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Backtrace:
#0 /opt/mediawiki/w/includes/libs/rdbms/loadbalancer/LoadBalancer.php(937): Wikimedia\Rdbms\LoadBalancer->reportConnectionError()
#1 /opt/mediawiki/w/includes/libs/rdbms/loadbalancer/LoadBalancer.php(904): Wikimedia\Rdbms\LoadBalancer->getServerConnection()
#2 /opt/mediawiki/w/extensions/KeycloakAuth/src/KeycloakIntegration.php(122): Wikimedia\Rdbms\LoadBalancer->getConnection()
#3 /opt/mediawiki/w/extensions/KeycloakAuth/src/KeycloakIntegration.php(74): KeycloakAuth\KeycloakIntegration->extractVars()
#4 /opt/mediawiki/w/extensions/KeycloakAuth/src/Setup.php(30): KeycloakAuth\KeycloakIntegration->getUsername()
#5 [internal function]: KeycloakAuth\Setup::KeycloakAuth\{closure}()
#6 /opt/mediawiki/w/extensions/Auth_remoteuser/src/UserNameSessionProvider.php(268): call_user_func()
#7 /opt/mediawiki/w/includes/session/SessionManager.php(490): MediaWiki\Extension\Auth_remoteuser\UserNameSessionProvider->provideSessionInfo()
#8 /opt/mediawiki/w/includes/session/SessionManager.php(215): MediaWiki\Session\SessionManager->getSessionInfoForRequest()
#9 /opt/mediawiki/w/includes/WebRequest.php(826): MediaWiki\Session\SessionManager->getSessionForRequest()
#10 /opt/mediawiki/w/includes/session/SessionManager.php(137): WebRequest->getSession()
#11 /opt/mediawiki/w/includes/Setup.php(725): MediaWiki\Session\SessionManager::getGlobalSession()
#12 /opt/mediawiki/w/includes/WebStart.php(89): require_once('/opt/mediawiki/...')
#13 /opt/mediawiki/w/index.php(44): require('/opt/mediawiki/...')
#14 {main}