| Send an e-mail to
| creator |
Reimann, Peter
| | date |
2008-08-18
| | | | description |
191 pages
| |
In the Web Services Environment, the standard to model business
processes is the Web Services Business Process Execution Language
(WS-BPEL or BPEL for short), which has been developed by the
Organization for the Advancement of Structured Information Standards
(OASIS). In BPEL, it is possible to call Web Services that
encapsulate SQL-specific functionality and hide the corresponding
data stores. In addition, leading developers of workflow systems
(Oracle, Microsoft, IBM) offer the opportunity to tightly integrate
SQL-specific functionality into BPEL. By extending BPEL with
additional activity types, it is possible to make SQL activities
visible in BPEL processes. This facilitates an easier way of
modeling data-intensive business processes.
The Institute of Parallel and Distributed Systems at the University
of Stuttgart has proposed a heuristic approach to optimize data
processing in business processes. This approach is based on rewrite
rules which transform data-specific parts of a business process in
such a way that the resulting process shows an improved performance
and can be executed in a more efficient way. Furthermore, the
rewrite rules must not change the semantics of the original process.
They are applied to a business process in a multi-stage control
strategy. Until now, the approach will only be applicable if some
assumptions regarding the involved business process hold. One of
these assumptions is that all data management activities of the
business process are issued against the same centralized database
system. In a practical setting, business processes often access more
than one data source, and the involved data sources distinguish
themselves by a high degree of heterogeneity. Federated database
technology can be used to hide the heterogeneity of multiple data
sources and to provide a uniform access to them.
This thesis investigates what changes need to be done to the
current, heuristic optimization approach in order to support the
optimization of a business process in two new cases regarding the
application environment of the process. In the first case, the
business process accesses multiple heterogeneous or homogeneous,
centralized database systems. In the second one, it accesses one
federated database system integrating multiple database systems.
Furthermore, new optimization techniques are identified, in
particular optimization techniques which are applicable in one or
both of the new application environments, and tested for their
suitability for the current, heuristic optimization approach. If new
optimization techniques are suitable for this approach, according
rewrite rules are defined and integrated into the existing set of
rewrite rules. The effectiveness of each current and new rewrite
rule is tested by measuring the durations of corresponding original
and optimized processes.
| | format |
application/pdf
| | 2296747 Bytes | |