==== Error ====
* mwversion: `1.37.0-wmf.1`
* reqId: `4cf732a0-9c93-4165-a255-bf562dcb8d83`
* [[ https://logstash.wikimedia.org/app/dashboards#/view/AXFV7JE83bOlOASGccsT?_g=(time:(from:'2021-04-12T21:28:45.000Z',to:'2021-04-13T21:30:15.171Z'))&_a=(query:(query_string:(query:'reqId:%224cf732a0-9c93-4165-a255-bf562dcb8d83%22'))) | Find reqId in Logstash ]]
* [[ https://logstash.wikimedia.org/app/dashboards#/view/AXFV7JE83bOlOASGccsT?_g=(time:(from:now-30d,to:now))&_a=(query:(query_string:(query:'normalized_message:%22%5B%7BreqId%7D%5D%20%7Bexception_url%7D%20%20%20Wikimedia%5CRdbms%5CDBQueryError:%20Error%201146:%20Table%20'mediawikiwiki.discussiontools_subscription'%20doesn't%20exist%20(10.64.16.7)%0AFunction:%20MediaWiki%5CExtension%5CDiscussionTools%5CSubscriptionStore::fetchSubscriptions%0AQuery:%20SELECT%20%20sub_user%22'))) | Find normalized_message in Logstash ]]
```name=normalized_message
[{reqId}] {exception_url} Wikimedia\Rdbms\DBQueryError: Error 1146: Table 'mediawikiwiki.discussiontools_subscription' doesn't exist (10.64.16.7)
Function: MediaWiki\Extension\DiscussionTools\SubscriptionStore::fetchSubscriptions
Query: SELECT sub_user
```
```name=exception.trace,lines=10
from /srv/mediawiki/php-1.37.0-wmf.1/includes/libs/rdbms/database/Database.php(1738)
#0 /srv/mediawiki/php-1.37.0-wmf.1/includes/libs/rdbms/database/Database.php(1722): Wikimedia\Rdbms\Database->getQueryException(string, integer, string, string)
#1 /srv/mediawiki/php-1.37.0-wmf.1/includes/libs/rdbms/database/Database.php(1697): Wikimedia\Rdbms\Database->getQueryExceptionAndLog(string, integer, string, string)
#2 /srv/mediawiki/php-1.37.0-wmf.1/includes/libs/rdbms/database/Database.php(1260): Wikimedia\Rdbms\Database->reportQueryError(string, integer, string, string, boolean)
#3 /srv/mediawiki/php-1.37.0-wmf.1/includes/libs/rdbms/database/Database.php(1948): Wikimedia\Rdbms\Database->query(string, string, integer)
#4 /srv/mediawiki/php-1.37.0-wmf.1/includes/libs/rdbms/database/DBConnRef.php(68): Wikimedia\Rdbms\Database->select(string, array, array, string)
#5 /srv/mediawiki/php-1.37.0-wmf.1/includes/libs/rdbms/database/DBConnRef.php(313): Wikimedia\Rdbms\DBConnRef->__call(string, array)
#6 /srv/mediawiki/php-1.37.0-wmf.1/extensions/DiscussionTools/includes/SubscriptionStore.php(92): Wikimedia\Rdbms\DBConnRef->select(string, array, array, string)
#7 /srv/mediawiki/php-1.37.0-wmf.1/extensions/DiscussionTools/includes/SubscriptionStore.php(121): MediaWiki\Extension\DiscussionTools\SubscriptionStore->fetchSubscriptions(Wikimedia\Rdbms\DBConnRef, User, string, NULL)
#8 /srv/mediawiki/php-1.37.0-wmf.1/extensions/DiscussionTools/includes/Hooks/PageHooks.php(138): MediaWiki\Extension\DiscussionTools\SubscriptionStore->getSubscriptionItemsForUser(User, string)
#9 [internal function]: MediaWiki\Extension\DiscussionTools\Hooks\PageHooks->MediaWiki\Extension\DiscussionTools\Hooks\{closure}(array)
#10 /srv/mediawiki/php-1.37.0-wmf.1/extensions/DiscussionTools/includes/Hooks/PageHooks.php(150): preg_replace_callback(string, Closure, string)
#11 /srv/mediawiki/php-1.37.0-wmf.1/includes/HookContainer/HookContainer.php(160): MediaWiki\Extension\DiscussionTools\Hooks\PageHooks->onOutputPageBeforeHTML(OutputPage, string)
#12 /srv/mediawiki/php-1.37.0-wmf.1/includes/HookContainer/HookRunner.php(2762): MediaWiki\HookContainer\HookContainer->run(string, array)
#13 /srv/mediawiki/php-1.37.0-wmf.1/includes/OutputPage.php(2007): MediaWiki\HookContainer\HookRunner->onOutputPageBeforeHTML(OutputPage, string)
#14 /srv/mediawiki/php-1.37.0-wmf.1/includes/OutputPage.php(2019): OutputPage->addParserOutputText(ParserOutput, array)
#15 /srv/mediawiki/php-1.37.0-wmf.1/includes/page/Article.php(796): OutputPage->addParserOutput(ParserOutput, array)
#16 /srv/mediawiki/php-1.37.0-wmf.1/includes/page/Article.php(654): Article->doOutputFromParserCache(ParserOutput, OutputPage, array)
#17 /srv/mediawiki/php-1.37.0-wmf.1/includes/page/Article.php(561): Article->generateContentOutput(User, ParserOptions, integer, OutputPage, array)
#18 /srv/mediawiki/php-1.37.0-wmf.1/includes/actions/ViewAction.php(74): Article->view()
#19 /srv/mediawiki/php-1.37.0-wmf.1/includes/MediaWiki.php(535): ViewAction->show()
#20 /srv/mediawiki/php-1.37.0-wmf.1/includes/MediaWiki.php(319): MediaWiki->performAction(Article, Title)
#21 /srv/mediawiki/php-1.37.0-wmf.1/includes/MediaWiki.php(916): MediaWiki->performRequest()
#22 /srv/mediawiki/php-1.37.0-wmf.1/includes/MediaWiki.php(550): MediaWiki->main()
#23 /srv/mediawiki/php-1.37.0-wmf.1/index.php(53): MediaWiki->run()
#24 /srv/mediawiki/php-1.37.0-wmf.1/index.php(46): wfIndexMain()
#25 /srv/mediawiki/w/index.php(3): require(string)
#26 {main}
```
==== Impact ====
MediaWiki.org cannot be accessed by people with discussiontools enabled (try appending ?dtenable=1 to reproduce).
==== Notes ====