Anthropomorphic DesignMaking a Better WordPress with Jazz Hands
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But seriously….
HyperDB, MySQL
Performance, & Flavors of
MySQLEvan Volgas
About me
• 10 years working with data — as an analyst, a
DBA, etc
• Currently a data engineer for WhatRunsWhere
• Data Engineer = DBA + Map Reduce + PTSD
from Apache Zookeeper
• Worked with WordPress off/on for about ~5 years
Disclaimers
I believe
• Google exists
• You can use it
• You don’t enjoy reading a bunch of code and
config files in a presentation any more than I do
• WordCamp needs more cowbell
What is
HyberDB?
• “Very advanced database class”
• Powers WordPress.com
• Supports replication, partitioning, load balancing,
etc
“Very advanced database class”
find 'hyperdb/' -name '*.php' | xargs wc -l
• HyperDB: 1,401 lines of PHP
• WordPress: 255,961 lines of PHP
• Hello Dolly: 81 lines of PHP
• Yoast’s Google Analytics 16,174 lines of PHP
Why’d you have to go and make
things so complicated
• The complexity of HyperDB has nothing to do with
the PHP code itself
• Implementing HyperDB itself is mostly
configuration
• To the extent that HyperDB is advanced, it’s
because MySQL has a lot of advanced stuff going
on underneath the hood
Who cares about MySQL?
An argument from fellow WordCamp ATL
presenter Tom McFarlin*
• Employers haven’t fully figured out what
WordPress *can* do
• WordPress makes it easy to be a software
implementer as opposed to a software
developer so in a lot of cases salaries probably
should be lower
• The WordPress community itself hasn’t
educated employers, customers, or software
implementors how classical software
development / engineering can fit into the
WordPress ecosystem
*https://tommcfarlin.com/wordpress-developer-
salary/
Tell me again why this matters
• We don’t need any more social media icons plugin
• Many of the things that are really pushing the
WordPress envelope are VERY database
intensive and their performance needs are poorly
understood
• There are a million things you can (and should) do
to optimize your WordPress website. When those
stop being enough, it’d be a good idea to know
some DB basics
HyperDB
• For practical extents and purposes, it’s kind of like a
giant wp-config.php that pertains to your database
• A lot of great resources for setting it up. If you
decide you want to try it, make sure you check out
https://www.digitalocean.com/community/tutorials/how-to-optimize-wordpress-
performance-with-mysql-replication-on-ubuntu-14-04
http://wpguru.co.uk/2010/07/testing-hyperdb/
http://codertalks.com/configuring-hyperdb-to-use-multiple-databases-for-buddypress-
multisite/
MySQL Lingo + Discussion
• Replication
• Statement vs Row-based
• Master vs Slave
• Partitioning
• Tends to either really help or really hurt you — very little in between
• NB: One of the reasons NoSQL has market adoption is because this is very painful
• Latency matters: https://gist.github.com/jboner/2841832
• Failover
• Load Balancing
• DB: HyperDB
• Web app: HA Proxy, Nginx, etc
MySQL Performance Basics
• innodb_buffer_pool_size: 70-80% of memory is common
• innodb_buffer_pool_instances: if you have a lot of memory, you might
run into bottlenecks where multiple threads are trying to access the buffer
pool. Splitting it up into multiple buffer pools can help
• innodb_file_per_table: if you are using < MySQL 5.6, turn this on. Trust
me.
• max_connections: if you ever think you need to tweak this, double check
that your connections are terminating properly
• log_bin: your master nodes needs this
• slow-query-log, slow-query-log-file, long_query_time: log your slow
queries. Don’t go crazy, but periodically log everything and analyze it
MySQL Best PracticesMonitor everything
• New Relic, Datadog, Zabbix, graphite/statsd/collectd
• http://www.percona.com/live/mysql-conference-
2013/sites/default/files/slides/percona-live-santa-clara-2013-presentation-
spilgames-mysql-statsd.pdf <— Interesting idea
Analyze your queries
• pt-query-digest, mysqldumpslow, plugins for third party monitoring
Learn how to reason about the Query Execution Plan
• http://www.sitepoint.com/using-explain-to-write-better-mysql-queries/
Schedule DB maintenance
Flavors of MySQL
• MySQL
• MariaDB
• https://mariadb.com/blog/how-install-and-run-
wordpress-mariadb
• Percona:
• https://www.digitalocean.com/community/tutorials/ho
w-to-install-a-fresh-percona-server-or-replace-mysql
Special Mention
Percona Toolkit
• http://www.percona.com/doc/percona-toolkit/2.2/
pt-query-digest --since '2014-11-01' --filter '$event->{arg} =~ m/^select/i' /var/log/mysql/slow-query.log >
/tmp/pt_slow_since_nov2014
Nginx + PHP-FPM
• http://www.raspipress.com/2014/06/tutorial-install-wordpress-on-a-
raspberry-pi-using-nginx/
Learn from people within WordPress and from outside of it
• good example: https://roots.io/twelve-factor-wordpress/