MediaWiki internal error.

Original exception: [032c02a68ccfff4e0b08fa02] /index.php?title=Naufrage_de_la_Blanche-Nef_(1120)&diff=453845&oldid=91138 Wikimedia\Rdbms\DBConnectionError: Cannot access the database: Too many connections (localhost)
Backtrace:
from /var/www/html/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1149)
#0 /var/www/html/includes/libs/rdbms/loadbalancer/LoadBalancer.php(805): Wikimedia\Rdbms\LoadBalancer->reportConnectionError()
#1 /var/www/html/includes/libs/rdbms/loadbalancer/LoadBalancer.php(793): Wikimedia\Rdbms\LoadBalancer->getServerConnection()
#2 /var/www/html/includes/libs/rdbms/database/DBConnRef.php(103): Wikimedia\Rdbms\LoadBalancer->getConnectionInternal()
#3 /var/www/html/includes/libs/rdbms/database/DBConnRef.php(117): Wikimedia\Rdbms\DBConnRef->ensureConnection()
#4 /var/www/html/includes/libs/rdbms/database/DBConnRef.php(369): Wikimedia\Rdbms\DBConnRef->__call()
#5 /var/www/html/includes/libs/rdbms/querybuilder/SelectQueryBuilder.php(756): Wikimedia\Rdbms\DBConnRef->selectRow()
#6 /var/www/html/includes/Revision/RevisionStore.php(2421): Wikimedia\Rdbms\SelectQueryBuilder->fetchRow()
#7 /var/www/html/includes/Revision/RevisionStore.php(2366): MediaWiki\Revision\RevisionStore->fetchRevisionRowFromConds()
#8 /var/www/html/includes/Revision/RevisionStore.php(2328): MediaWiki\Revision\RevisionStore->loadRevisionFromConds()
#9 /var/www/html/includes/Revision/RevisionStore.php(1258): MediaWiki\Revision\RevisionStore->newRevisionFromConds()
#10 /var/www/html/includes/MediaWiki.php(131): MediaWiki\Revision\RevisionStore->getRevisionById()
#11 /var/www/html/includes/MediaWiki.php(189): MediaWiki->parseTitle()
#12 /var/www/html/includes/MediaWiki.php(908): MediaWiki->getTitle()
#13 /var/www/html/includes/MediaWiki.php(613): MediaWiki->main()
#14 /var/www/html/index.php(50): MediaWiki->run()
#15 /var/www/html/index.php(46): wfIndexMain()
#16 {main}

Exception caught inside exception handler: [032c02a68ccfff4e0b08fa02] /index.php?title=Naufrage_de_la_Blanche-Nef_(1120)&diff=453845&oldid=91138 Wikimedia\Rdbms\DBConnectionError: Cannot access the database: Too many connections (localhost)
Backtrace:
from /var/www/html/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1149)
#0 /var/www/html/includes/libs/rdbms/loadbalancer/LoadBalancer.php(805): Wikimedia\Rdbms\LoadBalancer->reportConnectionError()
#1 /var/www/html/includes/libs/rdbms/loadbalancer/LoadBalancer.php(793): Wikimedia\Rdbms\LoadBalancer->getServerConnection()
#2 /var/www/html/includes/libs/rdbms/database/DBConnRef.php(103): Wikimedia\Rdbms\LoadBalancer->getConnectionInternal()
#3 /var/www/html/includes/libs/rdbms/database/DBConnRef.php(117): Wikimedia\Rdbms\DBConnRef->ensureConnection()
#4 /var/www/html/includes/libs/rdbms/database/DBConnRef.php(710): Wikimedia\Rdbms\DBConnRef->__call()
#5 /var/www/html/includes/libs/rdbms/database/Database.php(2760): Wikimedia\Rdbms\DBConnRef->getSessionLagStatus()
#6 /var/www/html/extensions/Gadgets/includes/MediaWikiGadgetsDefinitionRepo.php(119): Wikimedia\Rdbms\Database::getCacheSetOptions()
#7 /var/www/html/includes/libs/objectcache/wancache/WANObjectCache.php(1726): MediaWiki\Extension\Gadgets\MediaWikiGadgetsDefinitionRepo->MediaWiki\Extension\Gadgets\{closure}()
#8 /var/www/html/includes/libs/objectcache/wancache/WANObjectCache.php(1556): WANObjectCache->fetchOrRegenerate()
#9 /var/www/html/extensions/Gadgets/includes/MediaWikiGadgetsDefinitionRepo.php(124): WANObjectCache->getWithSetCallback()
#10 /var/www/html/includes/libs/objectcache/BagOStuff.php(206): MediaWiki\Extension\Gadgets\MediaWikiGadgetsDefinitionRepo->MediaWiki\Extension\Gadgets\{closure}()
#11 /var/www/html/extensions/Gadgets/includes/MediaWikiGadgetsDefinitionRepo.php(129): BagOStuff->getWithSetCallback()
#12 /var/www/html/extensions/Gadgets/includes/MediaWikiGadgetsDefinitionRepo.php(42): MediaWiki\Extension\Gadgets\MediaWikiGadgetsDefinitionRepo->loadGadgets()
#13 /var/www/html/extensions/Gadgets/includes/GadgetRepo.php(70): MediaWiki\Extension\Gadgets\MediaWikiGadgetsDefinitionRepo->getGadgetIds()
#14 /var/www/html/extensions/Gadgets/includes/Hooks.php(133): MediaWiki\Extension\Gadgets\GadgetRepo->getStructuredList()
#15 /var/www/html/includes/HookContainer/HookContainer.php(161): MediaWiki\Extension\Gadgets\Hooks->onUserGetDefaultOptions()
#16 /var/www/html/includes/HookContainer/HookRunner.php(4196): MediaWiki\HookContainer\HookContainer->run()
#17 /var/www/html/includes/user/DefaultOptionsLookup.php(117): MediaWiki\HookContainer\HookRunner->onUserGetDefaultOptions()
#18 /var/www/html/includes/user/UserOptionsManager.php(598): MediaWiki\User\DefaultOptionsLookup->getDefaultOptions()
#19 /var/www/html/includes/user/UserOptionsManager.php(501): MediaWiki\User\UserOptionsManager->loadOriginalOptions()
#20 /var/www/html/includes/user/UserOptionsManager.php(147): MediaWiki\User\UserOptionsManager->loadUserOptions()
#21 /var/www/html/includes/context/RequestContext.php(459): MediaWiki\User\UserOptionsManager->getOption()
#22 /var/www/html/includes/language/Message.php(389): RequestContext->getLanguage()
#23 /var/www/html/includes/language/Message.php(1485): Message->getLanguage()
#24 /var/www/html/includes/language/Message.php(972): Message->fetchMessage()
#25 /var/www/html/includes/language/Message.php(1059): Message->format()
#26 /var/www/html/includes/exception/MWExceptionRenderer.php(254): Message->text()
#27 /var/www/html/includes/exception/MWExceptionRenderer.php(400): MWExceptionRenderer::msg()
#28 /var/www/html/includes/exception/MWExceptionRenderer.php(103): MWExceptionRenderer::reportOutageHTML()
#29 /var/www/html/includes/exception/MWExceptionHandler.php(134): MWExceptionRenderer::output()
#30 /var/www/html/includes/exception/MWExceptionHandler.php(251): MWExceptionHandler::report()
#31 /var/www/html/includes/MediaWiki.php(632): MWExceptionHandler::handleException()
#32 /var/www/html/index.php(50): MediaWiki->run()
#33 /var/www/html/index.php(46): wfIndexMain()
#34 {main}