Two-Phase Commit Processing with Restructured Commit Tree

Extensive research has been carried out in search for an efficient atomic commit protocol and many optimizations have been suggested to improve the basic two-phase commit protocol, either for the normal or failure case. Of these optimizations, the read-only optimization is the best known and most widely used, whereas the flattening of-the-commit-tree optimization is the most recent one proposed for Internet transactions. In this paper, we study in depth the combined use of these two optimizations and show the limitations of the flattening-of-the-commit-tree method in committing large trees. Further, we propose a new restructuring method of the commit tree and show using simulation that it performs better than flattening method even when dealing with large trees.