InnoDB storage engine for MySQL has some benefits regarding different database workloads but also has some negative impact which should be taken care of with other services and/or tools. Presentation will also compare significant differences between the two major engines for MySQL - InnoDB and MyISAM and best-practice scenarios for both. ZgPHP Meetup #39 http://www.meetup.com/ZgPHP-meetup/events/205928622/ Video: http://zgphp.org/videos/tomislav-raseta-mysql-engines/ (http://vimeo.com/117263231)

1. MySQL InnoDB
engine vs others
(MyISAM)
Tomislav Rašeta
@traseta

2. me
 scribbling and doodling on *IX operating systems for 10+ years
 working as sysadmin/DevOps with a hint of networking
 tools of the trade
 nginx httpd tomcat (ugh!)
 python php java (ugh!)
 postgresql mysql
 memcached redis mongo

3. PHP & MySQL
 part of the original LAMP
 Linux
 Apache
 MySQL
 PHP
 default database for most PHP developers
 MySQL - used by many, understood by few

4. MySQL storage engine
 stores, handles and retrieves information from a table
 most developers just go with the default in phpMyAdmin (ugh!)
 default engine is set in MySQL configuration file
[mysqld]
default-storage-engine=InnoDB
 Up to MySQL 5.1 default engine was MyISAM, 5.5+ is InnoDB
mysql -uroot -p
Password:
mysql> show engines;

5. concurrency
 MyISAM does table-level locking
 each query waits for its turn to run (ugh!)
 (SELECT * from table anyone?)
 very fast but very dangerous due to the nature of Web transactions
(query pile-up)
 InnoDB does row-level locking
 parallel SELECT/INSERT/UPDATE/DELETE
 does caching for data in indexes in memory
 COUNT(*) is slow (uses full table scan or full index scan if you use WHERE)

6. reliability
 InnoDB is fully ACID compliant
 COMMIT
 ROLLBACK
 referential integrity
 transactions
 crash-recovery capabilities
 MyISAM
 these aren’t the droids you’re looking for, move along now

7. full text search
 MyISAM supports it
 InnoDB supports it from MySQL 5.6
 Don’t use it.
 Using database as a search engine is a BAD IDEA
 Elasticsearch
 Sphinx
 Lucene
 Solr

8. real life examples
 server crash
 InnoDB – data is safe, automatic recovery
 MyISAM – foobar
 high volume* traffic
 InnoDB – row data stored in Primary Key order, data and indexes in
memory, maximum performance, row-level locking
 MyISAM – three separate files, table locking – foobar
 *not your homepage, but something more than 5req/sec

9. tips n tricks
 MOAR Memory
 Databases love it
 Memory is cheap
 innodb_buffer_pool set to 80% of total memory works wonders for InnoDB
 key_buffer set to high amount in MyISAM just means you’re going to lose a
lot more data if server crashes – but blazing fast!
 MOAR Cores
 new generation processors use less energy, less clock speed but more cores
 Getting cheaper every day
 Aim for the ones with big L2/L3 cache and high clock / more cores
 ultimate decision depends on your database workload

10. tips n tricks
 MOAR IOPS
 SSDs (be careful!)
 A bunch of rotational disks (Storage array)
 Ideally
 Dual/Quad Multi-core high-clock CPU’s (Intel Xeon E3/E5/E7 v3)
 A bunch of memory
 Enterprise-level SSDs (no Desktop SSDs!)

11. performance

12. performance

13. performance

14. MySQL forks
 don’t use the original
 Percona (nice tools and XtraDB)
 MariaDB
 Drizzle
 MySQL Enterprise
 $$$$$$$

15. DO NOT
 combine MyISAM and InnoDB on same database server
 too much hassle to find the optimum ratio of buffers
 JOIN’s between tables with different storage engines fallbacks to the
less featured (MyISAM)
 there be dragons
 use full text search
 just don’t do it, please
 rely on database only
 memcached

16. migrating to InnoDB
 ALTER TABLE table1 ENGINE=InnoDB;
 locks table
 Dump SQL, search/replace MyISAM -> InnoDB, Restore SQL
 timely process
 if using Percona MySQL fork
 pt-online-schema-change --alter "ENGINE=InnoDB" D=database,t=table
 doesn’t work if you use triggers on tables
 try to adapt to your requirements (downtime, server speed etc.)

17. monitor all the things!
 slow query logs
 http://mysqltuner.pl
 cacti graphs
 newrelic
 MONyog
 don’t blame database if your queries are stupid
 don’t blame database if your application stupid

18. conclusion
 InnoDB FTW!

19. thanks
 questions?