A fatal error has occurred

Could not instantiate PDO. PDOException: SQLSTATE[HY000] [2002] No such file or directory

in /usr/local/lib/php/Horde/Db/Adapter/Pdo/Base.php:48
 1. Horde_Registry::appInit() /usr/local/apache/htdocs/services/portal/index.php:15
 2. Horde_Registry->pushApp() /usr/local/lib/php/Horde/Registry.php:299
 3. Horde_Core_LoginTasks->runTasks() /usr/local/lib/php/Horde/Registry.php:1650
 4. Horde_LoginTasks->runTasks() /usr/local/lib/php/Horde/Core/LoginTasks.php:48
 5. Horde_LoginTasks_Task_AdminCheck->execute() /usr/local/lib/php/Horde/LoginTasks.php:216
 6. Horde_Core_Db_Migration->getMigrator() /usr/local/apache/htdocs/lib/LoginTasks/Task/AdminCheck.php:54
 7. Horde_Injector->getInstance() /usr/local/lib/php/Horde/Core/Db/Migration.php:117
 8. Horde_Injector->createInstance() /usr/local/lib/php/Horde/Injector.php:272
 9. Horde_Injector_Binder_Factory->create() /usr/local/lib/php/Horde/Injector.php:238
10. Horde_Core_Factory_DbBase->create() /usr/local/lib/php/Horde/Injector/Binder/Factory.php:119
11. Horde_Core_Factory_Db->create() /usr/local/lib/php/Horde/Core/Factory/DbBase.php:17
12. Horde_Core_Factory_Db->_createDb() /usr/local/lib/php/Horde/Core/Factory/Db.php:106
13. Horde_Db_Adapter_Base->__construct() /usr/local/lib/php/Horde/Core/Factory/Db.php:189
14. Horde_Db_Adapter_Pdo_Mysql->connect() /usr/local/lib/php/Horde/Db/Adapter/Base.php:157
15. Horde_Db_Adapter_Pdo_Base->connect() /usr/local/lib/php/Horde/Db/Adapter/Pdo/Mysql.php:63

Details

The full error message is logged in Horde's log file, and is shown below only to administrators. Non-administrative users will not see error details.