SQLSTATE[HY000] [2002] Connection refused

Hints
We are unable to connect database. Please edit databse definition xml (Path: development/definition/database.xml)

Trace:
#0 /var/www/clients/client0/web1/web/apprain/base/abstract.php(49): appRain_Base_Modules_Database_Pdo_Mysql->Connect(Array)
#1 /var/www/clients/client0/web1/web/apprain/base/appmodel.php(111): appRain_Base_Abstract->get_conn()
#2 /var/www/clients/client0/web1/web/apprain/base/appmodel.php(126): Apprain_Base_appModel->findAll('type = 'Compone...')
#3 /var/www/clients/client0/web1/web/apprain/base/objects.php(48): Apprain_Base_appModel->callByFiled('findAllByType', 'Component')
#4 /var/www/clients/client0/web1/web/apprain/base/component.php(63): appRain_Base_Objects->__call('findAllByType', Array)
#5 /var/www/clients/client0/web1/web/apprain/base/component.php(63): CoreresourceModel->findAllByType('Component')
#6 /var/www/clients/client0/web1/web/apprain/base/component.php(75): appRain_Base_component->getCoreResourceInstance()
#7 /var/www/clients/client0/web1/web/apprain/base/modules/definition.php(216): appRain_Base_component->status()
#8 /var/www/clients/client0/web1/web/apprain/base/modules/definition.php(136): appRain_Base_Modules_Definition->parseComponentList()
#9 /var/www/clients/client0/web1/web/app.php(217): appRain_Base_Modules_Definition->getComponentList()
#10 /var/www/clients/client0/web1/web/webroot/index.php(20): App::run()
#11 {main}