.85.129:3306 --server2=mydba:mysql5635@192.168.85.129:3307 --changes-for=server2 --show-reverse --difftype=sql test:test --skip-object-compare # WARNING: Using a password on the command line interface can be insecure. # server1 on 192.168.85.129: ... connected. # server2 on 192.168.85.129: ... connected. # Checking databases test on server1 and test on server2 # # Defn Row Data # Type Object Name Diff Count Check # ------------------------------------------------------------------------- # TABLE test1 FAIL ERROR: The object definitions do not match.
4、检测表的行数 检查表是否有相同的行数，但这并不确保表的数据是一致性的。可以使用--skip-row-count选项跳过这步。
[root@VMUest ~]# mysqldbcompare --server1=mydba:mysql5635@192.168.85.129:3306 --server2=mydba:mysql5635@192.168.85.129:3307 --changes-for=server2 --show-reverse --difftype=sql test:test --skip-object-compare --skip-diff # WARNING: Using a password on the command line interface can be insecure. # server1 on 192.168.85.129: ... connected. # server2 on 192.168.85.129: ... connected. # Checking databases test on server1 and test on server2 # # Defn Row Data # Type Object Name Diff Count Check # ------------------------------------------------------------------------- # TABLE test1 SKIP FAIL ERROR: Row counts are not the same among `test`.`test1` and `test`.`test1`.
5、检测表数据的一致性 检查行数同时检查数据是否一致，两表需要有主键或唯一索引。可以使用--skip-checksum-table选项跳过表校验，使用--skip-data-check选项跳过数据检查。
[root@VMUest ~]# mysqldbcompare --server1=mydba:mysql5635@192.168.85.129:3306 --server2=mydba:mysql5635@192.168.85.129:3307 --changes-for=server2 --show-reverse --difftype=sql test:test --skip-object-compare --skip-diff --skip-row-count # WARNING: Using a password on the command line interface can be insecure. # server1 on 192.168.85.129: ... connected. # server2 on 192.168.85.129: ... connected. # Checking databases test on server1 and test on server2 # # Defn Row Data # Type Object Name Diff Count Check # ------------------------------------------------------------------------- # TABLE test1 SKIP SKIP - # - Compare table checksum FAIL # - Find row differences FAIL # # Transformation for --changes-for=server2: # DELETE FROM `test`.`test1` WHERE `id` = '1'; # # Transformation for reverse changes (--changes-for=server1): # # INSERT INTO `test`.`test1` (`id`, `a`, `b`, `c`, `d`) VALUES('1', 'a', 'b', 'c', '1'); # # Database consistency check failed. # # ...done #使用--skip-checksum-table选项跳过表校验 [root@VMUest ~]# mysqldbcompare --server1=mydba:mysql5635@192.168.85.129:3306 --server2=mydba:mysql5635@192.168.85.129:3307 --changes-for=server2 --show-reverse --difftype=sql test:test --skip-object-compare --skip-diff --skip-row-count --skip-checksum-table # WARNING: Using a password on the command line interface can be insecure. # server1 on 192.168.85.129: ... connected. # server2 on 192.168.85.129: ... connected. # Checking databases test on server1 and test on server2 # # Defn Row Data # Type Object Name Diff Count Check # ------------------------------------------------------------------------- # TABLE test1 SKIP SKIP - # - Compare table checksum SKIP # - Find row differences FAIL # # Transformation for --changes-for=server2: # DELETE FROM `test`.`test1` WHERE `id` = '1'; # # Transformation for reverse changes (--changes-for=server1): # # INSERT INTO `test`.`test1` (`id`, `a`, `b`, `c`, `d`) VALUES('1', 'a', 'b', 'c', '1'); # # Database consistency check failed. # # ...done #使用--skip-data-check选项跳过数据检查 [root@VMUest ~]# mysqldbcompare --server1=mydba:mysql5635@192.168.85.129:3306 --server2=mydba:mysql5635@192.168.85.129:3307 --changes-for=server2 --show-reverse --difftype=sql test:test --skip-object-compare --skip-diff --skip-row-count --skip-checksum-table --skip-data-check # WARNING: Using a password on the command line interface can be insecure. # server1 on 192.168.85.129: ... connected. # server2 on 192.168.85.129: ... connected. # Checking databases test on server1 and test on server2 # # Defn Row Data # Type Object Name Diff Count Check # ------------------------------------------------------------------------- # TABLE test1 SKIP SKIP SKIP # Databases are consistent given skip options specified. # # ...done
指定--run-all-tests选项来进行所有的检测
[root@VMUest ~]# mysqldbcompare --server1=mydba:mysql5635@192.168.85.129:3306 --server2=mydba:mysql5635@192.168.85.129:3307 --changes-for=server2 --show-reverse --difftype=sql test:test --run-all-tests # WARNING: Using a password on the command line interface can be insecure. # server1 on 192.168.85.129: ... connected. # server2 on 192.168.85.129: ... connected. # Checking databases test on server1 and test on server2 # # WARNING: Objects in server1.test but not in server2.test: # TABLE: test2 # # Defn Row Data # Type Object Name Diff Count Check # ------------------------------------------------------------------------- # TABLE test1 FAIL FAIL - # - Compare table checksum FAIL # - Find row differences FAIL # # Transformation for --changes-for=server2: # ALTER TABLE `test`.`test1` CHANGE COLUMN c c varchar(10) NULL COMMENT 'c'; # # Transformation for reverse changes (--changes-for=server1): # # ALTER TABLE `test`.`test1` # CHANGE COLUMN c c varchar(10) NULL COMMENT 'cc'; # # Row counts are not the same among `test`.`test1` and `test`.`test1`. # # Transformation for --changes-for=server2: # DELETE FROM `test`.`test1` WHERE `id` = '1'; # # Transformation for reverse changes (--changes-for=server1): # # INSERT INTO `test`.`test1` (`id`, `a`, `b`, `c`, `d`) VALUES('1', 'a', 'b', 'c', '1'); # # Database consistency check failed. # # ...done
检测做复制的sakila库
[root@VMUest ~]# mysqldbcompare --server1=mydba:mysql5635@192.168.85.129:3306 --server2=mydba:mysql5635@192.168.85.129:3307 --changes-for=server2 --show-reverse --difftype=sql sakila:sakila # WARNING: Using a password on the command line interface can be insecure. # server1 on 192.168.85.129: ... connected. # server2 on 192.168.85.129: ... connected. # Checking databases sakila on server1 and sakila on server2 # # Defn Row Data # Type Object Name Diff Count Check # ------------------------------------------------------------------------- # FUNCTION get_customer_balance pass - - # FUNCTION inventory_held_by_customer pass - - # FUNCTION inventory_in_stock pass - - # PROCEDURE film_in_stock pass - - # PROCEDURE film_not_in_stock pass - - # PROCEDURE rewards_report pass - - # TABLE actor pass pass - # - Compare table checksum pass # TABLE address pass pass - # - Compare table checksum pass # TABLE category pass pass - # - Compare table checksum pass # TABLE city pass pass - # - Compare table checksum pass # TABLE country pass pass - # - Compare table checksum pass # TABLE customer pass pass - # - Compare table checksum pass # TABLE film pass pass - # - Compare table checksum pass # TABLE film_actor pass pass - # - Compare table checksum pass # TABLE film_category pass pass - # - Compare table checksum pass # TABLE film_text pass pass - # - Compare table checksum pass # TABLE inventory pass pass - # - Compare table checksum pass # TABLE language pass pass - # - Compare table checksum pass # TABLE payment pass pass - # - Compare table checksum pass # TABLE rental pass pass - # - Compare table checksum pass # TABLE staff pass pass - # - Compare table checksum pass # TABLE store pass pass - # - Compare table checksum pass # TRIGGER customer_create_date pass - - # TRIGGER del_film pass - - # TRIGGER ins_film pass - - # TRIGGER payment_date pass - - # TRIGGER rental_date pass - - # TRIGGER upd_film pass - - # VIEW actor_info pass - - # VIEW customer_list pass - - # VIEW film_list pass - - # VIEW nicer_but_slower_film_list pass - - # VIEW sales_by_film_category pass - - # VIEW sales_by_store pass - - # VIEW staff_list pass - - # Databases are consistent. # # ...done
感觉mysqldbcompare的--run-all-tests选项包括了mysqldiff。mysqldiff如果指定数据库对(db1:db2)，将对比数据库下的对象(不会检查对象的定义)；如果指定具体对象(db1.obj1:db2.obj2)，将对比其定义。
跳过复制错误
在前面对比数据的第5步做Find row differences操作时，会将下面语句写到二进制日志(实际是对比的双方都会有这样的操作，可开启log_bin查看)
现在已经知道主从的test库不一致，下面测试如何跳过复制错误。在主库删除表test2
mysql> drop table test2; Query OK, 0 rows affected mysql> SHOW BINLOG EVENTS in 'mysql-bin.000002' from 16061; +------------------+-------+------------+-----------+-------------+----------------------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-------+------------+-----------+-------------+----------------------------------------------------------+ | mysql-bin.000002 | 16061 | Query | 6 | 16179 | use `test`; DROP TABLE `test2` /* generated by server */ | +------------------+-------+------------+-----------+-------------+----------------------------------------------------------+ 1 row in set
在从库查看复制状态
mysql> show slave statusG *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 127.0.0.1 Master_User: repl Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000002 Read_Master_Log_Pos: 16179 Relay_Log_File: mysql-relay-bin.000005 Relay_Log_Pos: 16224 Relay_Master_Log_File: mysql-bin.000002 Slave_IO_Running: Yes Slave_SQL_Running: No Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 1051 Last_Error: Error 'Unknown table 'test.test2'' on query. Default database: 'test'. Query: 'DROP TABLE `test2` /* generated by server */' Skip_Counter: 0 Exec_Master_Log_Pos: 16061 Relay_Log_Space: 16678 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: NULL Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 1051 Last_SQL_Error: Error 'Unknown table 'test.test2'' on query. Default database: 'test'. Query: 'DROP TABLE `test2` /* generated by server */' Replicate_Ignore_Server_Ids: Master_Server_Id: 6 Master_UUID: 02a05b2c-0557-11e7-bb02-000c29493a20 Master_Info_File: /usr/local/mysql3307/log/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Master_Retry_Count: 86400 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: 170315 14:21:55 Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: Auto_Position: 0 1 row in set (0.00 sec)
报错Unknown table，使用下面语句跳过一个事务
mysql> stop slave; mysql> SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 1; mysql> start slave;
重新查看复制状态
mysql> show slave statusG *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 127.0.0.1 Master_User: repl Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000002 Read_Master_Log_Pos: 16179 Relay_Log_File: mysql-relay-bin.000006 Relay_Log_Pos: 283 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: 16179 Relay_Log_Space: 16678 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: 6 Master_UUID: 02a05b2c-0557-11e7-bb02-000c29493a20 Master_Info_File: /usr/local/mysql3307/log/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it 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 1 row in set (0.00 sec)
对于这种需求明确的通过跳过出错事务就能将主从保持一致。