1. A PPARC funded project Common Execution Architecture Paul Harrison IVOA Interoperability Meeting Cambridge MA 23-28 May 2004

2. 2 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture Introduction Common Execution Architecture (CEA) An attempt to model how an application is run in the Virtual Observatory An application is any process that consumes or produces data Designed primarily to work in web services environment A set of schema and WSDL definitions

3. 3 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture Motivation To create a model of an application VO infrastructure only has to deal with a single application model Application writers know how to interface VO Provide higher level description than WSDL Restrict to manageable subset Provide specific semantics for astronomical Quantities Provide extra information - e.g. Defaults Data flow does not necessarily follow call tree Asynchronous Operation

4. 4 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture History The desire to be able to create a workflow Engine in AstroGrid Derived from the Iteration 4 Command Line Application Controller experiences. It is a work-in-progress Will definitely evolve in next few months

5. 5 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture Application Model

6. 6 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture Components Application Command line, web service Common Execution Controller Controls the application, interacts with the other components Invoking process Workflow, web service, script Monitoring Service Receives the status messages Storage Service

7. 7 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture Component Interactions UML UML Sequence Diagram The monitoring service could be same as invoking service The only guaranteed status message is the final one The results of running the application are not returned directly to the invoking process. The destination is implicit in the specification of the output parameters

8. 8 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture How to use it AstroGrid Iteration 5 released at end of month Look at test environment!! AstroGrid exposes all these components as web services Workflow is an xml document Not limited to using AstroGrid portal Script Extend existing VO Tools (e.g. Aladin)

9. 9 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture Deployment Scenario UMLUML Diagram Command line applications that are wrapped by specialized CommonExecutionControllers that make a compute farm Web services proxy component that can act as an adapter between a generic web service and the CommonExecutionConnector interface Web services proxy can be localised with a web service so that the results returned can be stored locally thus minimising network traffic

10. 10 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture How to integrate your Applications Command Line Execution Controller already exists CEA web service wrapper for UNIX command lines Interacts with workflow, MySpace Simply a case of configuring the application in the registry  If you want to wrap functionality easy to do by extending the CommandLineApplication class. Implement the CommonExecutionConnector Interface directly.

11. 11 18-Dec-15IVOA Interoperability Meeting: Common Execution Architecture Summary CEA creates an environment to send messages to and from applications. Implemented in AstroGrid Workflow with a CEC for Command Line applications Configuration only web service. Iteration 6 will produce general CEC proxy for any web service. See maven page http://www.astrogrid.org/maven/docs/snapshot/ap plications/