MySQL any way to import a huge (32 GB) sql dump faster?

Question

I have this huge 32 GB SQL dump that I need to import into MySQL. I haven't had to import such a huge SQL dump before. I did the usual:

mysql -uroot dbname < dbname.sql

It is taking too long. There is a table with around 300 million rows, it's gotten to 1.5 million in around 3 hours. So, it seems that the whole thing would take 600 hours (that's 24 days) and is impractical. So my question is, is there a faster way to do this?

Further Info/Findings

1. The tables are all InnoDB and there are no foreign keys defined. There are, however, many indexes.
2. I do not have access to the original server and DB so I cannot make a new back up or do a "hot" copy etc.
3. Setting innodb_flush_log_at_trx_commit = 2 as suggested here seems to make no (clearly visible/exponential) improvement.
4. Server stats during the import (from MySQL Workbench): https://imgflip.com/gif/ed0c8.
5. MySQL version is 5.6.20 community.
6. innodb_buffer_pool_size = 16M and innodb_log_buffer_size = 8M. Do I need to increase these?

Answer 1

Percona's Vadim Tkachenko made this fine Pictorial Representation of InnoDB

You definitely need to change the following

innodb_buffer_pool_size = 4G
innodb_log_buffer_size = 256M
innodb_log_file_size = 1G
innodb_write_io_threads = 16
innodb_flush_log_at_trx_commit = 0

Why these settings ?

• innodb_buffer_pool_size will cache frequently read data
• innodb_log_buffer_size : Larger buffer reduces write I/O to Transaction Logs
• innodb_log_file_size : Larger log file reduces checkpointing and write I/O
• innodb_write_io_threads : Service Write Operations to .ibd files. According to MySQL Documentation on Configuring the Number of Background InnoDB I/O Threads, each thread can handle up to 256 pending I/O requests. Default for MySQL is 4, 8 for Percona Server. Max is 64.
• innodb_flush_log_at_trx_commit
  • In the event of a crash, both 0 and 2 can lose once second of data.
  • The tradeoff is that both 0 and 2 increase write performance.
  • I choose 0 over 2 because 0 flushes the InnoDB Log Buffer to the Transaction Logs (ib_logfile0, ib_logfile1) once per second, with or without a commit. Setting 2 flushes the InnoDB Log Buffer only on commit. There are other advantages to setting 0 mentioned by @jynus, a former Percona instructor.

Restart mysql like this

service mysql restart --innodb-doublewrite=0

This disables the InnoDB Double Write Buffer

Import your data. When done, restart mysql normally

service mysql restart

This reenables the InnoDB Double Write Buffer

Give it a Try !!!

SIDE NOTE : You should upgrade to 5.6.21 for latest security patches.

Answer 2

Do you really need the entire database to be restored? If you don't, my 2c:

You can extract specific tables to do your restore on "chunks". Something like this:

zcat your-dump.gz.sql | sed -n -e '/DROP TABLE.*`TABLE_NAME`/,/UNLOCK TABLES/p' > table_name-dump.sql

I did it once and it took like 10 minutes to extract the table I needed - my full restore took 13~14 hours, with a 35GB (gziped) dump.

The /pattern/,/pattern/p with the -n parameter makes a slice "between the patterns" - including them.

Anyways, to restore the 35GB I used an AWS EC2 machine (c3.8xlarge), installed Percona via yum (Centos) and just added/changed the following lines on my.cnf:

max_allowed_packet=256M
wait_timeout=30000

I think the numbers are way too high, but worked for my setup.

Answer 3

One way to help speed up the import is to lock the table while importing. Use the --add-locks option to mysqldump.

mysqldump --add-drop-table --add-locks --database db > db.sql

or you could turn on some useful parameters with --opt this turns on a bunch of useful things for the dump.

mysqldump --opt --database db > db.sql

If you have another storage device on the server, then use that - copying from one device to another is a way to speed up transfers.

You can also filter out tables that are not required with --ignore-table

Answer 4

The fastest way to import your database is to copy the ( .frm, .MYD, .MYI ) files if MyISAM, directly to the /var/lib/mysql/"database name".

Otherwise you can try : mysql > use database_name; \. /path/to/file.sql

Thats another way to import your data.

Answer 5

This is how to set RolandoMySQLDBA configuration in linux:

1. Open mysql conf file in your favourite text editor:

   sudo vi /etc/mysql/my.conf

2. Type the following configuration at the end of the file:

    [mysqld]
    innodb_buffer_pool_size = 4G
    innodb_log_buffer_size = 256M
    innodb_log_file_size = 1G
    innodb_write_io_threads = 16
    innodb_flush_log_at_trx_commit = 0
    innodb_doublewrite = 0

3. Save the file and run this command in mysql:

   set global innodb_fast_shutdown = 0

   you can see the new configuration with @@ followed by command in mysql:

   select @@innodb_buffer_pool_size;

   similarly with other commands

4. Restart mysql:

   service mysql restart

5. Restore your database state:

   mysql -u username -p database_name < /path/to/file.sql

I had to import 5.8GB of data which took me 40min with the pc configuration of inter corei5 2.5GHZ and 16gb ram