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。

本文主要描写叙述myloader的用法并给出演示样例。

有关mydumper的相关參考
        mydumper备份mysql数据库演示样例  
        mydumper安装及安装故障汇总  
 
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;             ###创建測试表
>      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 restoredb
restoredb

###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

---添加-o參数进行覆盖恢复
[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以及数据文件运行就可以
[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"

###基于所有备份文件进行恢复
[root@app ~]# myloader  -u leshami -p xxx   -o -d /tmp/bak

4、获取帮助
[root@app ~]# myloader --help
Usage:
  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
                   还原期间每一个事务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