1. Page 1 CSISS LCenter for Spatial Information Science and Systems 03/19/2008 GeoBrain BPELPower Workflow Engine Liping Di, Genong Yu ldi@gmu.edu Center for Spatial Information Science and Systems George Mason University

2. Page 2 CSISS Center for Spatial Information Science and Systems 03/19/2008 Outline BPEL BPELPower engine –Development history –Architecture –Functions Applications –Severe weather workflow –Wildfire workflow –Geo-referencing workflow –Air-quality Lessons learnt Conclusions and Recommendations

3. Page 3 CSISS Center for Spatial Information Science and Systems 03/19/2008 BPEL Web Services Business Process Execution Language –An OASIS standard –A language for describing business processes Executable business process: Executable workflows Abstract business process: Non-executable abstract workflows Why we use BPEL? –Web Service effort: interoperability between geoprocessing applications through Web standards –Web Service workflows: Loosely coupled integration of heterogeneous systems in a variety of domains Suitable for Sensor Web in the Earth and space science

4. Page 4 CSISS Center for Spatial Information Science and Systems 03/19/2008 BPELPower BPELPower is a BPEL workflow engine developed by CSISS. –The initial version was developed in 2004 –Multiple version has been released since then Supports –BPEL4WS 1.1 –WS-BPEL 2.0 (partially supported now, in development) Released versions –Version 1.0: BPEL4WS 1.1 –Version 2.0: abstract model and instantiation –Version 3.0: asynchronous support through WS-Addressing

5. Page 5 CSISS Center for Spatial Information Science and Systems 03/19/2008 BPELPower workflow engine: architecture Major components of BPELPower workflow engine –Web Services –Human interfaces –Databases

6. Page 6 CSISS Center for Spatial Information Science and Systems 03/19/2008 Functions of BPELPower Standard-compliant –BPEL4WS 1.1/WS-BPEL 2.0 –XPath 1.0 –SOAP 1.1, 1.2 –OGC services Enhanced message encoding/decoding capabilities –XML schema –GML Extended asynchronous support –WS-Addressing RESTful Web Service support Security –WS-Security

7. Page 7 CSISS Center for Spatial Information Science and Systems 03/19/2008 Design a workflow Support packaging of BPEL project using commercial BPEL designer –Oracle BPEL Designer

8. Page 8 CSISS Center for Spatial Information Science and Systems 03/19/2008 BPEL Process management BPELPower supports efficient management of BPEL processes –Deployment/undeployment –Deployed workflow Standard Web service –SOAP service –RESTful service Human portal interface

9. Page 9 CSISS Center for Spatial Information Science and Systems 03/19/2008 Instantiation service Web service for Abstract model instantiation –Manage abstract workflow –Instantiation of abstract model

10. Page 10 CSISS Center for Spatial Information Science and Systems 03/19/2008 Use Case 1 – severe weather detection and tracking Workflow –Inputs of initial parameters –WCS data sources –Severe weather detection –Optional transactions to fed back results into WFS –Severe weather tracking –Optional transaction to fed back results into WFS The workflow supports transaction for WCS & WFS

11. Page 11 CSISS Center for Spatial Information Science and Systems 03/19/2008 Case 2 – geo-referencing Workflow steps –planning request to the SPS User as actor –email notification –Retrieve observation from the SOS –Feed the observations into the JPIP server through secured transaction –Add the data along with description into WCS through transaction –Alert the data availability through SAS to all subscribed users

12. Page 12 CSISS Center for Spatial Information Science and Systems 03/19/2008 Georeferencing logical workflow

13. Page 13 CSISS Center for Spatial Information Science and Systems 03/19/2008 Geo-referencing workflow Workflow –Demonstrated at OWS 5 –SPOT Image Asynchronous –SPS based on WNS WS-Addressing Callback pattern –Notification of data availability through SAS XMPP Publish/subscribe pattern

14. Page 14 CSISS Center for Spatial Information Science and Systems 03/19/2008 Case 3 - Collaborative Wildfire Monitoring collaboration –Standard web services –Automated workflow through BPEL/BPELPower

15. Page 15 CSISS Center for Spatial Information Science and Systems 03/19/2008 Abstract model instantiation Abstract model –On-demand automatic generation of fire products

16. Page 16 CSISS Center for Spatial Information Science and Systems 03/19/2008 RESTful service interface RESTfull support –RESTfull interfaces to use workflows as resources

17. Page 17 CSISS Center for Spatial Information Science and Systems 03/19/2008 Case 4 – air quality Air quality workflow –Abstract model designer for designing the abstract model –Air quality was represented in assimilated WMS representation

18. Page 18 CSISS Center for Spatial Information Science and Systems 03/19/2008 Lessons learnt Complexity of GML Newly-supported message encoding/decoding –KML –SensorML Further developments should enhance the support of OGC specifications –WNS –SAS –OWS framework: getCapabilities Specification extension –BPEL4OWS Fully utilization of getCapabilities Complete support of OGC-specific message notification mechanism, e.g. WNS, SAS Message encoding/decoding, e.g. KML, GML Geobrain.laits.gmu.edu

19. Page 19 CSISS Center for Spatial Information Science and Systems 03/19/2008 Conclusions BPEL can be used for describing geospatial workflow BPELPower engine has been efficiently applied in many cases –Loosely coupled –Heterogeneous services

20. Page 20 CSISS Center for Spatial Information Science and Systems 03/19/2008 Further information Websites –http://geobrain.laits.gmu.eduhttp://geobrain.laits.gmu.edu –http://csiss.gmu.edu/sensorwebhttp://csiss.gmu.edu/sensorweb Demonstrations –http://geobrain.laits.gmu.edu/doc/ows4Demo/demo.swfhttp://geobrain.laits.gmu.edu/doc/ows4Demo/demo.swf

21. Page 21 CSISS Center for Spatial Information Science and Systems 03/19/2008 Acknowledgement BPELPower is developed with funding support from NASA REASoN program, NASA ESTO AIST program, and OGC Web Service Initiatives.