lxd/db/node.go
func (c *ClusterTx) NodeHeartbeat(address string, heartbeat time.Time) error {
	stmt := "UPDATE nodes SET heartbeat=? WHERE address=?"
	result, err := c.tx.Exec(stmt, heartbeat, address)
	if err != nil {
		return err
	}
	n, err := result.RowsAffected()
	if err != nil {
		return err
	}
	if n != 1 {
		return fmt.Errorf("expected to update one row and not %d", n)
	}
	return nil
}
func (c *ClusterTx) NodeHeartbeat(address string, heartbeat time.Time) error {
	stmt := "UPDATE nodes SET heartbeat=? WHERE address=?"
	result, err := c.tx.Exec(stmt, heartbeat, address)
	if err != nil {
		return err
	}
	n, err := result.RowsAffected()
	if err != nil {
		return err
	}
	if n != 1 {
		return fmt.Errorf("expected to update one row and not %d", n)
	}
	return nil
}
// NodeHeartbeat updates the heartbeat column of the node with the given address.