Lookup NU author(s): Frederic Ranno,
Emeritus Professor Santosh Shrivastava,
Dr Stuart Wheater
An increasing number of distributed applications are being constructed by composing them out of existing applications. The resulting applications can be very complex in structure, containing many temporal and dataflow dependencies between their constituent applications. An additional complication is that the execution of such an application may take a long time to complete, and may contain long periods of inactivity, often due to the constituent applications requiring user interactions. In a distributed environment, it is inevitable that long running applications will require support for fault-tolerance and dynamic reconfiguration: machines may fail, services may be moved or withdrawn and application requirements may change. In such an environment it is essential that the structure of applications can be modified to reflect these changes. This paper describes the design and implementation of a coordination language and the supporting execution environment for expressing the run-time composition of distributed applications and their dependencies. The system supports interoperability as it has been designed and implemented as a set of CORBA services. Dynamic control is made possible because the execution environment is built using a transactional workflow management system where sets of inter-related tasks can be carried out and supervised in a dependable manner. The paper describes how relevant ideas from the fields of workflow management and software architectures can be combined to provide an advanced application construction and execution environment, using distributed objects and middleware technologies.
Author(s): Ranno F, Shrivastava SK, Wheater SM
Editor(s): Konig, H., Geihs, K.G. and Preuss, T.
Publication type: Conference Proceedings (inc. Abstract)
Conference Name: 1st IFIP TC 6 WG 6.1 International Working Conference on Distributed Applications and Interoperable Systems (DAIS '97)
Year of Conference: 1997
Publisher: Chapman & Hall
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