Make the WikiProject or Page title field required for Page Assessments
Closed, ResolvedPublic3 Estimated Story Points
Actions

Description

On Page Assessments, you need to fill in either the WikiProject field or the Page title field before clicking Search. There's no use case that would require just searching for a namespace without WikiProject or Page title.

When a user clicks Search without filling in at least one of the other fields, don't run a query. Just display a red warning: "WikiProject or Page title field required"

Also make sure that the results are ordered alphabetically.

Also, this will probably mean that we don't want to have the page do a default query at all when you first load the page.

Details

	Subject	Repo	Branch	Lines +/-
	Only execute query under specific circumstances to prevent timeouts	mediawiki/extensions/PageAssessments	master	+21 -5
	Disallow slow query when filtering only by namespace	mediawiki/extensions/PageAssessments	master	+21 -10

Customize query in gerrit

Related Objects

Mentioned Here: T33197: Implement revision filter by namespace for big wikis in "miser mode"
T168600: Special:PageAssessments with specified limit is off by one
P5614 WUs7oQpAMFAAAAG5QqEAAABN query

Event Timeline

TheDragonFire created this task.Jun 22 2017, 3:33 AM

Restricted Application added a subscriber: Aklapper. · View Herald TranscriptJun 22 2017, 3:33 AM

• MZMcBride subscribed.Jun 22 2017, 3:39 AM

bd808 found this:

P5614 WUs7oQpAMFAAAAG5QqEAAABN query

1	SELECT pap_project_title AS `project`,
2	pa_class AS `class`,
3	pa_importance AS `importance`,
4	rev_timestamp AS `timestamp`,
5	page_title,pa_page_revision AS `page_revision`,
6	page_namespace
7	FROM `page_assessments`
8	JOIN `page_assessments_projects` ON ((pa_project_id = pap_project_id))
9	JOIN `page` ON ((pa_page_id = page_id))
10	JOIN `revision` ON ((page_id = rev_page AND pa_page_revision = rev_id))
11	WHERE page_namespace = '2' LIMIT 101

https://en.wikipedia.org/wiki/Special:PageAssessments?project=&namespace=2&page_title= is working now. It was failing before. My guess is that the data warmed up a bit.

https://en.wikipedia.org/wiki/Special:PageAssessments?project=&namespace=2&page_title=&limit=1 returns faster (though with an off-by-one error?). Broadly, the errors may be a pagination issue, where there's a large data set and "obscure" namespaces cause a lot of row scanning, which often results in queries getting killed (timing out) for exceeding a maximum execution time. I believe we still have this issue with (for example) Special:Contributions for users with lots of edits, when you try to filter to uncommon namespaces with a high per-page result set limit.

Original exception was:

Wikimedia\Rdbms\Database::query: lost connection to 10.64.48.20; reconnected:
#0 /srv/mediawiki/php-1.30.0-wmf.5/includes/libs/rdbms/database/Database.php(2905): Wikimedia\Rdbms\Database->query()
#1 /srv/mediawiki/php-1.30.0-wmf.5/includes/libs/rdbms/database/Database.php(2881): Wikimedia\Rdbms\Database->doCommit()
#2 /srv/mediawiki/php-1.30.0-wmf.5/includes/libs/rdbms/database/Database.php(756): Wikimedia\Rdbms\Database->commit()
#3 /srv/mediawiki/php-1.30.0-wmf.5/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1084): Wikimedia\Rdbms\Database->close()
#4 (): Closure$Wikimedia\Rdbms\LoadBalancer::closeAll()
#5 /srv/mediawiki/php-1.30.0-wmf.5/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1485): call_user_func_array()
#6 /srv/mediawiki/php-1.30.0-wmf.5/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1085): Wikimedia\Rdbms\LoadBalancer->forEachOpenConnection()
#7 /srv/mediawiki/php-1.30.0-wmf.5/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1076): Wikimedia\Rdbms\LoadBalancer->closeAll()
#8 /srv/mediawiki/php-1.30.0-wmf.5/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1665): Wikimedia\Rdbms\LoadBalancer->disable()
#9 (): Wikimedia\Rdbms\LoadBalancer->__destruct()
#10 {main}

https://en.wikipedia.org/wiki/Special:PageAssessments?project=&namespace=3&page_title=&limit=4 resulted in:

