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
在原版的基础上做了一下修正：增加1st在线支付功能与论坛用户数据结合，vip也可与论坛相关，增加互动性vip会员的全面修正评论没有提交正文的问题特价商品的调用连接问题删掉了2个木马文件去掉了一个后门补了SQL注入补了一个过滤漏洞浮动价不能删除的问题不能够搜索问题收藏时放入购物车时出错点放入购物车弹出2个窗口修正定单不能删除问题VIP出错问题主题添加问题商家注册页导航连接问题添加了导航FLASH源文
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。
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