Error
Request ID: W9tWQQpAMEAAAKXLgKIAAADJ
message
A database query error has occurred. [..] Query: UPDATE `watchlist` SET wl_notificationtimestamp = NULL WHERE wl_user = '#######' Function: WatchedItemStore::setNotificationTimestampsForUser Error: 1205 Lock wait timeout exceeded; try restarting transaction channel: exception exception.class: Wikimedia\Rdbms\DBQueryError
trace
#3 /srv/mediawiki/php-1.33.0-wmf.1/includes/libs/rdbms/database/DBConnRef.php(49): Wikimedia\Rdbms\Database->update(string, array, array, string) #4 /srv/mediawiki/php-1.33.0-wmf.1/includes/libs/rdbms/database/DBConnRef.php(313): Wikimedia\Rdbms\DBConnRef->__call(string, array) #5 /srv/mediawiki/php-1.33.0-wmf.1/includes/watcheditem/WatchedItemStore.php(805): Wikimedia\Rdbms\DBConnRef->update(string, array, array, string) #6 /srv/mediawiki/php-1.33.0-wmf.1/includes/api/ApiSetNotificationTimestamp.php(114): WatchedItemStore->setNotificationTimestampsForUser(User, NULL) #7 /srv/mediawiki/php-1.33.0-wmf.1/includes/api/ApiMain.php(1570): ApiSetNotificationTimestamp->execute() #8 /srv/mediawiki/php-1.33.0-wmf.1/includes/api/ApiMain.php(531): ApiMain->executeAction() #9 /srv/mediawiki/php-1.33.0-wmf.1/includes/api/ApiMain.php(502): ApiMain->executeActionWithErrorHandling() #10 /srv/mediawiki/php-1.33.0-wmf.1/api.php(87): ApiMain->execute() #11 /srv/mediawiki/w/api.php(3): include(string)
Impact
The user action is aborted with a fatal exception.
In this case the "Reset" button on the user's Watchlist that is meant to mark all changes as "read", fails with a fatal error (not shown to the user when JavaScript is disabled). After which the user can try it again without JavaScript and may or may not fail again (this time with technical fatal exception shown to the user without further instructions or details).
Notes
The following errors are similar in nature (resultant from the same kind of code problem) but are in different code paths and triggered by different user actions, as such as separate task was created. It is likely that whatever approach is taken by the others might be applicable here as well: