A practical technique for asynchronous transaction processing

Asynchronous transaction processing extends traditional on-line transaction processing (TP) to improve performance of distributed systems by alleviating the serializability (SR) bottleneck. For example, epsilon serializability (ESR) uses divergence control algorithms to allow more concurrency by permitting limited non-SR interleavings. In a distributed environment, ESR relaxes commit and abort dependencies among transactions, allowing transactions to commit asynchronously. A second example, chopping up transactions allows more concurrency by dividing transactions into smaller pieces and thus reduces resource holding time. Chopping transactions enforces no commit protocols among pieces from one original transaction, allowing each piece to commit asynchronously. We combine the benefits of ESR and chopping transactions by designing three new methods that chop transactions and run them under ESR. The practical applicability of our technique is enhanced by two factors: (1) chopping transactions does not require changes in existing TP systems, and (2) ESR support has already been prototyped on a commercial TP system