Hello I am a phd student and during this period i am dealing with workflow optimization problems in distributed environments. I would like to ask, if there are exist any cases where if the order of task invocation in a scientific workflow changes its performance changes too without, however, affecting the produced results. In the following, a present a small use case of the problem i am interested in:
Suppose that a company wants to obtain a list of email addresses of potential customers selecting only those who have a good payment history for at least one card and a credit rating above some threshold. The company has the right to use the following web services WS1 : SSN id (ssn, threshold) -> credit rating (cr) WS2 : SSN id (ssn) -> credit card numbers (ccn) WS3 : card number (ccn, good) -> good history (gph) WS4 : SSN id (ssn) -> email addresses (ea) The input data containing customer identifiers (ssn) and other relevant information is stored in a local data resource. Two possible web service linear workflows that can be formed to process the input data using the above services are C1 = WS2,WS3,WS1,WS4 and C2 = WS1,WS2,WS3,WS4. In the first workflow, first, the customers having a good payment history are initially selected (WS2,WS3), and then, the remaining customers whose credit history is below some threshold are filtered out (through WS1). The C2 workflow performs the same tasks in a reverse order. The above linear workflows may have different performance; if WS3 filters out more data than WS1, then it will be more beneficial to invoke WS3 before WS1 in order for the subsequent web services in the workflow to process less data. It would be very useful to know if there exist similar scientific workflow examples (where the order of task invocation can change and it is not known a-priori by the user, while the workflow performance depends on the workflow task invocation order) and if you are interested in extending taverna with optimization algorithms for such workflows. I am asking because i have recently developed an optimization algorithm for this problem and i would like to test its performance in a real-world workflow management system with real-world workflows. P.S.: references to publications or any other information dealing with scientific workflows of the above rationale will be extremely useful. Thank you very much for your time ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2d-c2 _______________________________________________ taverna-hackers mailing list [email protected] Web site: http://www.taverna.org.uk Mailing lists: http://www.taverna.org.uk/about/contact-us/ Developers Guide: http://www.taverna.org.uk/developers/
