Uncaught exception thrown in session handler.

PDOException: SQLSTATE[HY000]: General error: 7 server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request.: SELECT 1 AS expression FROM {sessions} sessions WHERE ( (sid = :db_condition_placeholder_0) AND (ssid = :db_condition_placeholder_1) ); Array ( [:db_condition_placeholder_0] => 1HeNvy0kkLlXiVQxonu1JDzPrPRJuI8SZqwMx8f1I7g [:db_condition_placeholder_1] => ) in _drupal_session_write() (line 212 of /var/www/vh/library/includes/session.inc).