Distributed transactions require transaction processing support either from their communications protocols or from protocols at some higher layer. The peer-to-peer environment is supported by IBM's SNA (i.e., LU6.2) and follows the chained transactional paradigm. As OSI/TP began specifying the flows for transactional support, the notion of unchained transactional support as opposed to the chained nature of LU6.2 transactions gradually developed (OSI/TP supports both chained and unchained transactions). This makes the coexistence of applications requiring both kinds of transaction processing support on a platform that supports only chained transactions problematic and reduces the interoperability of communication protocols providing transactional support. Our work identified and addressed the above problems by identifying the extra functionality provided by unchained transactions over chained transactions. It then showed how a protocol/platform that provides only chained transactional support can provide the functionality of unchained transactions, and without using the notion of chained or unchained transactions at the API. It also studied an efficient way by which protocols providing only chained support can provide the functionality of unchained transactions using the X/Open TX API based on OSI/TP's Chained and Unchained Functional Units. In all solutions the notion of "context" as is presented below was instrumental.

Related Publications