Optimal Stratification of Transactions

The performance of applications is influenced by the way its operations are grouped into global transactions. This in turn influences the performance of business processes which utilize these applications as implementations of process activities/steps. Stratified transactions, as produced by the stratification approach presented in this paper, is a way to manage a global transaction by combining the more elemental transactions coordinated using the two-phase commit protocol and queued transactions. The stratification approach can be applied for optimally fragmenting workflow-based service compositions and support the out- and in-sourcing scenarios. This paper formally models global transactions and investigates the mechanisms for building an optimally stratified transaction relying on formally defined evaluation criteria. We investigate the applicability of local search algorithms to the optimization of transaction stratification. In particular we consider hill-climbing, simulated annealing, and a novel hybrid method combining both approaches.