For example, when I try to log in in beta labs:
[XQGFxqwQBHcAABxvtLIAAAAM] /wiki/Special:UserLogin Wikimedia\Rdbms\DBReadOnlyRoleError from line 1040 of /srv/mediawiki/php-master/includes/libs/rdbms/database/Database.php: Write operations are not allowed on replica database connections. Backtrace: #0 /srv/mediawiki/php-master/includes/libs/rdbms/database/Database.php(1249): Wikimedia\Rdbms\Database->assertIsWritableMaster() #1 /srv/mediawiki/php-master/includes/libs/rdbms/database/DatabaseMysqlBase.php(248): Wikimedia\Rdbms\Database->executeQuery(string, string, integer) #2 /srv/mediawiki/php-master/includes/libs/rdbms/database/Database.php(2412): Wikimedia\Rdbms\DatabaseMysqlBase->doSelectDomain(Wikimedia\Rdbms\DatabaseDomain) #3 /srv/mediawiki/php-master/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1036): Wikimedia\Rdbms\Database->selectDomain(Wikimedia\Rdbms\DatabaseDomain) #4 /srv/mediawiki/php-master/includes/libs/rdbms/loadbalancer/LoadBalancer.php(890): Wikimedia\Rdbms\LoadBalancer->openForeignConnection(integer, string, integer) #5 /srv/mediawiki/php-master/includes/libs/rdbms/loadbalancer/LoadBalancer.php(763): Wikimedia\Rdbms\LoadBalancer->openConnection(integer, string, integer) #6 /srv/mediawiki/php-master/includes/libs/rdbms/loadbalancer/LoadBalancer.php(850): Wikimedia\Rdbms\LoadBalancer->getConnection(integer, array, string, integer) #7 /srv/mediawiki/php-master/extensions/CentralAuth/includes/CentralAuthUser.php(2485): Wikimedia\Rdbms\LoadBalancer->getConnectionRef(integer, array, string) #8 /srv/mediawiki/php-master/extensions/CentralAuth/includes/CentralAuthUser.php(2381): CentralAuthUser->localUserData(string) #9 /srv/mediawiki/php-master/extensions/CentralAuth/includes/CentralAuthUser.php(2354): CentralAuthUser->queryAttached() #10 /srv/mediawiki/php-master/extensions/CentralAuth/includes/CentralAuthHooks.php(1433): CentralAuthUser->getLocalGroups() #11 /srv/mediawiki/php-master/includes/Hooks.php(174): CentralAuthHooks::onPasswordPoliciesForUser(User, array) #12 /srv/mediawiki/php-master/includes/Hooks.php(202): Hooks::callHook(string, array, array, NULL) #13 /srv/mediawiki/php-master/includes/password/UserPasswordPolicy.php(180): Hooks::run(string, array) #14 /srv/mediawiki/php-master/includes/password/UserPasswordPolicy.php(77): UserPasswordPolicy->getPoliciesForUser(User) #15 /srv/mediawiki/php-master/includes/user/User.php(1208): UserPasswordPolicy->checkUserPassword(User, string) #16 /srv/mediawiki/php-master/includes/auth/AbstractPasswordPrimaryAuthenticationProvider.php(106): User->checkPasswordValidity(string) #17 /srv/mediawiki/php-master/includes/auth/TemporaryPasswordPrimaryAuthenticationProvider.php(142): MediaWiki\Auth\AbstractPasswordPrimaryAuthenticationProvider->checkPasswordValidity(string, string) #18 /srv/mediawiki/php-master/includes/auth/AuthManager.php(455): MediaWiki\Auth\TemporaryPasswordPrimaryAuthenticationProvider->beginPrimaryAuthentication(array) #19 /srv/mediawiki/php-master/includes/auth/AuthManager.php(385): MediaWiki\Auth\AuthManager->continueAuthentication(array) #20 /srv/mediawiki/php-master/includes/specialpage/AuthManagerSpecialPage.php(353): MediaWiki\Auth\AuthManager->beginAuthentication(array, string) #21 /srv/mediawiki/php-master/includes/specialpage/AuthManagerSpecialPage.php(482): AuthManagerSpecialPage->performAuthenticationStep(string, array) #22 /srv/mediawiki/php-master/includes/htmlform/HTMLForm.php(672): AuthManagerSpecialPage->handleFormSubmit(array, VFormHTMLForm) #23 /srv/mediawiki/php-master/includes/specialpage/AuthManagerSpecialPage.php(416): HTMLForm->trySubmit() #24 /srv/mediawiki/php-master/includes/specialpage/LoginSignupSpecialPage.php(313): AuthManagerSpecialPage->trySubmit() #25 /srv/mediawiki/php-master/includes/specialpage/SpecialPage.php(571): LoginSignupSpecialPage->execute(NULL) #26 /srv/mediawiki/php-master/includes/specialpage/SpecialPageFactory.php(575): SpecialPage->run(NULL) #27 /srv/mediawiki/php-master/includes/MediaWiki.php(288): MediaWiki\Special\SpecialPageFactory->executePath(Title, RequestContext) #28 /srv/mediawiki/php-master/includes/MediaWiki.php(865): MediaWiki->performRequest() #29 /srv/mediawiki/php-master/includes/MediaWiki.php(515): MediaWiki->main() #30 /srv/mediawiki/php-master/index.php(42): MediaWiki->run() #31 /srv/mediawiki/w/index.php(3): include(string) #32 {main}