mydumper myloader表分块导入导出

mydumper与myloader是一个优秀的第三方mysql数据库逻辑备份恢复工具，使用多线程的导出与导入。弥补了mysqldump单线程的不足。本文描述的是如何加快mydumper与myloader的导出与导入供大家参考。

有关mydumper与myloader其他事项可以参考：

mydumper安装及安装故障汇总

mydumper备份mysql数据库示例

myloader恢复mysql数据库示例

1、基于MyIsam引擎导出导入

a、表不分块导出及导入

[root@GZAPP tmp]# mydumper -u inno -p xxx -B bsom -T tb_access_log -o /backup/tmp/

[root@GZAPP tmp]# ls -hltr ###导出的数据文件为单个文件，大小在2.6GB

total 2.6G

-rw-r--r-- 1 root root 1.6K Jul 24 08:51 bsom.tb_access_log-schema.sql

-rw-r--r-- 1 root root 214 Jul 24 08:52 metadata

-rw-r--r-- 1 root root 2.6G Jul 24 08:52 bsom.tb_access_log.sql

###基于缺省线程数导入，且设定每个事务查询数为10000，此参数此时其实作用不大，因为表为myisam引擎

[root@GZAPP tmp]# myloader -u inno -p xxx -B tempdb -d /backup/tmp -v 3 -q 10000

[root@GZAPP tmp]# myloader -u inno -p xxx -B tempdb -d /backup/tmp -v 3 -q 10000

** Message: 4 threads created

** Message: Creating table `tempdb`.`tb_access_log`

** Message: Thread 4 shutting down

** Message: Thread 1 restoring `bsom`.`tb_access_log` part 0

** Message: Thread 3 shutting down

** Message: Thread 2 shutting down

root@localhost[tempdb]> show processlist;

+---------+---------+----------+--------+---------+--------+---------+------------------------------------------------+

| Id | User | Host | db | Command | Time | State | Info |

+---------+---------+----------+--------+---------+--------+---------+------------------------------------------------+

| 4452079 | root | localhost| tempdb | Query | 0 | init | show processlist |

| 4453793 | inno | localhost| tempdb | Sleep | 420 | | NULL |

| 4453794 | inno | localhost| tempdb | Query | 4 | update | INSERT INTO `tb_access_log` VALUES (506873,"325|

+---------+---------+----------+--------+---------+--------+---------+------------------------------------------------+

###从上面的线程数可以看出只有一个单线程在执行insert操作

b、表分块导出及导入

###下面的示例中使用500MB进行分块

[root@GZAPP tmp]# mydumper -u inno -p xxx -B bsom -T tb_access_log -F 500 -o /backup/tmp/

[root@GZAPP tmp]# ls -hltr

total 2.6G

-rw-r--r-- 1 root root 1.6K Jul 24 08:21 bsom.tb_access_log-schema.sql

-rw-r--r-- 1 root root 478M Jul 24 08:21 bsom.tb_access_log.00001.sql

-rw-r--r-- 1 root root 478M Jul 24 08:21 bsom.tb_access_log.00002.sql

-rw-r--r-- 1 root root 478M Jul 24 08:21 bsom.tb_access_log.00003.sql

-rw-r--r-- 1 root root 478M Jul 24 08:21 bsom.tb_access_log.00004.sql

-rw-r--r-- 1 root root 478M Jul 24 08:22 bsom.tb_access_log.00005.sql

-rw-r--r-- 1 root root 214 Jul 24 08:22 metadata

-rw-r--r-- 1 root root 241M Jul 24 08:22 bsom.tb_access_log.00006.sql

###由上可知，大表tb_access_log按接近500M被分割成了多个文件

[root@GZAPP tmp]# myloader -u inno -p xxx -B tempdb -t 6 -d /backup/tmp -v 3

** Message: 6 threads created

** Message: Creating database `tempdb`

** Message: Creating table `tempdb`.`tb_access_log`

** Message: Thread 1 restoring `bsom`.`tb_access_log` part 3

** Message: Thread 2 restoring `bsom`.`tb_access_log` part 5

** Message: Thread 5 restoring `bsom`.`tb_access_log` part 4

** Message: Thread 3 restoring `bsom`.`tb_access_log` part 6

** Message: Thread 4 restoring `bsom`.`tb_access_log` part 1

** Message: Thread 6 restoring `bsom`.`tb_access_log` part 2

#在下面的processlist可以看到，存在表级锁等待

+---------+-------+-----------+---------+---------+--------+-----------------------------+------------------------------------------------+

