Contributions to Books:
W. Hummer, Ph. Leitner, A. Michlmayr, F. Rosenberg, S. Dustdar:
"VRESCo - Vienna Runtime Environment for Service-oriented Computing";
in: "Service Engineering: European Research Results",
S. Dustdar, F. Li (ed.);
Throughout the last years, the Service-Oriented Architecture (SOA)
paradigm has been promoted as a means to create loosely coupled distributed applications.
In theory, SOAs make use of a service registry, which can be used by
providers to publish their services and by clients to discover these services in order
to execute them. However, service registries such as UDDI did not succeed and are
rarely used today. In practice, the binding often takes place at design time (for instance
by generating client-side stubs), which leads to a tighter coupling between
service endpoints. Alternative solutions using dynamic invocations often lack a data
abstraction and require developers to construct messages on XML or SOAP level.
In this paper we present VRESCo, the Vienna Runtime Environment for Serviceoriented
Computing, which addresses several distinct issues that are currently prevalent
in Service-Oriented Architecture (SOA) research and practice. VRESCo reemphasizes
the importance of registries to support dynamic selection, binding and invocation
of services. Service providers publish their services and clients retrieve the
data stored in the registry using a specialized query language. The data model distinguishes
between abstract features and concrete service implementations, which
enables grouping of services according to their functionality.An abstracted message
format allows VRESCo to mediate between services which provide the same feature but use a different message syntax. Furthermore, VRESCo allows for explicit versioning
of services. In addition to functional entities, the VRESCo service metadata
model contains QoS (Quality of Service) attributes. Clients can be configured to
dynamically rebind to different service instances based on the QoS data. The paper
presents an illustrative scenario taken from the telecommunications domain, which
serves as the basis for the discussion of the features of VRESCo.
Project Head Schahram Dustdar:
Created from the Publication Database of the Vienna University of Technology.