⚓ T96249 MySQL tuning on CI slaves (tracking)

Status	Assigned	Task
Resolved	Krinkle	T96229 Creating MySQL tables for MediaWiki sometimes stalled on I/O for several minutes
Resolved	Krinkle	T95971 Apache on Jenkins slave takes over 30s to respond (QUnit/AJAX "Test timed out")
Resolved	Krinkle	T96249 MySQL tuning on CI slaves (tracking)
Resolved	Krinkle	T96230 Switch MySQL storage to tmpfs
Resolved	JanZerebecki	T126699 mediawiki jobs fail intermittently with "mw-teardown-mysql.sh: Can't revoke all privileges"
Declined	Krinkle	T96250 Tune MySQL innodb settings on CI slaves
Resolved	Krinkle	T96308 Evaluate using libeatmydata for mysqld

hashar created this task.Apr 16 2015, 2:30 PM

hashar raised the priority of this task from to Needs Triage.

hashar updated the task description. (Show Details)

hashar added projects: Continuous-Integration-Infrastructure, Tracking-Neverending.

hashar subscribed.

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hashar added a subtask: T96230: Switch MySQL storage to tmpfs.Apr 16 2015, 2:30 PM

hashar added a parent task: T96229: Creating MySQL tables for MediaWiki sometimes stalled on I/O for several minutes.

hashar added a parent task: T93556: Unit tests using database are slower than needed.

hashar added a parent task: T95971: Apache on Jenkins slave takes over 30s to respond (QUnit/AJAX "Test timed out").

hashar mentioned this in T96230: Switch MySQL storage to tmpfs.

Krinkle removed a parent task: T93556: Unit tests using database are slower than needed.Apr 16 2015, 2:36 PM

In addition to using tmpfs for the mysqld.datadir (T96230), there seems to be quite a lot of information online about using tmpfs for mysqld.tmpdir.

I'm not sure to what extent our use of MySQL involves it reaching out to the tmpdir, but considering that that is disk-bound on Ubuntu by default, we may want to create consider switching the mysql tmpdir to tmpfs as well. Let's try T96230 first, though.

In addition to mysql datadir and mysql tmpdir, another thing that I read a fair bit online is using engine=MEMORY. http://dev.mysql.com/doc/refman/5.5/en/memory-storage-engine.html

I imagine that with datadir on tmpfs, using the MEMORY engine shouldn't matter much though. I'd rather we stick to InnoDB and other engines for predictable behaviour.

hashar mentioned this in T93556: Unit tests using database are slower than needed.Apr 17 2015, 8:16 AM

I gave engine=MEMORY a quick try on https://gerrit.wikimedia.org/r/#/c/199633/ but eventually gave up because that engine does not support BLOB/TEXT columns so the installer fail initializing such tables (ex: user).

Krinkle triaged this task as Medium priority.Apr 17 2015, 12:17 PM

Krinkle set Security to None.

Krinkle moved this task from Untriaged to Backlog on the Continuous-Integration-Infrastructure board.

Krinkle closed subtask T96230: Switch MySQL storage to tmpfs as Resolved.Apr 17 2015, 3:48 PM

Krenair renamed this task from MySQL tunning on CI slaves (tracking) to MySQL tuning on CI slaves (tracking).Apr 21 2015, 4:53 PM

Krenair subscribed.

Krinkle closed subtask T96308: Evaluate using libeatmydata for mysqld as Resolved.Apr 21 2015, 6:37 PM

Ricordisamoa subscribed.Apr 21 2015, 7:17 PM

hashar lowered the priority of this task from Medium to Low.Oct 6 2015, 12:37 PM

Krinkle closed this task as Resolved.Feb 16 2016, 2:30 PM

Krinkle claimed this task.

Krinkle closed subtask T96250: Tune MySQL innodb settings on CI slaves as Declined.