Failed to get controller response and reroute to error handler (XenForo_ControllerPublic_Forum::action)

An exception occurred: Too many connections in /var/www/html/library/Zend/Db/Adapter/Mysqli.php on line 333

  1. Zend_Db_Adapter_Mysqli->_connect() in Zend/Db/Adapter/Abstract.php at line 315
  2. Zend_Db_Adapter_Abstract->getConnection() in XenForo/Application.php at line 730
  3. XenForo_Application->loadDb() in XenForo/Application.php at line 973
  4. XenForo_Application->lazyLoad() in XenForo/Application.php at line 1004
  5. XenForo_Application::get() in XenForo/Application.php at line 1609
  6. XenForo_Application::getDb() in XenForo/Session.php at line 237
  7. XenForo_Session->__construct() in XenForo/Session.php at line 324
  8. XenForo_Session::getPublicSession() in XenForo/Session.php at line 258
  9. XenForo_Session::startPublicSession() in XenForo/Controller.php at line 293
  10. XenForo_Controller->_setupSession() in XenForo/Controller.php at line 306
  11. XenForo_Controller->preDispatch() in XenForo/FrontController.php at line 350
  12. XenForo_FrontController->dispatch() in XenForo/FrontController.php at line 134
  13. XenForo_FrontController->run() in /var/www/html/index.php at line 17