Magento – Exception: SQLSTATE[HY000] [2002] Can’t connect to local MySQL server through socket

I have installed Magento Community Edition 1.9.0.1 on Digitalocean application. I extracted the error report and listed below, can you help take a look and let me know what to do in order to fix?

a:4:{i:0;s:109:"SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111)";i:1;s:2884:"#0 /var/www/html/magento/lib/Zend/Db/Adapter/Pdo/Mysql.php(109): Zend_Db_Adapter_Pdo_Abstract->_connect()
#1 /var/www/html/magento/lib/Varien/Db/Adapter/Pdo/Mysql.php(320): Zend_Db_Adapter_Pdo_Mysql->_connect()
#2 /var/www/html/magento/lib/Zend/Db/Adapter/Abstract.php(460): Varien_Db_Adapter_Pdo_Mysql->_connect()
#3 /var/www/html/magento/lib/Zend/Db/Adapter/Pdo/Abstract.php(238): Zend_Db_Adapter_Abstract->query('SET NAMES utf8', Array)
#4 /var/www/html/magento/lib/Varien/Db/Adapter/Pdo/Mysql.php(428): Zend_Db_Adapter_Pdo_Abstract->query('SET NAMES utf8', Array)
#5 /var/www/html/magento/app/code/core/Mage/Core/Model/Resource.php(169): Varien_Db_Adapter_Pdo_Mysql->query('SET NAMES utf8')
#6 /var/www/html/magento/app/code/core/Mage/Core/Model/Resource.php(110): Mage_Core_Model_Resource->_newConnection('pdo_mysql', Object(Mage_Core_Model_Config_Element))
#7 /var/www/html/magento/app/code/core/Mage/Core/Model/Resource/Db/Abstract.php(320): Mage_Core_Model_Resource->getConnection('core_write')
#8 /var/www/html/magento/app/code/core/Mage/Core/Model/Resource/Db/Abstract.php(350): Mage_Core_Model_Resource_Db_Abstract->_getConnection('write')
#9 /var/www/html/magento/app/code/core/Mage/Core/Model/Resource/Db/Abstract.php(335): Mage_Core_Model_Resource_Db_Abstract->_getWriteAdapter()
#10 /var/www/html/magento/app/code/core/Mage/Core/Model/Resource/Db/Abstract.php(360): Mage_Core_Model_Resource_Db_Abstract->_getReadAdapter()
#11 /var/www/html/magento/app/code/core/Mage/Core/Model/Resource/Db/Collection/Abstract.php(134): Mage_Core_Model_Resource_Db_Abstract->getReadConnection()
#12 /var/www/html/magento/app/code/core/Mage/Core/Model/Config.php(1348): Mage_Core_Model_Resource_Db_Collection_Abstract->__construct(Object(Mage_Core_Model_Resource_Website))
#13 /var/www/html/magento/app/code/core/Mage/Core/Model/Config.php(1380): Mage_Core_Model_Config->getModelInstance('core_resource/w...', Object(Mage_Core_Model_Resource_Website))
#14 /var/www/html/magento/app/Mage.php(491): Mage_Core_Model_Config->getResourceModelInstance('core/website_co...', Object(Mage_Core_Model_Resource_Website))
#15 /var/www/html/magento/app/code/core/Mage/Core/Model/Abstract.php(208): Mage::getResourceModel('core/website_co...', Object(Mage_Core_Model_Resource_Website))
#16 /var/www/html/magento/app/code/core/Mage/Core/Model/Abstract.php(213): Mage_Core_Model_Abstract->getResourceCollection()
#17 /var/www/html/magento/app/code/core/Mage/Core/Model/App.php(608): Mage_Core_Model_Abstract->getCollection()
#18 /var/www/html/magento/app/code/core/Mage/Core/Model/App.php(466): Mage_Core_Model_App->_initStores()
#19 /var/www/html/magento/app/code/core/Mage/Core/Model/App.php(349): Mage_Core_Model_App->_initCurrentStore('', 'store')
#20 /var/www/html/magento/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#21 /var/www/html/magento/index.php(87): Mage::run('', 'store')
#22 {main}";s:3:"url";s:1:"/";s:11:"script_name";s:10:"/index.php";}