[WUtF3ApAEK8AAECsXNcAAABR] 2017-06-22 04:22:48: Fatal exception of type "Wikimedia\Rdbms\DBQueryError"

MariaDB [enwiki_p]> select count(*) from page_assessments;
+----------+
| count(*) |
+----------+
| 16787476 |
+----------+
1 row in set (16.25 sec)

Decent number of rows. But, without any joins, it was able to scan them all pretty quickly on the replica database. Hmmm.

In T168599#3369504, @MZMcBride wrote:

https://en.wikipedia.org/wiki/Special:PageAssessments?project=&namespace=2&page_title=&limit=1 returns faster (though with an off-by-one error?).

Filed as T168600: Special:PageAssessments with specified limit is off by one.

Broadly, the errors may be a pagination issue, where there's a large data set and "obscure" namespaces cause a lot of row scanning, which often results in queries getting killed (timing out) for exceeding a maximum execution time. I believe we still have this issue with (for example) Special:Contributions for users with lots of edits, when you try to filter to uncommon namespaces with a high per-page result set limit.

This is mostly referring to T33197#356905.

Confirmed the bug.

Maybe we should restrict it to require a project or title.

• DannyH renamed this task from PageAssessments search for specific namespace yields DB error in one circumstance to Make the WikiProject or Page title field required for Page Assessments.Jun 27 2017, 11:17 PM

• DannyH updated the task description. (Show Details)

kaldari triaged this task as Medium priority.Jun 27 2017, 11:24 PM

kaldari updated the task description. (Show Details)

kaldari set the point value for this task to 3.

• DannyH moved this task from Needs Discussion to Up Next (June 3-21) on the Community-Tech board.Jun 27 2017, 11:26 PM

MaxSem claimed this task.Jul 11 2017, 10:02 PM

MaxSem added a project: Community-Tech-Sprint.

Change 364635 had a related patch set uploaded (by MaxSem; owner: MaxSem):
[mediawiki/extensions/PageAssessments@master] Disallow slow query when filtering only by namespace

https://gerrit.wikimedia.org/r/364635

gerritbot added a project: Patch-For-Review.Jul 12 2017, 1:58 AM

MaxSem moved this task from Ready to Needs Review/Feedback on the Community-Tech-Sprint board.Jul 12 2017, 1:59 AM

Change 364635 merged by jenkins-bot:
[mediawiki/extensions/PageAssessments@master] Disallow slow query when filtering only by namespace

https://gerrit.wikimedia.org/r/364635

ReleaseTaggerBot added a project: MW-1.30-release-notes (WMF-deploy-2017-07-18_(1.30.0-wmf.10)).Jul 12 2017, 8:00 AM

Niharika removed a project: Community-Tech.Jul 12 2017, 8:52 PM

Niharika moved this task from Needs Review/Feedback to Q1 2018-19 on the Community-Tech-Sprint board.

This isn't exactly the solution requested in the description, but it's pretty close. Since Special:PageAssessments is a QueryPage, it would actually take some refactoring to prevent it from doing a default query. The current solution seems like a good improvement though. If anyone feels strongly that we should just get rid of the default query entirely, feel free to reopen.

• DannyH edited projects, added Community-Tech; removed Community-Tech-Sprint.Jul 18 2017, 10:39 PM

• DannyH moved this task from Up Next (June 3-21) to Archive on the Community-Tech board.Jul 18 2017, 10:47 PM

MusikAnimal moved this task from Backlog to Done on the MediaWiki-extensions-PageAssessments board.Apr 4 2018, 6:58 PM

Change 587399 had a related patch set uploaded (by Kaldari; owner: Kaldari):
[mediawiki/extensions/PageAssessments@master] Only execute query under specific circumstances to prevent timeouts

https://gerrit.wikimedia.org/r/587399

Change 587399 merged by jenkins-bot:
[mediawiki/extensions/PageAssessments@master] Only execute query under specific circumstances to prevent timeouts