mydumper是针对mysql数据库备份的一个轻量级第三方的开源工具，备份方式为逻辑备份。它支持多线程，备份速度远高于原生态的mysqldump以及众多优异特性。与其相配套的恢复工具则是myloader，主要用于将dump出来的sql以并行的方式进行恢复。本文主要描述myloader的使用方法并给出示例。

    有关mydumper的相关参考

                       1、单库的备份与恢复[root@app ~]# mydumper -u leshami -p xxx -B sakila -o /tmp/bak[root@app ~]# mysql -urobin -pxxx   -e "show databases"|grep restoredb[root@app ~]# mysql -urobin -pxxx   \>  -e "create table sakila.tb like sakila.actor;             ###创建测试表>      insert into sakila.tb select * from sakila.actor"

###将备份库恢复到一个新数据库，如restoredb

[root@app ~]# myloader  -u leshami -p xxx  -B restoredb -d /tmp/bak[root@app ~]# mysql -urobin -pxxx   -e "show databases"|grep restoredbrestoredb

###恢复到原库

[root@app ~]# myloader  -u leshami -p xxx   -B sakila -d /tmp/bak** (myloader:3642): CRITICAL **: Error restoring sakila.category from file sakila.category-schema.sql: Table 'category' already exists

---增加-o参数进行覆盖恢复

[root@app ~]# myloader  -u leshami -p xxx   -o -B sakila -d /tmp/bak

2、单表恢复

[root@app ~]# mysql -urobin -pxxx   -e "drop table sakila.tb"[root@app ~]# mysql -urobin -pxxx   -e "select count(*) from sakila.tb"Warning: Using a password on the command line interface can be insecure.ERROR 1146 (42S02) at line 1: Table 'sakila.tb' doesn't exist

###直接调用备份的schema以及数据文件执行即可

[root@app ~]# mysql -urobin -pxxx   \>  -e "use sakila;>      source /tmp/bak/sakila.tb-schema.sql>      source /tmp/bak/sakila.tb.sql"

###验证结果

[root@app ~]# mysql -urobin -pxxx   -e "select count(*) from sakila.tb"Warning: Using a password on the command line interface can be insecure.+----------+| count(*) |+----------+|      200 |+----------+

3、实例级别的备份与恢复

[root@app ~]# rm -rf /tmp/bak/*[root@app ~]# mydumper -u leshami -p xxx   --regex '^(?!(mysql|test))' -o /tmp/bak

###尝试删除部分数据库

[root@app ~]# mysql -urobin -pxxx   \>  -e "drop database tempdb;drop database sakila"

###基于全部备份文件进行恢复

[root@app ~]# myloader  -u leshami -p xxx   -o -d /tmp/bak

4、获取帮助

[root@app ~]# myloader --helpUsage:  myloader [OPTION...] multi-threaded MySQL loader

Help Options:

  -?, --help                        Show help options

Application Options:

  -d, --directory                   Directory of the dump to import  -q, --queries-per-transaction     Number of queries per transaction, default 1000                   还原期间每个事务insert的数目，缺省是1k  -o, --overwrite-tables            Drop tables if they already exist(表存在即覆盖)  -B, --database                    An alternative database to restore into  -e, --enable-binlog               Enable binary logging of the restore data  -h, --host                        The host to connect to  -u, --user                        Username with privileges to run the dump  -p, --password                    User password  -P, --port                        TCP/IP port to connect to  -S, --socket                      UNIX domain socket file to use for connection  -t, --threads                     Number of threads to use, default 4  -C, --compress-protocol           Use compression on the MySQL connection  -V, --version                     Show the program version and exit  -v, --verbose                     Verbosity of output, 0 = silent, 1 = errors, 2 = warnings, 3 = info, default 2