| Id | User | Host | db | Command | Time | State | Info |

+---------+-------+-----------+---------+---------+--------+-----------------------------+------------------------------------------------+

| 4452079 | root | localhost | bsom | Query | 0 | init | show processlist |

| 4452167 | inno | localhost | tempdb | Sleep | 769 | | NULL |

| 4452168 | inno | localhost | tempdb | Query | 36 | update | INSERT INTO `tb_access_log` VALUES (6367402,"0,|

| 4452169 | inno | localhost | tempdb | Query | 21 | Waiting for table level lock| INSERT INTO `tb_access_log` VALUES (12593865," |

| 4452170 | inno | localhost | tempdb | Query | 26 | Waiting for table level lock| INSERT INTO `tb_access_log` VALUES (15643029,""|

| 4452171 | inno | localhost | tempdb | Query | 6 | Waiting for table level lock| INSERT INTO `tb_access_log` VALUES (173947,"70 |

| 4452172 | inno | localhost | tempdb | Query | 15 | Waiting for table level lock| INSERT INTO `tb_access_log` VALUES (9490507,"7 |

| 4452173 | inno | localhost | tempdb | Query | 30 | Waiting for table level lock| INSERT INTO `tb_access_log` VALUES (3271602,"4 |

+---------+---------+-----------+---------+---------+--------+-----------------------------+----------------------------------------------+

c、调整myisam有关参数后导入

[root@GZ-APP-BAK01 tmp]# time myloader -u innobk -p InnoBK -B tempdb -t 6 -d /backup/tmp -v 3

** Message: 6 threads created

** Message: Creating table `tempdb`.`tb_mobile_access_log`

** Message: Thread 1 restoring `blossom`.`tb_mobile_access_log` part 3

** Message: Thread 6 restoring `blossom`.`tb_mobile_access_log` part 6

** Message: Thread 2 restoring `blossom`.`tb_mobile_access_log` part 5

** Message: Thread 3 restoring `blossom`.`tb_mobile_access_log` part 4

** Message: Thread 4 restoring `blossom`.`tb_mobile_access_log` part 1

** Message: Thread 5 restoring `blossom`.`tb_mobile_access_log` part 2

** Message: Thread 6 shutting down

** Message: Thread 5 shutting down

** Message: Thread 1 shutting down

** Message: Thread 2 shutting down

** Message: Thread 4 shutting down

** Message: Thread 3 shutting down

real 266m28.903s

user 0m6.008s

sys 0m1.681s

###调整以下相关参数，后尝试再次导入，

concurrent_insert AUTO 改成 ALWAYS

bulk_insert_buffer_size 8388608 改成 256M

myisam_sort_buffer_size 67108864 改成 128M

[root@GZ-APP-BAK01 tmp]# time myloader -u innobk -p InnoBK -B tempdb -t 6 -o -d /backup/tmp -v 3

