Presumed Abort Protocols
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-08
This invention relates to a method for achieving synchronization of recoverable states among multiple nodes in spite of faults. A distributed transaction involving one or more data base sites may be manifest as a hierarchy of processes. The hierarchy is rooted in a coordinator of the transaction with other processes being tree-graph related. When the processes complete their activities, a commit protocol is invoked. Presumed abort (PA) is an extension of the two-phase (2P) commit protocol. PA is optimized for read-only transactions and a class of multi-site update transactions. The optimizations result in reduced inter-site message traffic and log writes, and, consequently, a better response time for such transactions.