The analysis of a commercial implementation of multiple 2 phase commitment protocols within a single operating system integrity control layer

An examination is made of the generic attributes of distributed atomic commitment protocols. It is shown how a single set of transaction states and journal phase marks can support two different protocols which have completely different message contents. Transaction state transitions which are protocol-dependent are controlled by the communication protocol manager by having integrity control call prior to the transitions. Integrity control remains oblivious to the communication protocol being used. This results in a smaller, simpler integrity control module whose only responsibility is the management of the state transitions of the host-based transaction. It is common to discuss distributed atomic commitment protocols solely in terms of the messages passed between the participants. The author has discussed these protocols on the basis of the host transaction-state transitions that are required.<>