** Message: 6 threads created

** Message: Dropping table (if exists) `tempdb`.`tb_mobile_access_log`

** Message: Creating table `tempdb`.`tb_mobile_access_log`

** Message: Thread 1 restoring `blossom`.`tb_mobile_access_log` part 3

** Message: Thread 2 restoring `blossom`.`tb_mobile_access_log` part 6

** Message: Thread 3 restoring `blossom`.`tb_mobile_access_log` part 5

** Message: Thread 4 restoring `blossom`.`tb_mobile_access_log` part 4

** Message: Thread 6 restoring `blossom`.`tb_mobile_access_log` part 1

** Message: Thread 5 restoring `blossom`.`tb_mobile_access_log` part 2

** Message: Thread 2 shutting down

** Message: Thread 1 shutting down

** Message: Thread 6 shutting down

** Message: Thread 5 shutting down

** Message: Thread 3 shutting down

** Message: Thread 4 shutting down

real 253m42.460s ###此时导入时间并无明显减少

user 0m5.924s

sys 0m1.637s

2、基于innodb引擎的导出导入

a、表未分块导出，数据文件大小为3.9GB

[root@GZAPP tmp]# ls -hltr

total 3.9G

-rw-r--r-- 1 root root 1.8K Jul 24 00:09 bscom.tb_message-schema.sql

-rw-r--r-- 1 root root 3.9G Jul 24 00:25 bscom.tb_message.sql

-rw-r--r-- 1 root root 215 Jul 24 09:14 metadata

###下面使用6个线程导入，实际上可以看到，只有1个线程在工作，因为数据文件只有1个

[root@GZAPP tmp]# myloader -u inno -p xxx -B tempdb -t 6 -d /backup/tmp -v 3

** Message: 6 threads created

** Message: Creating table `tempdb`.`tb_message`

** Message: Thread 1 restoring `bscom`.`tb_message` part 0

** Message: Thread 5 shutting down

** Message: Thread 2 shutting down

** Message: Thread 6 shutting down

** Message: Thread 3 shutting down

** Message: Thread 4 shutting down

b、表分块导出

[root@GZAPP tmp]# mydumper -u inno -p xxx -B bscom -T tb_message -F 500 -o /backup/tmp/

[root@GZAPP tmp]# ls -hltr

total 3.9G

-rw-r--r-- 1 root root 1.8K Jul 24 09:55 bscom.tb_message-schema.sql

-rw-r--r-- 1 root root 478M Jul 24 09:55 bscom.tb_message.00001.sql

-rw-r--r-- 1 root root 478M Jul 24 09:55 bscom.tb_message.00002.sql

-rw-r--r-- 1 root root 478M Jul 24 09:55 bscom.tb_message.00003.sql

-rw-r--r-- 1 root root 478M Jul 24 09:55 bscom.tb_message.00004.sql

-rw-r--r-- 1 root root 478M Jul 24 09:55 bscom.tb_message.00005.sql

-rw-r--r-- 1 root root 478M Jul 24 09:55 bscom.tb_message.00006.sql

-rw-r--r-- 1 root root 478M Jul 24 09:55 bscom.tb_message.00007.sql

-rw-r--r-- 1 root root 481M Jul 24 09:55 bscom.tb_message.00008.sql

-rw-r--r-- 1 root root 135 Jul 24 09:55 metadata

-rw-r--r-- 1 root root 93M Jul 24 09:55 bscom.tb_message.00009.sql

###下面尝试使用6线程导入，可以看到有6个线程在并发导入

[root@GZAPP tmp]# myloader -u inno -p xxx -B tempdb -t 6 -d /backup/tmp/ -v 3

** Message: 6 threads created

** Message: Creating database `tempdb`

** Message: Creating table `tempdb`.`tb_message`

** Message: Thread 2 restoring `bscom`.`tb_message` part 5

** Message: Thread 1 restoring `bscom`.`tb_message` part 9

** Message: Thread 3 restoring `bscom`.`tb_message` part 1

** Message: Thread 4 restoring `bscom`.`tb_message` part 8

** Message: Thread 5 restoring `bscom`.`tb_message` part 4

** Message: Thread 6 restoring `bscom`.`tb_message` part 6

** Message: Thread 1 restoring `bscom`.`tb_message` part 7

** Message: Thread 6 restoring `bscom`.`tb_message` part 3

** Message: Thread 2 restoring `bscom`.`tb_message` part 2

** Message: Thread 3 shutting down

** Message: Thread 5 shutting down

** Message: Thread 4 shutting down

** Message: Thread 1 shutting down

** Message: Thread 2 shutting down

** Message: Thread 6 shutting down

3、小结

a、mydumper在导出的时候可以根据服务器可用资源来合理地设置线程数。

b、mydumper在导出的时候尽可能地指定chunk-filesize或者rows参数以分块导出。

c、myloader在针对myisam引擎时建议调整相关参数至合理值以提高无法提高性能，主要是表级锁的问题。

d、myloader在针对innodb引擎时建议调整参数至合理值以提高性能，如以下参数等：

innodb_buffer_pool_size

innodb_flush_log_at_trx_commit

innodb_log_buffer_size

e、通过使用分块导出与导入可以显著利用并发来加快inndbo表导入。

f、注意mydumper导出时不会导出存储过程，函数，触发器等。