A method of performing transaction processing operations at computing apparatus is provided, together with computing apparatus adapted to manage these operations. The computing apparatus includes a programmed processor adapted to provide the following functional elements. A agent manager node is adapted to install and deinstall transaction processing nodes. A transaction operation rules database holds transaction operation rules. An interface to a transaction processing infrastructure receives transaction data for the transaction processing operations. The transaction processing nodes are adapted to perform the transaction processing operation on the transaction data using the transaction operation rules under control of the agent manager node.