ApiLogin does not have the write mode flag set (and it shouldn't), so when it opens a master connection (via CentralAuth by way of AuthManager) this causes a warning.
Expectation (masterConns <= 0) by ApiMain::setRequestExpectations not met:
[connect to 10.64.16.30 (centralauth)]
#0 /srv/mediawiki/php-1.29.0-wmf.6/includes/libs/rdbms/TransactionProfiler.php(160): TransactionProfiler->reportExpectationViolated()
#1 /srv/mediawiki/php-1.29.0-wmf.6/includes/libs/rdbms/loadbalancer/LoadBalancer.php(587): TransactionProfiler->recordConnection()
#2 /srv/mediawiki/php-1.29.0-wmf.6/extensions/CentralAuth/includes/CentralAuthUtils.php(53): LoadBalancer->getConnection()
#3 /srv/mediawiki/php-1.29.0-wmf.6/extensions/CentralAuth/includes/CentralAuthUser.php(228): CentralAuthUtils::getCentralDB()
#4 /srv/mediawiki/php-1.29.0-wmf.6/extensions/CentralAuth/includes/CentralAuthUser.php(416): CentralAuthUser->getSafeReadDB()
#5 /srv/mediawiki/php-1.29.0-wmf.6/extensions/CentralAuth/includes/CentralAuthUser.php(359): CentralAuthUser->loadFromDatabase()
#6 /srv/mediawiki/php-1.29.0-wmf.6/extensions/CentralAuth/includes/CentralAuthUser.php(532): CentralAuthUser->loadState()
#7 /srv/mediawiki/php-1.29.0-wmf.6/extensions/CentralAuth/includes/CentralAuthUser.php(1843): CentralAuthUser->getId()
#8 /srv/mediawiki/php-1.29.0-wmf.6/extensions/CentralAuth/includes/CentralAuthUser.php(1878): CentralAuthUser->canAuthenticate()
#9 /srv/mediawiki/php-1.29.0-wmf.6/extensions/CentralAuth/includes/CentralAuthPrimaryAuthenticationProvider.php(128): CentralAuthUser->authenticate()
#10 /srv/mediawiki/php-1.29.0-wmf.6/includes/auth/AuthManager.php(452): CentralAuthPrimaryAuthenticationProvider->beginPrimaryAuthentication()
#11 /srv/mediawiki/php-1.29.0-wmf.6/includes/auth/AuthManager.php(382): MediaWiki\Auth\AuthManager->continueAuthentication()
#12 /srv/mediawiki/php-1.29.0-wmf.6/includes/api/ApiLogin.php(146): MediaWiki\Auth\AuthManager->beginAuthentication()
#13 /srv/mediawiki/php-1.29.0-wmf.6/includes/api/ApiMain.php(1532): ApiLogin->execute()
#14 /srv/mediawiki/php-1.29.0-wmf.6/includes/api/ApiMain.php(541): ApiMain->executeAction()
#15 /srv/mediawiki/php-1.29.0-wmf.6/includes/api/ApiMain.php(512): ApiMain->executeActionWithErrorHandling()
#16 /srv/mediawiki/php-1.29.0-wmf.6/api.php(83): ApiMain->execute()
#17 /srv/mediawiki/w/api.php(3): include()
#18 {main}@aaron opined on IRC that:
17:09:23 <+AaronSchulz> the lazy import of local names should just be fixed/migrated and the password hash updates should silence the warnings via setSilenced() or the like 17:09:41 <+AaronSchulz> but, yes, it should not have write mode
See also: