Ошибка: Lost connection to MySQL server during query

A Database Error Occurred
 
Error Number: 2013
 
Lost connection to MySQL server during query
 
SELECT GET_LOCK('e8d03b63969c3820c4be8d73717c0d278764b92d', 300) AS ci_session_lock
 
Filename: libraries/Session/drivers/Session_database_driver.php
 
Line Number: 326

// Shared (CI 2 and 3) Session Variables
$config['sess_cookie_name']     = 'ci_session';
$config['sess_expiration']      = 7200;
$config['sess_time_to_update'] = 300;
$config['sess_match_ip'] = false;
 
// CI 2 Session Variables
$config['sess_expire_on_close'] = false;
$config['sess_encrypt_cookie']  = false;
$config['sess_use_database']    = false;
$config['sess_table_name']      = 'sessions';
$config['sess_match_useragent'] = true; // May duplicate sessions for Safari users when true.
 
// CI 3 Session Variables
$config['sess_driver'] = 'database';
$config['sess_regenerate_destroy'] = false;
$config['sess_save_path'] = 'ci_sessions';

    /**
     * Get lock
     *
     * Acquires a lock, depending on the underlying platform.
     *
     * @param   string  $session_id Session ID
     * @return  bool
     */
    protected function _get_lock($session_id)
    {
        if ($this->_platform === 'mysql')
        {
            $arg = $session_id.($this->_config['match_ip'] ? '_'.$_SERVER['REMOTE_ADDR'] : '');
            if ($this->_db->query("SELECT GET_LOCK('".$arg."', 300) AS ci_session_lock")->row()->ci_session_lock)
            {
                $this->_lock = $arg;
                return TRUE;
            }
 
            return FALSE;
        }
        elseif ($this->_platform === 'postgre')
        {
            $arg = "hashtext('".$session_id."')".($this->_config['match_ip'] ? ", hashtext('".$_SERVER['REMOTE_ADDR']."')" : '');
            if ($this->_db->simple_query('SELECT pg_advisory_lock('.$arg.')'))
            {
                $this->_lock = $arg;
                return TRUE;
            }
 
            return FALSE;
        }
 
        return parent::_get_lock($session_id);
    }