Supporting Reliable Transactional Business Processes by Publish/Subscribe Techniques
Christoph Schuler6
, Heiko Schuldt6
and Hans-Jörg Schek6 
| (6) |
Swiss Federal Institute of Technology (ETH), Institute of Information Systems, ETH Zentrum, 8092 Zürich, Switzerland |
Abstract
Processes have increasingly become an important design principle for complex intra- and inter-organizational e-services. In
particular, processes allow to provide value-added services by seamlessly combining existing e-services into a coherent whole,
even across corporate boundaries. Process management approaches support the definition and the execution of predefined processes
as distributed applications. They ensure that execution guarantees are observed even in the presence of failures and concurrency.
The implementation of a process management execution environment is a challenging task in several aspects. First, the processes
to be executed are not necessarily static and follow a prede- fined pattern but must be generated dynamically (e.g., choosing
the best offer in a pre-sales interaction). Second, deferring the execution of some application services in case of overload
or unavailability is often not acceptable and must be avoided by exploiting replicated services or even by automatically adding
such services, and by monitoring and balancing the load. Third, in order to avoid a bottleneck at the process coordinator
level, a centralized implementation must be avoided as much as possible. Hence, a framework is needed which supports both
the modularization of the process coordinator’s functionality and the flexibility needed for dynamically generating and adopting
processes. In this paper we show how publish/subscribe techniques can be used for the implementation of process management.
We show how the overall architecture looks like when using a computer cluster and publish/subscribe components as the basic
infrastructure to drive the enactment of processes. In particular we describe how load balancing, process navigation, failure
handling, and process monitoring is supported with minimal intervention of a centralized coordinator.
Part of this work has been funded by the Swiss National Science Foundation under the project INVENT.
References secured to subscribers.