def set_node(self, host, port, server_type=None):
        """
        Update data for a node.
        """
        node_name = "{0}:{1}".format(host, port)
        node = {
            'host': host,
            'port': port,
            'name': node_name,
            'server_type': server_type
        }
        self.nodes[node_name] = node
        return node
Update data for a node.