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| 导读 | 通过上述方法可以快速备份恢复大数据量的库，也可以同时指定多个库，单张表或多张表进行恢复。可参考官方文档 Partial Backups – Percona XtraBackup。 |
1. 概述
本文通过 XtraBackup 备份单个数据库，然后恢复到另一个实例，用于快速迁移大数据量，使用的软件版本为：
|
软件名 |
版本 |
|
MySQL |
mysql-5.7.39-linux-glibc2.12-x86_64.tar.gz |
|
XtraBackup |
percona-xtrabackup-24-2.4.26-1.el7.x86_64.rpm |
在 2 台主机分别安装一个 MySQL 实例：
|
主机 |
IP 地址 |
端口号 |
|
MySQL-A |
192.168.100.10 |
5508 |
|
MySQL-B |
192.168.100.11 |
5508 |
2. 在 MySQL- A 初始化数据
通过 sysbench 初始化数据，10 张表，每张表 10000 条记录
shell> sysbench src/lua/oltp_read_write.lua --mysql-db=sysbench --mysql-host=192.168.100.10 --mysql-port=5508 --mysql-user=greatsql --mysql-password='greatsql' --tables=10 --table_size=10000 --report-interval=2 --threads=50 --time=1000 --mysql_storage_engine=innodb --partitions=3 --skip_trx=0 --mysql-ignore-errors=all prepare3. 通过 xtrabackup 备份 MySQL-A 的 sysbench 库
shell> innobackupex --defaults-file=/mysql/conf/my5508.cnf --user greatsql --password greatsql -H127.0.0.1 -P5508 --databases sysbench /mysql/dbbackup
...
...
221229 10:11:17 Executing UNLOCK TABLES
221229 10:11:17 All tables unlocked
221229 10:11:17 [00] Copying ib_buffer_pool to /mysql/dbbackup/2022-12-29_10-11-07/ib_buffer_pool
221229 10:11:17 [00] ...done
221229 10:11:17 Backup created in directory '/mysql/dbbackup/2022-12-29_10-11-07/'
MySQL binlog position: filename 'binlog.000005', position '190', GTID of the last change '3e362a47-8683-11ed-92e1-00163ed294ac:1-87'
221229 10:11:17 [00] Writing /mysql/dbbackup/2022-12-29_10-11-07/backup-my.cnf
221229 10:11:17 [00] ...done
221229 10:11:17 [00] Writing /mysql/dbbackup/2022-12-29_10-11-07/xtrabackup_info
221229 10:11:17 [00] ...done
xtrabackup: Transaction log of lsn (1123405728) to (1123405737) was copied.
221229 10:11:17 completed OK!4. 备份 MySQL-A sysbench 库的表结构
shell> /mysql/svr/mysql/bin/mysqldump -ugreatsql -pgreatsql -h127.0.0.1 -P5508 --single-transaction --set-gtid-purged=OFF --master-data=2 -d -B sysbench > sysbench.sql
mysqldump: [Warning] Using a password on the command line interface can be insecure.5. 将备份的 sysbench 库的表结构导入 MySQL-B
shell> /mysql/svr/mysql/bin/mysql -ugreatsql -pgreatsql -h192.168.100.11 -P5508
6. 登录 MySQL-B 生成丢弃 / 导入表空间的 SQL 语句
# 生成丢弃表空间的 SQL
mysql> select concat('alter table',table_schema,'.',TABLE_NAME , 'discard tablespace', ';') from information_schema.tables where TABLE_SCHEMA = 'sysbench' into outfile '/tmp/discard.sql';
Query OK, 10 rows affected (0.00 sec)
# 生成导入表空间的 SQL
mysql> select concat('alter table',table_schema,'.',TABLE_NAME , 'import tablespace', ';') from information_schema.tables where TABLE_SCHEMA = 'sysbench' into outfile '/tmp/import.sql';
Query OK, 10 rows affected (0.01 sec)7. 登录 MySQL-B 执行丢弃表空间的 SQL 语句
mysql> source /tmp/discard.sql;8. 查看 MySQL-B 底层数据文件
shell> ll -h /mysql/dbdata/data5508/data/sysbench/
total 124K
-rw-r----- 1 mysql mysql 67 Dec 29 10:25 db.opt
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:25 sbtest10.frm
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:25 sbtest1.frm
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:25 sbtest2.frm
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:26 sbtest3.frm
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:26 sbtest4.frm
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:26 sbtest5.frm
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:26 sbtest6.frm
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:26 sbtest7.frm
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:26 sbtest8.frm
-rw-r----- 1 mysql mysql 8.5K Dec 29 10:26 sbtest9.frm可以看到 ibd 文件已被丢弃
9.prepare 备份文件
注意这里需要加 --export 选项，它允许导出单个表以进行导入到另一个服务器
shell> innobackupex --apply-log --export /mysql/dbbackup/2022-12-29_10-11-07
xtrabackup: recognized server arguments: --innodb_checksum_algorithm=crc32 --innodb_log_checksum_algorithm=strict_crc32 --innodb_data_file_path=ibdata1:12M:autoextend --innodb_log_files_in_group=4 --innodb_log_file_size=33554432 --innodb_fast_checksum=0 --innodb_page_size=16384 --innodb_log_block_size=512 --innodb_undo_directory=/mysql/dbdata/data5508/log --innodb_undo_tablespaces=0 --server-id=2 --redo-log-version=1
xtrabackup: recognized client arguments:
221229 10:56:58 innobackupex: Starting the apply-log operation
IMPORTANT: Please check that the apply-log run completes successfully.
