Failed to connect to the database, Connection timed out (latest nextcloud and mariadb:10.5)

[panomitrius]

Been using nextcloud docker for some time now, and it's been working great until today.

Running Ubuntu 20.04.3 LTS with Docker version 20.10.12, build e91ed57. Using the latest nextcloud docker image with mariadb:10.5.

I get the following error message from the log.

An unhandled exception has been thrown:
Doctrine\DBAL\Exception: Failed to connect to the database: An exception occurred in the driver: SQLSTATE[HY000] [2002] Connection timed out in /var/www/html/lib/private/DB/Connection.php:87
Stack trace:
#0 /var/www/html/3rdparty/doctrine/dbal/src/Connection.php(1519): OC\DB\Connection->connect()
#1 /var/www/html/3rdparty/doctrine/dbal/src/Connection.php(1041): Doctrine\DBAL\Connection->getWrappedConnection()
#2 /var/www/html/lib/private/DB/Connection.php(236): Doctrine\DBAL\Connection->executeQuery('SELECT * FROM `...', Array, Array, NULL)
#3 /var/www/html/3rdparty/doctrine/dbal/src/Query/QueryBuilder.php(345): OC\DB\Connection->executeQuery('SELECT * FROM `...', Array, Array)
#4 /var/www/html/lib/private/DB/QueryBuilder/QueryBuilder.php(287): Doctrine\DBAL\Query\QueryBuilder->execute()
#5 /var/www/html/lib/private/AppConfig.php(344): OC\DB\QueryBuilder\QueryBuilder->execute()
#6 /var/www/html/lib/private/AppConfig.php(109): OC\AppConfig->loadConfigValues()
#7 /var/www/html/lib/private/AppConfig.php(300): OC\AppConfig->getApps()
#8 /var/www/html/lib/private/legacy/OC_App.php(972): OC\AppConfig->getValues(false, 'installed_versi...')
#9 /var/www/html/lib/private/Server.php(691): OC_App::getAppVersions()
#10 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(160): OC\Server->OC\{closure}(Object(OC\Server))
#11 /var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#12 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(127): Pimple\Container->offsetGet('OC\\Memcache\\Fac...')
#13 /var/www/html/lib/private/ServerContainer.php(136): OC\AppFramework\Utility\SimpleContainer->query('OC\\Memcache\\Fac...', false)
#14 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(56): OC\ServerContainer->query('OC\\Memcache\\Fac...')
#15 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(182): OC\AppFramework\Utility\SimpleContainer->get('OC\\Memcache\\Fac...')
#16 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(160): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(OC\Server))
#17 /var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php(114): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#18 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(127): Pimple\Container->offsetGet('OCP\\ICacheFacto...')
#19 /var/www/html/lib/private/ServerContainer.php(136): OC\AppFramework\Utility\SimpleContainer->query('OCP\\ICacheFacto...', false)
#20 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(56): OC\ServerContainer->query('OCP\\ICacheFacto...')
#21 /var/www/html/lib/private/Server.php(1069): OC\AppFramework\Utility\SimpleContainer->get('OCP\\ICacheFacto...')
#22 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(160): OC\Server->OC\{closure}(Object(OC\Server))
#23 /var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#24 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(127): Pimple\Container->offsetGet('OCP\\Lock\\ILocki...')
#25 /var/www/html/lib/private/ServerContainer.php(136): OC\AppFramework\Utility\SimpleContainer->query('OCP\\Lock\\ILocki...', false)
#26 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(56): OC\ServerContainer->query('OCP\\Lock\\ILocki...')
#27 /var/www/html/lib/private/Server.php(2030): OC\AppFramework\Utility\SimpleContainer->get('OCP\\Lock\\ILocki...')
#28 /var/www/html/lib/private/Files/View.php(118): OC\Server->getLockingProvider()
#29 /var/www/html/lib/private/Server.php(439): OC\Files\View->__construct()
#30 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(160): OC\Server->OC\{closure}(Object(OC\Server))
#31 /var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#32 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(127): Pimple\Container->offsetGet('OC\\Files\\Node\\H...')
#33 /var/www/html/lib/private/ServerContainer.php(136): OC\AppFramework\Utility\SimpleContainer->query('OC\\Files\\Node\\H...', false)
#34 /var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php(56): OC\ServerContainer->query('OC\\Files\\Node\\H...')
#35 /var/www/html/lib/private/Server.php(1393): OC\AppFramework\Utility\SimpleContainer->get('OC\\Files\\Node\\H...')
#36 /var/www/html/lib/base.php(594): OC\Server->boot()
#37 /var/www/html/lib/base.php(1087): OC::init()
#38 /var/www/html/console.php(48): require_once('/var/www/html/l...')
#39 /var/www/html/occ(11): require_once('/var/www/html/c...')

[panomitrius]

Started working after 8 or so restarts of the docker containers at different times during the day.. No idea why the first restarts didn't solve it but now it works..