Atomic commitment in database systems over active networks

Traditional communication networks have functioned only to deliver information packets from one end system to another. As the cost of computing power continues to decrease, it is worthwhile to consider the benefits of adding more of that computing power to the network itself, either to enhance services or to trade off against other costs such as time, bandwidth and storage. This new area of research is called Active Networking. Active networking represents a new approach in which network switches or nodes perform customized computing as the messages flowing through them. This paper proposes a novel approach to atomic commitment of transactions in distributed database systems. In our approach, active nodes participate in the process of atomic commitment of distributed transactions by maintaining passive "blackboards" which record voting status of participant subtransactions. One active node is delegated the coordinator function so that when rendezvous is there, commit decisions can be made. Since the decision is made from an internal network node (selected to be close to the participant nodes), the uncertainty time delay can be significantly reduced. This is especially critical in wide area networks. Other active nodes can be used to suppress duplicated votes sent in the upstream direction. Additionally, once a negative vote is received at any active node, children participants can be notified of the abort decision immediately and therefore much earlier than would otherwise be possible. This approach is shown to yield performance improvements over traditional methods, in terms of delay and network message traffic.