Summary:
Business Process Execution Language (BPEL) has become a standard for describing
the interactions between business processes. Until recently, only centralized
BPEL engines were used to orchestrate the process interactions, while
scalability and robustness were addressed via engine replication. To address
these issues we propose a fully decentralized solution: by employing a content
based publish/subscribe mechanism on top of a distributed hash table network of
peers, we specify a distributed orchestration engine. Furthermore, we extend a
previously proposed model that maps BPEL activities into a subscription
language, thereby decentralizing business process execution. The
publish/subscribe mechanism provides efficient and flexible means for
information producers
and consumers to exchange data, while the underlying peer-to-peer topology
offers scalable query and message propagation. An implementation of the
proposed approach is provided and tested over the PeerSim simulator. We
evaluated our system in terms of efficiency and effectiveness, i.e.,
scalability, robustness, and overhead.
Keywords:
BPEL, Orchestration Engines, Business Process Execution, Publish/Subscribe systems, Peer-to-Peer systems