At the end of a successful apply-log run innobackupex
prints "completed OK!".
...
...
xtrabackup: starting shutdown with innodb_fast_shutdown = 0
InnoDB: FTS optimize thread exiting.
InnoDB: Starting shutdown...
InnoDB: Shutdown completed; log sequence number 1123519528
221229 10:57:13 completed OK!10. 查看备份文件目录
shell> ll -h /mysql/dbbackup/2022-12-29_10-11-07/sysbench/
total 271M
-rw-r----- 1 root root 67 Dec 29 10:11 db.opt
-rw-r----- 1 root root 8.5K Dec 29 10:11 sbtest10.frm
-rw-r--r-- 1 root root 578 Dec 29 10:57 sbtest10#P#p0.cfg
-rw-r----- 1 root root 16K Dec 29 10:57 sbtest10#P#p0.exp
-rw-r----- 1 root root 9.0M Dec 29 10:11 sbtest10#P#p0.ibd
-rw-r--r-- 1 root root 578 Dec 29 10:57 sbtest10#P#p1.cfg
-rw-r----- 1 root root 16K Dec 29 10:57 sbtest10#P#p1.exp
-rw-r----- 1 root root 9.0M Dec 29 10:11 sbtest10#P#p1.ibd
-rw-r--r-- 1 root root 578 Dec 29 10:57 sbtest10#P#p2.cfg
...可以看到 prepare 备份文件后，多了 cfg,exp 结尾的文件
11. 传输备份文件
将准备好的备份文件中后缀名为 cfg，ibd，exp 的文件传输到 MySQL- B 实例的 sysbench 库下
shell> scp -r /mysql/dbbackup/2022-12-29_10-11-07/sysbench/*.ibd /mysql/dbbackup/2022-12-29_10-11-07/sysbench/*.cfg /mysql/dbbackup/2022-12-29_10-11-07/sysbench/*.exp root@192.168.100.11:/mysql/dbdata/data5508/data/sysbench/12. 修改传输过来的文件的属主属组
shell> chown -R mysql.mysql /mysql13. 登录 MySQL-B 执行导入表空间的 SQL 语句
mysql> source /tmp/import.sql;14. 登录 MySQL-B 检查一张表是否正常
mysql> select count(*) from sysbench.sbtest1;
+----------+
| count(*) |
+----------+
| 10000 |
+----------+
1 row in set (0.01 sec)15. 使用 sysbench 进行压测 MySQL-B
shell> sysbench src/lua/oltp_read_write.lua --mysql-db=sysbench --mysql-host=192.168.100.11 --mysql-port=5508 --mysql-user=greatsql --mysql-password='greatsql' --tables=10 --table_size=10000 --report-interval=2 --threads=50 --time=300 --mysql_storage_engine=innodb --partitions=3 --skip_trx=0 --mysql-ignore-errors=all run
sysbench 1.1.0-df89d34 (using bundled LuaJIT 2.1.0-beta3)
...
...
SQL statistics:
queries performed:
read: 1702400
write: 486400
other: 243200
total: 2432000
transactions: 121600 (405.25 per sec.)
queries: 2432000 (8105.04 per sec.)
ignored errors: 0 (0.00 per sec.)
reconnects: 0 (0.00 per sec.)
Throughput:
events/s (eps): 405.2522
time elapsed: 300.0601s
total number of events: 121600
Latency (ms):
min: 9.04
avg: 123.36
max: 1512.19
95th percentile: 590.56
sum: 15000942.35
Threads fairness:
events (avg/stddev): 2432.0000/58.48
execution time (avg/stddev): 300.0188/0.01压测正常
16. 重启 MySQL- B 并查询一张表
mysql> shutdown;
shell> /mysql/svr/mysql/bin/mysqld_safe --defaults-file=/mysql/conf/my5508.cnf --user=mysql &
mysql> select count(*) from sysbench.sbtest2;
+----------+
| count(*) |
+----------+
| 10000 |
+----------+
1 row in set (0.04 sec) 总结
通过上述方法可以快速备份恢复大数据量的库，也可以同时指定多个库，单张表或多张表进行恢复。可参考官方文档 Partial Backups - Percona XtraBackup。
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